担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We report the discovery of a quasar at z = 7.07, which was selected from the deep multi-band imaging data collected by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. This quasar, HSC J124353.93 +010038.5, has an order of magnitude lower luminosity than do the other known quasars at z > 7. The rest-frame ultraviolet absolute magnitude is M-1450 = -24.13 +/- 0.08 mag and the bolometric luminosity is L-bol = (1.4 +/- 0.1) x 10(46) erg s(-1). Its spectrum in the optical to near-infrared shows strong emission lines, and shows evidence for a fast gas outflow, as the C IV line is blueshifted and there is indication of broad absorption lines. The Mg IT-based black hole mass is M-BH = (3.3 +/- 2.0) x 10(8) M-circle dot, thus indicating a moderate mass accretion rate with an Eddington ratio) lambda(Edd) = 0.34 0.20. It is the first z > 7 quasar with sub-Eddington accretion, besides being the third most distant quasar known to date. The luminosity and black hole mass are comparable to, or even lower than, those measured for the majority of low-z quasars discovered by the Sloan Digital Sky Survey, and thus this quasar likely represents a z > 7 counterpart to quasars commonly observed in the low-z universe.

DOI： 10.3847/2041-8213/ab0216

Web of Science

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/2041-8213/ab0216

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We present new measurements of the quasar luminosity function (LF) at z similar to 6 over an unprecedentedly wide range of the rest-frame ultraviolet luminosity M-1450 from -30 to -22 mag. This is the fifth in a series of publications from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which exploits the deep multiband imaging data produced by the Hyper Suprime-Cam Subaru Strategic Program survey. The LF was calculated with a complete sample of 110 quasars at 5.7 <= z <= 6.5, which includes 48 SHELLQs quasars discovered over 650 deg(2) and 63 brighter quasars discovered by the Sloan Digital Sky Survey and the Canada-France-Hawaii Quasar Survey (including one overlapping object). This is the largest sample of z similar to 6 quasars with a well-defined selection function constructed to date, which has allowed us to detect significant flattening of the LF at its faint end. A double power-law function fit to the sample yields a faint-end slope alpha = -1.23(-0.34)(+0.44), a bright-end slope beta = -2.73(-0.31)(+0.23), a break magnitude M*(1450) = -24.90(-0.90)(+0.75), and a characteristic space density Phi* = 10.9(-6.8)(+10.0) Gpc(-3) mag(-1). Integrating this best-fit model over the range -18 < M-1450 < -30 mag, quasars emit ionizing photons at the rate of <(n)over dot>(ion) = 10(48.8 +/- 0.1) s(-1) Mpc(-3) at z = 6.0. This is less than 10% of the critical rate necessary to keep the intergalactic medium ionized, which indicates that quasars are not a major contributor to cosmic reionization.

DOI： 10.3847/1538-4357/aaee7a

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/869/i=2/a=150?key=crossref.2c0b86f4dd34fe0fa70ad5769dd5c994

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We report the discovery of 41 new high-z quasars and luminous galaxies that were spectroscopically identified at 5.7 <= z <= 6.9. This is the fourth in a series of papers from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, based on the deep multi-band imaging data collected by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. We selected the photometric candidates using a Bayesian probabilistic algorithm and then carried out follow-up spectroscopy with the Gran Telescopio Canarias and the Subaru Telescope. Combined with the sample presented in the previous papers, we have now spectroscopically identified 137 extremely red HSC sources over about 650 deg(2),which includes 64 high-z quasars, 24 high-z luminous galaxies, 6 [O III] emitters at z similar to 0.8, and 43 Galactic cool dwarfs (low-mass stars and brown dwarfs). The new quasars span in luminosity range from M-1450 similar to -26 to -22 mag, and continue to populate luminosities a few magnitudes lower than have been probed by previous wide-field surveys. In a companion paper, we derive the quasar luminosity function at z similar to 6 over an unprecedentedly wide range of M-1450 similar to -28 to -21 mag, exploiting the SHELLQs and other survey outcomes.

DOI： 10.3847/1538-4365/aac724

Web of Science

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4365/aac724

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

We present spectroscopic identification of 32 new quasars and luminous galaxies discovered at 5.7 < z <= 6.8. This is the second in a series of papers presenting the results of the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which exploits the deep multi-band imaging data produced by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. The photometric candidates were selected by a Bayesian probabilistic algorithm, and then observed with spectrographs on the Gran Telescopio Canarias and the Subaru Telescope. Combined with the sample presented in the previous paper of this series, we have now identified 64 HSC sources over about 430 deg(2), which include 33 high-z quasars, 14 high-z luminous galaxies, two [OIII] emitters at z similar to 0.8, and 15 Galactic brown dwarfs. The new quasars have considerably lower luminosity (M-1450 similar to -25 to -22 mag) than most of the previously known high-z quasars. Several of these quasars have luminous (>10(43) erg s(-1)) and narrow (< 500 kms(-1)) Ly alpha lines, and also a possible mini broad-absorption-line system of N V lambda 1240 in the composite spectrum, which clearly separate them from typical quasars. On the other hand, the high-z galaxies have extremely high luminosities (M-1450 similar to -24 to -22 mag) compared to other galaxies found at similar redshifts. With the discovery of these new classes of objects, we are opening up new parameter spaces in the high-z Universe. Further survey observations and follow-up studies of the identified objects, including the construction of the quasar luminosity function at z similar to 6, are ongoing.

DOI： 10.1093/pasj/psx046

Web of Science

Scopus

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/0004-637x/828/1/26

Scopus

researchmap

その他リンク： http://stacks.iop.org/0004-637X/828/i=1/a=26?key=crossref.5ba33c4bdda5692bbf2571002db366e2

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-637x/811/2/91

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/811/i=2/a=91?key=crossref.d0dad123c607275c816c38a5fd5fb894

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-637x/780/2/162

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/780/i=2/a=162?key=crossref.116f9ca9597d8d228763419ab2774dd3

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-6256/144/6/159

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Astronomical Society of Japan  

DOI： 10.1093/pasj/64.3.44

Web of Science

CiNii Books

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-637x/750/1/54

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-6256/142/2/64

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-637x/736/2/119

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1111/j.1365-2966.2010.17464.x

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1111/j.1365-2966.2010.16456.x

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1086/591022

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1086/524193

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1086/518399

Web of Science

researchmap

担当区分：筆頭著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Astronomical Society of Japan  

DOI： 10.1093/pasj/57.4.563

Web of Science

CiNii Books

researchmap

掲載種別：研究論文（学術雑誌）  

HSC 120505.09-000027.9 (J1205-0000) is one of the highest redshift (z = 6.72) dust-reddened quasars (red quasars) known to date. We present an improved analysis of Atacama Large Millimeter/submillimeter Array data of the [C ii] 158 μm line and the underlying rest-frame far-infrared (FIR) continuum emission, previously reported in T. Izumi et al. (2021b), toward J1205-0000. Red quasars are thought to be a transitional phase from an obscured starburst to a luminous blue quasar, in some cases associated with massive outflows driven by the active galactic nucleus (AGN). J1205-0000 has a high FIR luminosity, LFIR = 2.5 × 1012 L⊙ and a total IR luminosity of LTIR = 3.5 × 1012 L⊙, corresponding to a star formation rate of ∼528 M⊙ yr−1. With the [C ii]-based dynamical mass of ∼1 × 1011 M⊙, we conclude that J1205-0000 is hosted by a starburst galaxy. In contradiction to T. Izumi et al., our improved analysis shows no hint of a broad component in the [C ii] line spectrum. Thus there is no evidence for a host galaxy-scale fast [C ii] outflow, despite the fact that J1205-0000 has fast nuclear ionized outflows seen in the rest-frame UV. We explore several scenarios for this discrepancy (e.g., the early phase of AGN feedback, reliability of the [C ii] line as a tracer of outflows), and we claim that it is still too early to conclude that there is no significant negative AGN feedback on star formation in this red quasar.

DOI： 10.3847/1538-4357/ada943

Scopus

researchmap

掲載種別：研究論文（学術雑誌）  

We present Atacama Large Millimeter/submillimeter Array [C ii] 158 μm line and underlying far-IR continuum emission observations (0.″57 × 0.″46 resolution) toward a quasar-quasar pair system recently discovered at z = 6.05. The quasar nuclei (C1 and C2) are faint (M 1450 ≳ −23 mag), but we detect very bright [C ii] emission bridging the 12 kpc between the two objects and extending beyond them (total luminosity L [C ii] ≃ 6 × 109 L ⊙). The [C ii]-based total star formation rate of the system is ∼550 M ⊙ yr−1 (the IR-based dust-obscured star formation is ∼100 M ⊙ yr−1), with a [C ii]-based total gas mass of ∼1011 M ⊙. The dynamical masses of the two galaxies are large (∼9 × 1010 M ⊙ for C1 and ∼5 × 1010 M ⊙ for C2). There is a smooth velocity gradient in [C ii], indicating that these quasars are a tidally interacting system. We identified a dynamically distinct, fast-[C ii] component around C1: detailed inspection of the line spectrum there reveals the presence of a broad-wing component, which we interpret as the indication of fast outflows with a velocity of ∼600 km s−1. The expected mass-loading factor of the outflows, after accounting for multiphase gas, is ≳2 − 3, which is intermediate between AGN-driven and starburst-driven outflows. Hydrodynamic simulations in the literature predict that this pair will evolve to a luminous (M 1450 ≲ −26 mag), starbursting (≳1000 M ⊙ yr−1) quasar after coalescence, one of the most extreme populations in the early Universe.

DOI： 10.3847/1538-4357/ad57c6

Scopus

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-4357/ad46f9

researchmap

掲載種別：研究論文（学術雑誌）  

We investigated the gas obscuration and host galaxy properties of active galactic nuclei (AGNs) during the peak of cosmic accretion growth of supermassive black holes at redshift 0.8-1.8 using X-ray-detected AGNs with mid-infrared and far-infrared detection. The sample was classified as type-1 and type-2 AGNs using optical spectral and morphological classification while the host galaxy properties were estimated with multiwavelength spectral energy distribution fitting. For type-1 AGNs, the black hole mass was determined from MgII emission lines while the black hole mass of type-2 AGNs was inferred from the host galaxy's stellar mass. Based on the derived parameters, the distribution of the sample in the absorption hydrogen column density (NH) versus Eddington ratio diagram is examined. Among the type-2 AGNs, 28 ± 5 per cent are in the forbidden zone, where the obscuration by dust torus cannot be maintained due to radiation pressure on dusty material. The fraction is higher than that observed in the local universe from the Burst Alert Telescope AGN Spectroscopic Survey data release 2 (BASS DR2) (11 ± 3 per cent). The higher fraction implies that the obscuration of the majority of AGNs is consistent with the radiation pressure regulated unified model but with an increased incidence of interstellar matter (ISM)-obscured AGNs. We discuss the possibility of dust-free absorption in type-1 AGNs and heavy ISM absorption in type-2 AGNs. We also find no statistical difference in the star-formation activity between type-1 and type-2 AGNs which may suggest that obscuration triggered by a gas-rich merging is not common among X-ray detected AGNs in this epoch.

DOI： 10.1093/mnras/stae728

Scopus

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Abstract

We investigate the black hole mass function (BHMF) and Eddington-ratio distribution function (ERDF) of broad-line active galactic nuclei (AGNs) at z = 4, based on a sample of 52 quasars with i &lt; 23.2 at 3.50 ≤ z ≤ 4.25 from the Hyper Suprime-Cam Subaru Strategic Program S16A-Wide2 data set, and 1462 quasars with i &lt; 20.2 in the same redshift range from the Sloan Digital Sky Survey data release 7 quasar catalog. Virial black hole (BH) masses of quasars are estimated using the width of the C_IV 1549 Å line and the continuum luminosity at 1350 Å. To obtain the intrinsic broad-line AGN BHMF and ERDF, we correct for the incompleteness in the low-mass and/or low-Eddington-ratio ranges caused by the flux-limited selection. The resulting BHMF is constrained down to $\mathrm{log}{M}_{\mathrm{BH } }/{M}_{\odot }\sim 7.5$ . In comparison with broad-line AGN BHMFs at z ∼ 2 in the literature, we find that the number density of massive SMBHs peaks at higher redshifts, consistent with the downsizing evolutionary scenario. Additionally, the resulting ERDF shows a negative dependence on BH mass, suggesting more massive SMBHs tend to accrete at lower-Eddington ratios at z = 4. With the derived intrinsic broad-line AGN BHMF, we also evaluate the active fraction of broad-line AGNs among the entire SMBH population at z = 4. The resulting active fraction may suggest a positive dependence on BH mass. Finally, we examine the time evolution of broad-line AGN BHMF between z = 4 and 6 through solving the continuity equation. The results suggest that the broad-line AGN BHMFs at z = 4–6 only show evolution in their normalization, but with no significant changes in their shape.

DOI： 10.3847/1538-4357/ad1518

Scopus

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ad1518/pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Abstract

We report the distribution of black hole (BH) masses and Eddingont ratios estimated for a sample of 131 low luminosity quasars in the early cosmic epoch (5.6 &lt; z &lt; 7.0). Our work is based on the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which has constructed a low luminosity quasar sample down to M ₁₄₅₀ ∼ − 21 mag, exploiting the survey data of Hyper Suprime-Cam installed on Subaru Telescope. The discovery spectra of these quasars are limited to the rest-frame wavelengths of ∼1200–1400 Å, which contain no emission lines that can be used as BH mass estimators. In order to overcome this problem, we made use of low-z counterpart spectra from the Sloan Digital Sky Survey, which are spectrally matched to the high-z spectra in overlapping wavelengths. We then combined the C iv emission line widths of the counterparts with the continuum luminosity from the SHELLQs data to estimate BH masses. The resulting BH mass distribution has a range of ∼10^7–10 M _⊙, with most of the quasars having BH masses ∼10⁸ M _⊙ with sub-Eddington accretion. The present study provides not only a new insight into normal quasars in the reionization epoch, but also a new promising way to estimate BH masses of high-z quasars without near-infrared spectroscopy.

DOI： 10.3847/1538-4357/ad045e

Scopus

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ad045e/pdf

掲載種別：研究論文（国際会議プロシーディングス）  

In this paper, we present our approach regarding the compensation of defective pixels in the infrared array detector used in the NINJA spectrograph for the Subaru Telescope. While it is typical to use a detector with minimal defective pixels for infrared spectrographs, our HAWAII-2RG detector has a central area with a defective pixel rate of 10%. Therefore, we compensate for defective pixels by mechanically shifting the detector along the focal plane in the direction of dispersion. This approach applies the concept of dithering in imaging observation to a spectrograph, and the shifting mechanism is designed to have a maximum movement distance of 8 mm. We present the expected performance of the compensation and the actual mechanical structure fabricated.

DOI： 10.1117/12.3016873

Scopus

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Physical Society (APS)  

DOI： 10.1103/physrevd.108.063510

researchmap

その他リンク： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.108.063510/fulltext

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Abstract

The X-ray spectral state transitions of Galactic black hole transients (GBHTs) are often linked to the changes in the mass accretion rate. A narrow distribution of transition luminosity in terms of the Eddington ratio has been found in previous studies of GBHTs based on RXTE data (Maccarone, 2003, A&amp;A, 409, 697; Vahdat Motlagh et al., 2019, MNRAS, 485, 2744) and this Eddington ratio at the transition is often used in recent studies with instruments such as Swift/XRT and NICER/XTI, covering soft energies below 1 to 10 keV. However, the X-ray states characterized by spectral parameters may have different definitions depending on the energy ranges adopted in the spectral analysis, leaving the question of whether the distribution of transition luminosity obtained with RXTE remains the same when we use the instruments covering softer energy bands. In this work, we investigated the X-ray state evolutions and the variations of luminosities of eight outbursts of seven GBHTs. We found that the bolometric luminosity of the power-law component was tightly constrained to $\sim\! 1.3\%$ Eddington luminosity at index transition when the photon index starts to decrease towards the hard state, which is consistent with the previous RXTE results (Vahdat Motlagh et al. 2019, MNRAS, 485, 2744; Kalemci et al. 2013, ApJ, 779, 95). Moreover, the tightest clustering was found to be the power-law luminosity right after the start of disk recession, with a mean logarithmic Eddington ratio of −1.84 ± 0.28. In addition, our results suggest that the disk recession starts after the bolometric disk luminosity drops below 1% Eddington luminosity.

DOI： 10.1093/pasj/psad057

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-4357/ace43a

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：EDP Sciences  

We constructed the eROSITA X-ray catalog of radio galaxies discovered by the WERGS survey, made by cross-matching the wide area Subaru/Hyper Suprime-Cam (HSC) optical survey and VLA/FIRST 1.4 GHz radio survey. We report finding 393 eROSITA detected radio galaxies in the 0.5−2 keV band in the eFEDS field covering 140 deg². Thanks to the wide and medium depth eFEDS X-ray survey down to f_{0.5 − 2 keV} = 6.5 × 10⁻¹⁵ erg s⁻¹ cm⁻², the sample contains the rare and most X-ray luminous radio galaxies above the knee of the X-ray luminosity function, spanning 44 &lt; log(L_{0.5−2 keV}^(abs,corr)/erg s⁻¹) &lt; 46.5 at 1 &lt; z &lt; 4. The sample also contains the sources around and below the knee for the sources 41 &lt; log(L_{0.5−2 keV}^(abs,corr)/erg s⁻¹) &lt; 45 at z &lt; 1. Based on the X-ray properties obtained by the spectral fitting, 37 sources show obscured active galactic nucleus (AGN) signatures with log(N_H/cm⁻²) &gt; 22. These obscured and radio AGN reside in 0.4 &lt; z &lt; 3.2, indicating that they are obscured counterparts of the radio-loud quasar, which were missed in the previous optical quasar surveys. By combining radio and X-ray luminosities, we also investigated the jet production efficiency η_jet = η_radP_jet/L_AGN,bol by utilizing the jet power of P_jet. We find that there are 14 sources with extremely high jet production efficiency at η_jet ≈ 1. This high η_jet value might be a result of the decreased radiation efficiency of η_rad &lt; 0.1, due to the low accretion rate for those sources, and/or of the boosting due to the decline of L_AGN,bol by a factor of 10−100 by keeping P_jet constant in the previous Myr, indicating the experience of the AGN feedback. Finally, inferring the BH masses from the stellar mass, we find that X-ray luminous sources show the excess of the radio emission with respect to the value estimated from the fundamental plane. This radio emission excess cannot be explained by the Doppler boosting alone, and therefore the disk–jet connection of X-ray luminous eFEDS-WERGS is fundamentally different from the conventional fundamental plane which mainly covers the low-accretion regime.

DOI： 10.1051/0004-6361/202244271

Web of Science

researchmap

出版者・発行元：arXiv  

GREX-PLUS (Galaxy Reionization EXplorer and PLanetary Universe Spectrometer) is a mission candidate for a JAXA's strategic L-class mission to be launched in the 2030s. Its primary sciences are two-fold: galaxy formation and evolution and planetary system formation and evolution. The GREX-PLUS spacecraft will carry a 1.2 m primary mirror aperture telescope cooled down to 50 K. The two science instruments will be onboard: a wide-field camera in the 2-8 $μ$m wavelength band and a high resolution spectrometer with a wavelength resolution of 30,000 in the 10-18 $μ$m band. The GREX-PLUS wide-field camera aims to detect the first generation of galaxies at redshift $z&gt;15$. The GREX-PLUS high resolution spectrometer aims to identify the location of the water ``snow line'' in proto-planetary disks. Both instruments will provide unique data sets for a broad range of scientific topics including galaxy mass assembly, origin of supermassive blackholes, infrared background radiation, molecular spectroscopy in the interstellar medium, transit spectroscopy for exoplanet atmosphere, planetary atmosphere in the Solar system, and so on.

DOI： 10.48550/ARXIV.2304.08104

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Abstract

Statistical studies of X-ray selected active galactic nuclei (AGN) indicate that the fraction of obscured AGN increases with increasing redshift, and the results suggest that a significant part of the accretion growth occurs behind obscuring material in the early universe. We investigate the obscured fraction of highly accreting X-ray AGN at around the peak epoch of supermassive black hole growth utilizing the wide and deep X-ray and optical/IR imaging data sets. A unique sample of luminous X-ray selected AGNs above z &gt; 2 was constructed by matching the XMM-SERVS X-ray point-source catalog with a point-spread function convolved photometric catalog covering the u*–4.5 μm bands. Photometric redshift, hydrogen column density, and 2–10 keV AGN luminosity of the X-ray selected AGN candidates were estimated. Using the sample of 306 2–10 keV detected AGN at above redshift 2, we estimate the fraction of AGN with $\mathrm{log}{N}_{ { \rm{H } } }\ ({\mathrm{cm } }^{-2})\gt 22$ , assuming parametric X-ray luminosity and absorption functions. The results suggest that ${76}_{-3}^{+4} \% $ of luminous quasars ( $\mathrm{log}{L}_{X}\ (\mathrm{erg}\ { { \rm{s } } }^{-1})\gt 44.5$ ) above redshift 2 are obscured. The fraction indicates an increased contribution of obscured accretion at high redshift than that in the local universe. We discuss the implications of the increasing obscured fraction with increasing redshift based on the AGN obscuration scenarios, which describe obscuration properties in the local universe. Both the obscured and unobscured z &gt; 2 AGN show a broad range of SEDs and morphology, which may reflect the broad variety of host galaxy properties and physical processes associated with the obscuration.

DOI： 10.3847/1538-4357/ac9c07

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ac9c07/pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-4357/aca403

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Abstract

We present ionized gas properties of nine local ultra/luminous infrared galaxies (U/LIRGs) at z &amp;lt; 0.04 through Integral Field Unit (IFU) observations with KOOLS-IFU on the Seimei Telescope. The observed targets are drawn from the Great Observatories All-sky LIRG Survey (GOALS), covering a wide range of merger stages. We successfully detect emission lines such as Hβ, [O iii]λ5007, Hα, [N ii]λλ6549, 6583, and [S ii]λλ6717, 6731 with a spectral resolution of R = 1500–2000, which provides (i) a spatially resolved (∼200–700 pc) moment map of ionized gas and (ii) diagnostics for an active galactic nucleus (AGN) within the central ∼3–11 kpc in diameter for our sample. We find that the [O iii] outflow that is expected to be driven by an AGN tends to be stronger (i) towards the galactic center and (ii) as a sequence of the merger stage. In particular, the outflow strength in the late-stage (stage D) mergers is about 1.5 times stronger than that in the early-state (stage B) mergers, which indicates that galaxy mergers could induce AGN-driven outflow and play an important role in the co-evolution of galaxies and supermassive black holes.

DOI： 10.1093/pasj/psac073

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

ABSTRACT

Revealing the cosmic hydrogen reionization history is one of the main goals of the modern cosmology. z &amp;gt; 5 quasars (QSOs) have been used as back-lights to investigate the evolution of the intervening intergalactic medium (IGM) during the cosmic reionization since their first discovery. However, due to the small population of luminous QSOs (∼130 QSOs known to date), a tight constraint on the reionization history has not yet been placed. In this work, we aim to tighten the constraint using the 93 QSOs (5.5 &amp;lt; z &amp;lt; 7.1) recently discovered in the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQS) project. This is the largest QSO sample used to constrain the epoch of reionization. We measure the mean IGM Ly α transmission and the QSO near-zone size using the UV spectra of these QSOs. The mean IGM Ly α transmission rises above zero at z ≲ 6, indicating the end of the reionization. The near-zone sizes of the SHELLQs QSOs are consistent with sizes spanned by QSOs of lifetime tq ∼ 1–100 Myr in simulations. Due to the scatter created by the low signal-to-noise spectra and large Ly α redshift uncertainty, we cannot conclude whether the redshift evolution of the near-zone size is affected by the reionization effect.

DOI： 10.1093/mnras/stac2681

researchmap

その他リンク： https://academic.oup.com/mnras/article-pdf/517/1/1264/46441587/stac2681.pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Abstract

We report on the galaxy density environment around a high-z radio galaxy (HzRG) at z = 4.72, HSC J083913.17+011308.1 (HSC J0839+0113), probed using an r-dropout Lyman break galaxy (LBG) sample from the Hyper Suprime-Cam Subaru Strategic Program data. We find that HSC J0839+0113 resides in the outskirts of an overdense region identified by the r-dropout galaxies at a 4.7σ significance level. The projected distance between HSC J0839+0113 and the peak position of the overdense region is 0.4 physical Mpc, which is shorter than the typical protocluster radius in this epoch. According to the extended Press–Schechter and the light cone models, the HSC J0839+0113-hosted overdense region is expected to evolve into a halo &amp;gt;1014 ${M_{\odot } }$ at z = 0 with a high probability of $&amp;gt;\!\! 80\%$. These findings suggest that HSC J0839+0113 is associated with a protocluster. The HSC J0839+0113 rich-system is the most overdense region of LBGs among the known protoclusters with LBGs in the same cosmic epoch.

DOI： 10.1093/pasj/psac075

researchmap

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：SPIE  

DOI： 10.1117/12.2627749

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Abstract

The correlation between the mass of supermassive black holes (SMBHs; ${ { \mathcal M } }_{\mathrm{BH } }$ ) and their host galaxies ( ${ { \mathcal M } }_{\star }$ ) in the reionization epoch provides valuable constraints on their early growth. High-redshift quasars typically have an ${ { \mathcal M } }_{\mathrm{BH } }$ / ${ { \mathcal M } }_{\star }$ ratio significantly elevated in comparison to the local value. However, the degree to which this apparent offset is driven by observational biases is unclear for the most distant quasars. To address this issue, we model the sample selection and measurement biases for a compilation of 20 quasars at z ∼ 6 with host properties based on ALMA observations. We find that the observed distribution of quasars in the ${ { \mathcal M } }_{\mathrm{BH } }\mbox{--}{ { \mathcal M } }_{\star }$ plane can be reproduced by assuming that the underlying SMBH population at z ∼ 6 follows the relationship in the local universe. However, a positive or even a negative evolution in ${ { \mathcal M } }_{\mathrm{BH } }$ / ${ { \mathcal M } }_{\star }$ can also explain the data, depending on whether the intrinsic scatter evolves and on the strength of various systematic uncertainties. To break these degeneracies, an improvement in the accuracy of mass measurements and an expansion of the current sample to lower ${ { \mathcal M } }_{\mathrm{BH } }$ limits are needed. Furthermore, assuming a radiative efficiency of 0.1 and quasar duty cycles estimated from the active SMBH fraction, significant outliers in ${ { \mathcal M } }_{\mathrm{BH } }$ / ${ { \mathcal M } }_{\star }$ tend to move toward the local relation given their instantaneous BH growth rate and star formation rate. This may provide evidence for a self-regulated SMBH–galaxy coevolution scenario that is in place at z ∼ 6, with active galactic nucleus feedback being a possible driver.

DOI： 10.3847/2041-8213/ac6de8

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/2041-8213/ac6de8/pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1051/0004-6361/202141092

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Abstract

We estimate the amount of negative feedback energy injected into the interstellar medium (ISM) of the host galaxy of 3C 273, a prototypical radio-loud quasar. We obtained 93, 233, and 343 GHz continuum images with the Atacama Large Millimeter/submillimeter Array (ALMA). After self-calibration and point-source subtraction, we reach an image dynamic range of ∼85,000 at 93 GHz, ∼39,000 at 233 GHz, and ∼2500 at 343 GHz. These are currently the highest image dynamic range obtained using ALMA. We detect spatially extended millimeter emission associated with the host galaxy, cospatial with the extended emission line region (EELR) observed in the optical. The millimeter spectral energy distribution and comparison with centimeter data show that the extended emission cannot be explained by dust thermal emission or synchrotron or thermal bremsstrahlung arising from massive star formation. We interpret the extended millimeter emission as thermal bremsstrahlung from gas directly ionized by the central source. The extended flux indicates that at least ∼7% of the bolometric flux of the nuclear source was used to ionize atomic hydrogen in the host galaxy. The ionized gas is estimated to be as massive as 10¹⁰–10¹¹ M _⊙, but the molecular gas fraction with respect to the stellar mass is consistent with other ellipticals, suggesting that direct ionization ISM by the QSO may not be sufficient to suppress star formation, or we are witnessing a short timescale before negative feedback becomes observable. The discovery of a radio counterpart to EELRs provides a new pathway to studying the QSO–host ISM interaction.

DOI： 10.3847/1538-4357/ac616e

arXiv

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ac616e/pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Abstract

In this paper, we use high-quality rest-UV spectra of three radio galaxies at z ∼ 3 observed with the FORS2 camera on the Very Large Telescope to measure the flux of several emission lines, including relatively faint ones, such as N iv]λ1486, O iii]λ1663, and [Ne iv]λ2424. Additionally, we collect fluxes of faint rest-UV emission lines in 12 z ∼ 3 radio galaxies from the literature. Previously, physical and chemical properties of narrow-line regions (NLRs) in high-z active galactic nuclei (AGNs) have been investigated mostly by using only strong rest-UV emission lines (e.g., N v λ1240, C iv λ1549, He ii λ1640, and C iii]λ1909). Such strong-line diagnostics are based on various assumptions due to the limitation in the number of available emission-line constraints. In this work, both physical and chemical properties of NLR clouds in each object are estimated by fitting detailed photoionization models to the measured emission-line fluxes. We confirm that the metallicity of NLRs in AGNs at z ∼ 3 is solar or supersolar, without assumptions about the gas density and ionization parameter thanks to the constraints from the faint emission lines. This result suggests that high-z radio galaxies are already chemically mature at z ∼ 3.

DOI： 10.3847/1538-4357/ac5b71

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ac5b71/pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Abstract

We present new measurements of rest-UV luminosity functions and angular correlation functions from 4,100,221 galaxies at z ∼ 2–7 identified in the Subaru/Hyper Suprime-Cam survey and CFHT Large Area U-band Survey. The obtained luminosity functions at z ∼ 4–7 cover a very wide UV luminosity range of ∼ $0.002\mbox{--}2000{L}_{\mathrm{UV } }^{* }$ combined with previous studies, confirming that the dropout luminosity function is a superposition of the active galactic nucleus (AGN) luminosity function dominant at M _UV ≲ −24 mag and the galaxy luminosity function dominant at M _UV ≳ −22 mag, consistent with galaxy fractions based on 1037 spectroscopically identified sources. Galaxy luminosity functions estimated from the spectroscopic galaxy fractions show the bright-end excess beyond the Schechter function at ≳2σ levels, possibly made by inefficient mass quenching, low dust obscuration, and/or hidden AGN activity. By analyzing the correlation functions at z ∼ 2–6 with HOD models, we find a weak redshift evolution (within 0.3 dex) of the ratio of the star formation rate (SFR) to the dark matter accretion rate, $\mathrm{SFR}/{\dot{M } }_{ { \rm{h } } }$ , indicating the almost constant star formation efficiency at z ∼ 2–6, as suggested by our earlier work at z ∼ 4–7. Meanwhile, the ratio gradually increases with decreasing redshift at z &lt; 5 within 0.3 dex, which quantitatively reproduces the cosmic SFR density evolution, suggesting that the redshift evolution is primarily driven by the increase of the halo number density due to the structure formation, and the decrease of the accretion rate due to the cosmic expansion. Extrapolating this calculation to higher redshifts assuming the constant efficiency suggests a rapid decrease of the SFR density at z &gt; 10 with ∝ 10^−0.5(1+z), which will be directly tested with the James Webb Space Telescope.

DOI： 10.3847/1538-4365/ac3dfc

Scopus

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4365/ac3dfc/pdf

掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-4357/ac1b26

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ac1b26/pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-4357/abf6dc

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/abf6dc/pdf

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Abstract

We present Atacama Large Millimeter/submillimeter Array [C ii] 158 μm line and far-infrared (FIR) continuum emission observations toward HSC J120505.09−000027.9 (J1205−0000) at z = 6.72 with a beam size of ∼0.″8 × 0.″5 (or 4.1 kpc × 2.6 kpc), the most distant red quasar known to date. Red quasars are modestly reddened by dust and are thought to be in rapid transition from an obscured starburst to an unobscured normal quasar, driven by powerful active galactic nucleus (AGN) feedback that blows out a cocoon of interstellar medium. The FIR continuum of J1205−0000 is bright, with an estimated luminosity of L_FIR ∼ 3 × 10¹²L_⊙. The [C ii] line emission is extended on scales of r ∼ 5 kpc, greater than that of the FIR continuum. The line profiles at the extended regions are complex and broad (FWHM ∼ 630–780 km s⁻¹). Although it is not practical to identify the nature of this extended structure, possible explanations include (i) companion/merging galaxies and (ii) massive AGN-driven outflows. For the case of (i), the companions are modestly star-forming (∼10 M_⊙ yr⁻¹) but are not detected by our Subaru optical observations (y_AB,5σ = 24.4 mag). For the case of (ii), our lower limit to the cold neutral outflow rate is ∼100 M_⊙ yr⁻¹. The outflow kinetic energy and momentum are both much lower than predicted in energy-conserving wind models, suggesting that the AGN feedback in this quasar is not capable of completely suppressing its star formation.

DOI： 10.3847/1538-4357/abd7ef

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/abd7ef/pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-4357/abc47b

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-4357/abbe11

Web of Science

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/abbe11

掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-4357/abb80b

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/abb80b

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-4357/aba4a3

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/aba4a3

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

<title>Abstract</title>
We present the first discovery of dust-reddened quasars (red quasars) in the high-z universe (z &amp;gt; 5.6). This is a result from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which is based on the sensitive multi-band optical imaging data produced by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. We identified four red quasar candidates from the 93 spectroscopically confirmed high-z quasars in the SHELLQs sample, based on detections in the Wide-field Infrared Survey Explorer (WISE) data at 3.4 and 4.6 μm (rest-frame ∼5000–6500 Å). The amount of dust reddening was estimated with spectral energy distribution (SED) fits over optical and mid-infrared wavelengths. Two of the four candidates were found to be red quasars with dust reddening of E(B − V) &amp;gt; 0.1. The remaining SHELLQs quasars without individual WISE detections are significantly fainter in the WISE bands and bluer than the red quasars, although we did detect them in the W1 band in a stacked image. We also conducted the same SED fits for high-z optically-luminous quasars, but no red quasar was found. This demonstrates the power of Subaru HSC to discover high-z red quasars, which are fainter than the limiting magnitudes of past surveys in the rest-frame ultraviolet, due to dust extinction.

DOI： 10.1093/pasj/psaa074

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

<title>Abstract</title>
Active galactic nuclei (AGNs) are key in understanding the coevolution of galaxies and supermassive black holes (SMBHs). AGN activity is thought to affect the properties of their host galaxies via a process called “AGN feedback,” which drives the coevolution. From a parent sample of 1151 z &amp;lt; 1 type-1 quasars from the Sloan Digital Sky Survey quasar catalog, we detected the host galaxies of 862 of them in the high-quality grizy images of the Subaru Hyper Suprime-Cam survey. The unprecedented combination of the survey area and depth allowed us to perform a statistical analysis of the quasar host galaxies, with small sample variance. We fitted the radial image profile of each quasar as a linear combination of the point spread function and the Sérsic function, decomposing the images into the quasar nucleus and the host galaxy components. We found that the host galaxies are massive, with stellar mass Mstar ≳ 1010 $M_\odot$, and are mainly located on the green valley. This trend is consistent with a scenario in which star formation in the host galaxies is suppressed by AGN feedback, that is, AGN activity may be responsible for the transition of these galaxies from the blue cloud to the red sequence. We also investigated the SMBH mass to stellar mass relation of the z &amp;lt; 1 quasars, and found a consistent slope with the local relation, while the SMBHs may be slightly undermassive. However, the above results are subject to our sample selection, which biases against host galaxies with low masses and/or large quasar-to-host flux ratios.

DOI： 10.1093/pasj/psaa072

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-3881/ab98fe

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-3881/ab98fe

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We present our new Atacama Large Millimeter/Submillimeter Array (ALMA) observations targeting [O iii]88 μm, [C ii]158 μm, [N ii]122 μm, and dust-continuum emission for three Lyman break galaxies at z = 6.0293-6.2037, identified in the Subaru/Hyper Suprime-Cam survey. We clearly detect [O iii] and [C ii] lines from all of the galaxies at 4.3-11.8σ levels, and identify multi-band dust-continuum emission in two of the three galaxies, allowing us to estimate infrared luminosities and dust temperatures simultaneously. In conjunction with previous ALMA observations for six galaxies at z > 6, we confirm that all the nine z = 6-9 galaxies have high [O iii]/[C ii] ratios of, ∼10 times higher than z ∼ 0 galaxies. We also find a positive correlation between the [O iii]/[C ii] ratio and the Lyα equivalent width (EW) at the ∼90% significance level. We carefully investigate physical origins of the high [O iii]/[C ii] ratios at z = 6-9 using Cloudy, and find that high density of the interstellar medium, low C/O abundance ratio, and the cosmic microwave background attenuation are responsible to only a part of the z = 6-9 galaxies. Instead, the observed high [O iii]/[C ii] ratios are explained by 10-100 times higher ionization parameters or low photodissociation region (PDR) covering fractions of 0%-10%, both of which are consistent with our [N ii] observations. The latter scenario can be reproduced with a density-bounded nebula with PDR deficit, which would enhance the Lyα, Lyman continuum, and C+ ionizing photons escape from galaxies, consistent with the [O iii]/[C ii]-Lyα EW correlation we find.

DOI： 10.3847/1538-4357/ab94bd

Scopus

arXiv

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ab94bd

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We study variability of active galactic nuclei (AGNs) by using the deep optical multiband photometry data obtained from the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP) survey in the COSMOS field. The images analyzed here were taken with 8, 10, 13, and 15 epochs over three years in the g, r, i, and z bands, respectively. We identified 491 robust variable AGN candidates, down to i = 25 mag and with redshift up to 4.26. Ninety percent of the variability-selected AGNs are individually identified with the X-ray sources detected in the Chandra COSMOS Legacy survey. We investigate their properties in variability by using structure function analysis and find that the structure function for low-luminosity AGNs (L-bol less than or similar to 10(45) erg s(-1)) shows a positive correlation with luminosity, which is the opposite trend for the luminous quasars. This trend is likely to be caused by a larger contribution of the host galaxy light for lower-luminosity AGNs. Using the model templates of galaxy spectra, we evaluate the amount of host galaxy contribution to the structure function analysis and find that dominance of the young stellar population is needed to explain the observed luminosity dependence. This suggests that low-luminosity AGNs at 0.8 less than or similar to z less than or similar to 1.8 are predominantly hosted in star-forming galaxies. The X-ray stacking analysis reveals the significant emission from the individually X-ray undetected AGNs in our variability-selected sample. The stacked samples show very large hardness ratios in their stacked X-ray spectrum, which suggests that these optically variable sources have large soft X-ray absorption by dust-free gas.

DOI： 10.3847/1538-4357/ab83f3

Web of Science

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ab83f3

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

<title>Abstract</title>
We present ALMA [C ii] line and far-infrared (FIR) continuum observations of three $z \gt 6$ low-luminosity quasars ($M_{\rm 1450} \gt -25$ mag) discovered by our Subaru Hyper Suprime-Cam (HSC) survey. The [C ii] line was detected in all three targets with luminosities of $(2.4\mbox{--}9.5) \times 10^8\, L_{\odot }$, about one order of magnitude smaller than optically luminous ($M_{\rm 1450} \lesssim -25$ mag) quasars. The FIR continuum luminosities range from $\lt 9 \times 10^{10}\, L_{\odot }$ (3 $\sigma$ limit) to ${\sim } 2 \times 10^{12}\, L_{\odot }$, indicating a wide range in star formation rates in these galaxies. Most of the HSC quasars studied thus far show [C ii]/ FIR luminosity ratios similar to local star-forming galaxies. Using the [C ii]-based dynamical mass ($M_{\rm dyn}$) as a surrogate for bulge stellar mass ($M_{\rm\, bulge}$), we find that a significant fraction of low-luminosity quasars are located on or even below the local $M_{\rm\, BH}$–$M_{\rm\, bulge}$ relation, particularly at the massive end of the galaxy mass distribution. In contrast, previous studies of optically luminous quasars have found that black holes are overmassive relative to the local relation. Given the low luminosities of our targets, we are exploring the nature of the early co-evolution of supermassive black holes and their hosts in a less biased way. Almost all of the quasars presented in this work are growing their black hole mass at a much higher pace at $z \sim 6$ than the parallel growth model, in which supermassive black holes and their hosts grow simultaneously to match the local $M_{\rm\, BH}$–$M_{\rm\, bulge}$ relation at all redshifts. As the low-luminosity quasars appear to realize the local co-evolutionary relation even at $z \sim 6$, they should have experienced vigorous starbursts prior to the currently observed quasar phase to catch up with the relation.

DOI： 10.1093/pasj/psz096

arXiv

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

<title>Abstract</title>
This paper presents the second data release of the Hyper Suprime-Cam Subaru Strategic Program, a wide-field optical imaging survey using the 8.2 m Subaru Telescope. The release includes data from 174 nights of observation through 2018 January. The Wide layer data cover about 300 deg$^2$ in all five broad-band filters ($grizy$) to the nominal survey exposure (10 min in $gr$ and 20 min in $izy$). Partially observed areas are also included in the release; about 1100 deg$^2$ is observed in at least one filter and one exposure. The median seeing in the i-band is ${0_{.}^{\prime \prime }6}$, demonstrating the superb image quality of the survey. The Deep (26 deg$^2$) and UltraDeep (4 deg$^2$) data are jointly processed and the UltraDeep-COSMOS field reaches an unprecedented depth of $i\sim 28$ at $5 \, \sigma$ for point sources. In addition to the broad-band data, narrow-band data are also available in the Deep and UltraDeep fields. This release includes a major update to the processing pipeline, including improved sky subtraction, PSF modeling, object detection, and artifact rejection. The overall data quality has been improved, but this release is not without problems; there is a persistent deblender problem as well as new issues with masks around bright stars. The user is encouraged to review the issue list before utilizing the data for scientific explorations. All the image products as well as catalog products are available for download. The catalogs are also loaded into a database, which provides an easy interface for users to retrieve data for objects of interest. In addition to these main data products, detailed galaxy shape measurements withheld from Public Data Release 1 (PDR1) are now available to the community. The shape catalog is drawn from the S16A internal release, which has a larger area than PDR1 (160 deg$^2$). All products are available at the data release site, https://hsc-release.mtk.nao.ac.jp/.

DOI： 10.1093/pasj/psz103

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-4357/ab2cd5

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ab2cd5

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-4357/ab29e9

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ab29e9

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We present physical properties of radio galaxies (RGs) with f(1.4) GHz > 1 mJy discovered by Subaru Hyper Suprime-Cam (HSC) and Very Large Array Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. For 1056 FIRST RGs at 0 < z <= 1.7 with HSC counterparts in about 100 deg(2), we compiled multi-wavelength data of optical, near-infrared (IR), mid-IR, far-IR, and radio (150 MHz). We derived their color excess (E(B - V)(*)), stellar mass, star formation rate (SFR), IR luminosity, the ratio of IR and radio luminosity (q(IR)), and radio spectral index (alpha(radio)) that are derived from the spectral energy distribution (SED) fitting with CIGALE. We also estimated Eddington ratio based on stellar mass and integration of the best-fit SEDs of active galactic nucleus (AGN) component. We found that E(B - V)(*), SFR, and IR luminosity clearly depend on redshift while stellar mass, q(IR), and alpha(radio) do not significantly depend on redshift. Since optically faint (i(AB) >= 21.3) RGs that are newly discovered by our RG survey tend to be high redshift, they tend to not only have a large dust extinction and low stellar mass but also have high SFR and AGN luminosity, high IR luminosity, and high Eddington ratio compared with optically bright ones. The physical properties of a fraction of RGs in our sample seem to differ from a classical view of RGs with massive stellar mass, low SFR, and low Eddington ratio, demonstrating that our RG survey with HSC and FIRST provides us curious RGs among entire RG population.

DOI： 10.3847/1538-4365/ab238d

Web of Science

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4365/ab238d

掲載種別：研究論文（学術雑誌）   出版者・発行元：Cambridge University Press (CUP)  

<title>Abstract</title>We present ALMA [CII] line and far-infrared (FIR) continuum observations of seven <italic>z</italic> &gt; 6 low-luminosity quasars (<italic>M</italic>₁₄₅₀ &gt; −25 mag) discovered by our on-going Subaru Hyper Suprime-Cam survey. The [CII] line was detected in all targets with luminosities of ∼(2−10) × 10⁸ L_⊙, about one order of magnitude smaller than optically luminous quasars. Also found was a wide scatter of FIR continuum luminosity, ranging from <italic>L</italic>_FIR &lt; 10¹¹<italic>L</italic>_⊙ to ∼2 × 10¹²<italic>L</italic>_⊙. With the [CII]-based dynamical mass, we suggest that a significant fraction of low-luminosity quasars are located on or even below the local Magorrian relation, particularly at the massive end of the galaxy mass distribution. This is a clear contrast to the previous finding that luminous quasars tend to have overmassive black holes relative to the relation. Our result is expected to show a less-biased nature of the early co-evolution of black holes and their host galaxies.

DOI： 10.1017/s1743921319009487

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-4357/ab1754

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/1538-4357/ab1754

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-4357/aaf1a7

researchmap

その他リンク： http://stacks.iop.org/0004-637X/870/i=2/a=118?key=crossref.d99e4583bd59d1aaee1fa2de0ceddc3b

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We report the result of optical identifications of FIRST radio sources with the Hyper Suprime-Cam Subaru Strategic Program survey (HSC-SSP). The positional cross-match within 1 '' between the FIRST and HSC-SSP catalogs (i less than or similar to 26) produced more than 3600 optical counterparts in the 156 deg(2) of the HSC-SSP field. The matched counterparts account for more than 50% of the FIRST sources in the search field, which substantially exceed previously reported fractions of SDSS counterparts (i less than or similar to 22) of -30%. Among the matched sample, 9% are optically unresolved sources such as radio-loud quasars. The optically faint (i > 21) radio galaxies (RGs) show that the fitting linear function of the 1.4 GHz source counts has a slope that is flatter than that of the bright RGs, while optically faint radio quasars show a slope steeper than that of bright radio quasars. The optically faint RGs show a flat slope in the i-band number counts down to 24 mag, implying either less massive or distant radio-active galactic nuclei (AGNs) beyond 24 mag. The photometric redshift and the comparison of colors with the galaxy models show that most of the matched RGs are distributed at redshifts from 0 to 1.5. The optically faint sample includes the high radio-loudness sources that are not seen in the optically bright sample. Such sources are located at redshift z > 1. This study gives similar to 1500 radio AGNs lying at the optically faint end and high-redshift regime not probed by previous searches.

DOI： 10.3847/1538-4357/aae1ac

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/866/i=2/a=140?key=crossref.0ec0e513a9a68350c7a7b8af8d48eb8a

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1093/mnras/sty1394

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-3881/aad0f0

researchmap

その他リンク： http://stacks.iop.org/1538-3881/156/i=3/a=86?key=crossref.746f26c24c0fe299b9db16ac8107c7b3

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Association for the Advancement of Science (AAAS)  

Previous detections of individual astrophysical sources of neutrinos are limited to the Sun and the supernova 1987A, whereas the origins of the diffuse flux of high-energy cosmic neutrinos remain unidentified. On 22 September 2017, we detected a high-energy neutrino, IceCube-170922A, with an energy of ~290 tera–electron volts. Its arrival direction was consistent with the location of a known γ-ray blazar, TXS 0506+056, observed to be in a flaring state. An extensive multiwavelength campaign followed, ranging from radio frequencies to γ-rays. These observations characterize the variability and energetics of the blazar and include the detection of TXS 0506+056 in very-high-energy γ-rays. This observation of a neutrino in spatial coincidence with a γ-ray–emitting blazar during an active phase suggests that blazars may be a source of high-energy neutrinos.

DOI： 10.1126/science.aat1378

Scopus

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1093/pasj/psy026

arXiv

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-4357/aabd80

Scopus

researchmap

その他リンク： http://stacks.iop.org/0004-637X/859/i=2/a=84?key=crossref.7ac188c26ec6690da4dea9a2fa59d02d

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1093/mnras/sty1344

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layered imaging survey aimed at addressing some of the most important outstanding questions in astronomy today, including the nature of dark matter and dark energy. The survey has been awarded 300 nights of observing time at the Subaru Telescope, and it started in 2014 March. This paper presents the first public data release of HSC-SSP. This release includes data taken in the first 1.7 yr of observations (61.5 nights), and each of the Wide, Deep, and UltraDeep layers covers about 108, 26, and 4 square degrees down to depths of i similar to 26.4, similar to 26.5, and similar to 27.0 mag, respectively (5 sigma for point sources). All the layers are observed in five broad bands (grizy), and the Deep and UltraDeep layers are observed in narrow bands as well. We achieve an impressive image quality of 0.'' 6 in the i band in the Wide layer. We show that we achieve 1%-2% point spread function (PSF) photometry (root mean square) both internally and externally (against Pan-STARRS1), and similar to 10 mas and 40 mas internal and external astrometric accuracy, respectively. Both the calibrated images and catalogs are made available to the community through dedicated user interfaces and database servers. In addition to the pipeline products, we also provide value-added products such as photometric redshifts and a collection of public spectro-scopic redshifts. Detailed descriptions of all the data can be found online. The data release website is https://hsc-release.mtk.nao.ac.jp.

DOI： 10.1093/pasj/psx081

Web of Science

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg(2) in five broad bands (grizy), with a 5 sigma point-source depth of r approximate to 26. The Deep layer covers a total of 26 deg(2) in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg(2)). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey.

DOI： 10.1093/pasj/psx066

Web of Science

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

We present the luminosity function of z similar to 4 quasars based on the Hyper Suprime-Cam Subaru Strategic Program Wide layer imaging data in the g, r, i, z, and y bands covering 339.8 deg(2). From stellar objects, 1666 z similar to 4 quasar candidates are selected via the g-dropout selection down to i = 24.0 mag. Their photometric redshifts cover the red-shift range between 3.6 and 4.3, with an average of 3.9. In combination with the quasar sample from the Sloan Digital Sky Survey in the same redshift range, a quasar luminosity function covering the wide luminosity range of M-1450 = -22 to -29 mag is constructed. The quasar luminosity function is well described by a double power-law model with a knee at M-1450 = -25.36 +/- 0.13mag and a flat faint-end slope with a power-law index of -1.30 +/- 0.05. The knee and faint-end slope show no clear evidence of redshift evolution from those seen at z similar to 2. The flat slope implies that the UV luminosity density of the quasar population is dominated by the quasars around the knee, and does not support the steeper faint-end slope at higher redshifts reported at z > 5. If we convert the M-1450 luminosity function to the hard X-ray 2-10 keV luminosity function using the relation between the UV and X-ray luminosity of quasars and its scatter, the number density of UV-selected quasars matches well with that of the X-ray-selected active galactic nuclei (AGNs) above the knee of the luminosity function. Below the knee, the UV-selected quasars show a deficiency compared to the hard X-ray luminosity function. The deficiency can be explained by the lack of obscured AGNs among the UV-selected quasars.

DOI： 10.1093/pasj/psx091

Web of Science

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

We study the UV luminosity functions (LFs) at z similar to 4, 5, 6, and 7 based on the deep large-area optical images taken by the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP). On the 100 deg(2) sky of the HSC SSP data available to date, we take enormous samples consisting of a total of 579565 dropout candidates at z similar to 4-7 by the standard color selection technique, 358 out of which are spectroscopically confirmed by our follow-up spectroscopy and other studies. We obtain UV LFs at z similar to 4-7 that span a very wide UV luminosity range of similar to 0.002-100 L*(UV) (-26 < M-UV < -14 mag) by combining LFs from our program and the ultra-deep Hubble Space Telescope legacy surveys. We derive three parameters of the best-fit Schechter function, phi*, M*(UV), and alpha, of the UV LFs in the magnitude range where the active galactic nucleus (AGN) contribution is negligible, and find that a and f* decrease from z similar to 4 to 7 with no significant evolution of M*(UV). Because our HSC SSP data bridge the LFs of galaxies and AGNs with great statistical accuracy, we carefully investigate the bright end of the galaxy UV LFs that are estimated by the subtraction of the AGN contribution either aided by spectroscopy or the best-fit AGN UV LFs. We find that the bright end of the galaxy UV LFs cannot be explained by the Schechter function fits at > 2 sigma significance, and require either double power-law functions or modified Schechter functions that consider a magnification bias due to gravitational lensing.

DOI： 10.1093/pasj/psx103

Web of Science

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

` We investigate the galaxy overdensity around proto-cluster scale quasar pairs at high (z > 3) and low (z similar to 1) redshift based on the unprecedentedly wide and deep optical survey of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). Using the first-year survey data covering effectively similar to 121 deg(2) with the 5 sigma depth of i similar to 26.4 and the SDSS DR12Q catalog, we find two luminous pairs at z similar to 3.3 and 3.6 which reside in > 5s overdensity regions of g-dropout galaxies at i < 25. The projected separations of the two pairs are R-perpendicular to = 1.75 and 1.04 proper Mpc (pMpc), and their velocity offsets are Delta V = 692 and 1448 kms(-1), respectively. This result is in clear contrast to the average z similar to 4 quasar environments as discussed in Uchiyama et al. (2018, PASJ 70, S32) and implies that the quasar activities of the pair members are triggered via major mergers in proto-clusters, unlike the vast majority of isolated quasars in general fields that may turn on via non-merger events such as bar and disk instabilities. At z similar to 1, we find 37 pairs with R-perpendicular to < 2 pMpc and Delta V < 2300 kms(-1) in the current HSC-Wide coverage, including four from Hennawi et al. (2006, AJ, 131, 1). The distribution of the peak overdensity significance within two arcminutes around the pairs has a long tail toward high-density (>4 sigma) regions. Thanks to the large sample size, we find statistical evidence that this excess is unique to the pair environments when compared to single-quasar and randomly selected galaxy environments at the same redshift range. Moreover, there are nine small-scale (R-perpendicular to < 1 pMpc) pairs, two of which are found to reside in cluster fields. Our results demonstrate that <2 pMpc scale quasar pairs at both redshift ranges tend to occur in massive haloes, although perhaps not the most massive ones, and that they are useful in searching for rare density peaks.

DOI： 10.1093/pasj/psx092

Web of Science

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

We examine the clustering of quasars over a wide luminosity range, by utilizing 901 quasars at (Z) over bar (phot) similar to 3.8 with -24.73 < M-1450 < -22.23 photometrically selected from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) S16A Wide2 date release and 342 more luminous quasars at 3.4 < z(spec) < 4.6 with -28.0 < M-1450 < -23.95 from the Sloan Digital Sky Survey that fall in the HSC survey fields. We measure the bias factors of two quasar samples by evaluating the cross-correlation functions (CCFs) between the quasar samples and 25790 bright z similar to 4 Lyman break galaxies in M-1450 < -21.25 photometrically selected from the HSC dataset. Over an angular scale of 10".0 to 1000".0, the bias factors are 5.93(-1.43)(+1.34) and 2.73(-2.55)(+2.44) for the low-and high-luminosity quasars, respectively, indicating no significant luminosity dependence of quasar clustering at z similar to 4. It is noted that the bias factor of the luminous quasars estimated by the CCF is smaller than that estimated by the auto-correlation function over a similar redshift range, especially on scales below 40".0. Moreover, the bias factor of the less-luminous quasars implies the minimal mass of their host dark matter halos is 0.3-2 x 10(12) h(-1)M(circle dot), corresponding to a quasar duty cycle of 0.001-0.06.

DOI： 10.1093/pasj/psx129

Web of Science

Scopus

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1093/pasj/psx135

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We constrain the quasar contribution to the cosmic reionization based on our deep optical survey of z similar to 6 quasars down to z(R) = 24.15 using Subaru/Suprime-Cam in three UKIDSS-DXS fields covering 6.5 deg(2). In Kashikawa et al. (2015), we select 17 quasar candidates and report our initial discovery of two low-luminosity quasars (M-1450 similar to -23) from seven targets, one of which might be a Ly alpha-emitting galaxy. From an additional optical spectroscopy, none of the four candidates out of the remaining 10 turn out to be genuine quasars. Moreover, the deeper optical photometry provided by the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) shows that, unlike the two already-known quasars, the i - z and z - y colors of the last six candidates are consistent with M-or L-type brown dwarfs. Therefore, the quasar luminosity function (QLF) measurement in the previous paper is confirmed. Compiling the QLF measurements from the literature over a wide magnitude range, including an extremely faint AGN candidate from Parsa et al. (2017), to fit them with a double power law, we find that the bestfit faint-end slope is alpha = -2.04(-0.18)(+0.33) (-1.98(-0.18)(+0.48)) and characteristic magnitude is M-1450* = -25.8(-1.9)(+1.1) (-25.7(-1.8)(+1.0)) in the case of two (one) quasar detection. Our result suggests that, if the QLF is integrated down to M1450 = -18, quasars produce similar to 1%-12% of the ionizing photons required to fully ionize the universe at z similar to 6 with a 2 sigma confidence level, assuming that the escape fraction is f(esc) = 1 and the intergalactic medium clumpy factor is C = 3. Even when the systematic uncertainties are taken into account, our result supports the scenario that quasars are the minor contributors of the reionization.

DOI： 10.3847/2041-8213/aa8cc6

Web of Science

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/2041-8213/aa8cc6

掲載種別：研究論文（学術雑誌）   出版者・発行元：Frontiers Media SA  

DOI： 10.3389/fspas.2017.00015

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/2041-8213/aa78f8

Web of Science

researchmap

その他リンク： https://iopscience.iop.org/article/10.3847/2041-8213/aa78f8

掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-4357/aa72f0

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/841/i=2/a=128?key=crossref.73acc3deb2d5e20b7b14274f5d75a6ad

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1093/pasj/psx003

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：The Korean Astronomical Society  

DOI： 10.5303/pkas.2017.32.1.157

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

We report the serendipitous discovery of a quadruply lensed source at z(s) = 3.76, HSC J115252+004733, from the Hyper Suprime-Cam (HSC) Survey. The source is lensed by an early-type galaxy at z(1) = 0.466 and a satellite galaxy. Here, we investigate the properties of the source by studying its size and luminosity from the imaging and the luminosity and velocity width of the Ly-alpha line from the spectrum. Our analyses suggest that the source is most probably a low-luminosity active galactic nucleus (LLAGN) but the possibility of it being a compact bright galaxy (e.g. a Lyman-alpha emitter or lyman break galaxy) cannot be excluded. The brighter pair of lensed images appears point-like except in the HSC i band (with a seeing similar to 0.5 arcsec). The extended emission in the i-band image could be due to the host galaxy underneath the AGN, or alternatively, due to a highly compact lensed galaxy (without AGN) which appears point-like in all bands except in i band. We also find that the flux ratio of the brighter pair of images is different in the Ks band compared to optical wavelengths. Phenomena such as differential extinction and intrinsic variability cannot explain this chromatic variation. While microlensing from stars in the foreground galaxy is less likely to be the cause, it cannot be ruled out completely. If the galaxy hosts an AGN, then this represents the highest redshift quadruply imaged AGN known to date, enabling study of a distant LLAGN. Discovery of this unusually compact and faint source demonstrates the potential of the HSC survey.

DOI： 10.1093/mnras/stw2924

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

We present measurements of the clustering properties of a sample of infrared (IR) bright dust-obscured galaxies (DOGs). Combining 125 deg(2) of wide and deep optical images obtained with the Hyper Suprime-Cam on the Subaru Telescope and all-sky mid-IR images taken with Wide-Field Infrared Survey Explorer, we have discovered 4367 IR-bright DOGs with (i - [22])(AB) > 7.0 and flux density at 22 mu m > 1.0 mJy. We calculate the angular autocorrelation function (ACF) for a uniform subsample of 1411 DOGs with 3.0 mJy < flux (22 mu m) < 5.0 mJy and i(AB) < 24.0. The ACF of our DOG subsample is well-fit with a single power law, w(theta) = (0.010 +/- 0.003)theta(-0.9), where theta is in degrees. The correlation amplitude of IR-bright DOGs is larger than that of IR-faint DOGs, which reflects a flux dependence of the DOG clustering, as suggested by Brodwin et al. We assume that the redshift distribution for our DOG sample is Gaussian, and consider two cases: (1) the redshift distribution is the same as IR-faint DOGs with flux at 22 mu m < 1.0 mJy, mean and sigma z = 1.99 +/- 0.45, and (2) z = 1.19 +/- 0.30, as inferred from their photometric redshifts. The inferred correlation length of IR-bright DOGs is r(0) = 12.0 +/- 2.0 and 10.3 +/- 1.7 h(-1) Mpc, respectively. IR-bright DOGs reside in massive dark matter halos with a mass of log [ M-h /(h(-1) M-circle dot)] = 13.57(-0.55)(+0.50) and 13.65(-0.52)(+0.45) in the two cases, respectively.

DOI： 10.3847/1538-4357/835/1/36

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/835/i=1/a=36?key=crossref.8bc97fbf94353d8ba653ca76249fa940

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Recent large-scale infrared surveys have been revealing stellar populations in the inner Galaxy seen through strong interstellar extinction in the disc. In particular, classical Cepheids with their period-luminosity and period-age relations are useful tracers of Galactic structure and evolution. Interesting groups of Cepheids reported recently include four Cepheids in the nuclear stellar disc (NSD), about 200 pc around the Galactic Centre, found by Matsunaga et al. and those spread across the inner part of the disc reported by Dekany and collaborators. We here report our discovery of nearly 30 classical Cepheids towards the bulge region, some of which are common with Dekany et al., and discuss the large impact of the reddening correction on distance estimates for these objects. Assuming that the four Cepheids in the NSD are located at the distance of the Galactic Centre and that the near-infrared extinction law, i.e. wavelength dependency of the interstellar extinction, is not systematically different between the NSD and other bulge lines of sight, most of the other Cepheids presented here are located significantly further than the Galactic Centre. This suggests a lack of Cepheids in the inner 2.5 kpc region of the Galactic disc except the NSD. Recent radio observations show a similar distribution of star-forming regions.

DOI： 10.1093/mnras/stw1548

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

We explore the effect of varying the mass of a seed black hole on the resulting black hole massbulge mass relation at z similar to 0, using a semi-analytic model of galaxy formation combined with large cosmological N-body simulations. We constrain our model by requiring that the observed properties of galaxies at z similar to 0 are reproduced. In keeping with previous semi-analytic models, we place a seed black hole immediately after a galaxy forms. When the mass of the seed is set at 10(5)M(circle dot), we find that the model results become inconsistent with recent observational results of the black hole mass-bulge mass relation for dwarf galaxies. In particular, the model predicts that bulges with similar to 10(9)M(circle dot) harbour larger black holes than observed. On the other hand, when we employ seed black holes of 10(3)M(circle dot) or select their mass randomly within a 10(3)-5M(circle dot) range, the resulting relation is consistent with observation estimates, including the observed dispersion. We find that, to obtain stronger constraints on the mass of seed black holes, observations of less massive bulges at z similar to 0 are a more powerful comparison than the relations at higher redshifts.

DOI： 10.1093/mnras/stw1798

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

Using all-sky maps obtained from the Cosmic Background Explorer/Diffuse Infrared Background Experiment (DIRBE) at 3.5 and 4.9 mu m, we present a reanalysis of diffuse sky emissions such as zodiacal light (ZL), diffuse Galactic light (DGL), integrated starlight (ISL), and isotropic residual emission including the extragalactic background light (EBL). Our new analysis, which includes an improved estimate of ISL using the Wide-field Infrared Survey Explorer data, enabled us to find the DGL signal in a direct linear correlation between diffuse near-infrared and 100 mu m emission at high Galactic latitudes (vertical bar b vertical bar > 35 degrees). At 3.5 mu m, the high-latitude DGL result is comparable to the low-latitude value derived from the previous DIRBE analysis. In comparison with models of the DGL spectrum assuming a size distribution of dust grains composed of amorphous silicate, graphite, and polycyclic aromatic hydrocarbon (PAH), the measured DGL values at 3.5 and 4.9 mu m constrain the mass fraction of PAH particles in the total dust species to be more than similar to 2%. This was consistent with the results of Spitzer/IRAC toward the lower Galactic latitude regions. The derived residual emission of 8.9 +/- 3.4 nWm(-2) sr(-1) at 3.5 mu m is marginally consistent with the level of integrated galaxy light and the EBL constraints from the gamma-ray observations. The residual emission at 4.9 mu m is not significantly detected due to the large uncertainty in the ZL subtraction, the same as in previous studies. Combined with our reanalysis of the DIRBE data at 1.25 and 2.2 mu m, the residual emission in the near-infrared exhibits the Rayleigh-Jeans spectrum.

DOI： 10.3847/0004-637x/818/1/72

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/818/i=1/a=72?key=crossref.8d01065a633b08a1c67a64b525c65e4e

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1093/pasj/psv057

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

Using all-sky maps obtained with COBE/DIRBE, we reanalyzed the diffuse sky brightness at 1.25 and 2.2 mu m, which consists of zodiacal light, diffuse Galactic light (DGL), integrated starlight (ISL), and isotropic emission including the extragalactic background light. Our new analysis including an improved estimate of the DGL and the ISL with the 2MASS data showed that deviations of the isotropic emission from isotropy were less than 10% in the entire sky at high Galactic latitude (vertical bar b vertical bar > 35 degrees). We derived the DGL to 100 mu m brightness ratios of similar to 4.79 and similar to 1.49 n W m(-2) MJy(-1) at 1.25 and 2.2 mu m, respectively. The result of our analysis revealed a significantly large isotropic component at 1.25 and 2.2 mu m with intensities of 60.15 +/- 16.14 and 27.68 +/- 6.21 n W m(-2) sr(-1), respectively. This intensity is larger than the integrated galaxy light, upper limits from gamma-ray observation, and potential contribution from exotic sources (i.e., Population III stars, intrahalo light, direct collapse black holes, and dark stars). We therefore conclude that the excess light may originate from the local universe: the Milky Way and/or the solar system.

DOI： 10.1088/0004-637x/811/2/77

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/811/i=2/a=77?key=crossref.1f22d47f1203425253708f644a58a7df

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-637x/789/1/91

Scopus

researchmap

その他リンク： http://stacks.iop.org/0004-637X/789/i=1/a=91?key=crossref.6578a247b1cec0fb340902f9d394e9df

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-637x/767/1/80

Web of Science

researchmap

その他リンク： http://stacks.iop.org/0004-637X/767/i=1/a=80?key=crossref.e711cc16d83f3434f91bf8be3102ff1d

掲載種別：研究論文（学術雑誌）   出版者・発行元：EDP Sciences  

DOI： 10.1051/0004-6361/201220451

Web of Science

researchmap

記述言語：英語  

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-6256/144/4/112

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：The Korean Astronomical Society  

DOI： 10.5303/pkas.2012.27.4.353

researchmap

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：AIP  

DOI： 10.1063/1.4754369

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：SPIE  

WISH, Wide-field Imaging Surveyor for High-redshiftt, is a space mission concept to conduct very deep and wide-field surveys at near infrared wavelength at 1-5 mu m to study the properties of galaxies at very high redshift beyond the epoch of cosmic reionization. The concept has been developed and studied since 2008 to be proposed for future JAXA/ISAS mission. WISH has a 1.5m-diameter primary mirror and a wide-field imager covering 850 arcmin(2) The pixel scale is 0.155 arcsec for 18 mu m pitch, which properly samples the diffraction-limited image at 1.5 mu m. The main program is Ultra Deep Survey (UDS) covering 100 deg(2) down to 28AB mag at least in five broad bands We expect to detect >10(4) galaxies at z=8-9, 10(3)-10(4) galaxies at z=11-12, and 50-100 galaxies at z>14, many of which can be feasible targets for deep spectroscopy with Extremely Large Telescopes. With recurrent deep observations, detection and light curve monitoring for type-Ia SNe in rest-frame infrared wavelength is also conducted, which is another main science goal of the mission. During the in-orbit 5 years observations, we expect to detect and monitor >2000 type-Ia SNe up to z similar to 2. WISH also conducts Ultra Wide Survey, covering 1000deg(2) down to 24-25AB mag as well as Extreme Survey, covering a limited number of fields of view down to 29-30AB mag. We here report the progress of the WISH project including the basic telescope and satellite design as well as the results of the test for a proto-model of the flip-type filter exchanger which works robustly near 100K.

DOI： 10.1117/12.925632

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-637x/741/1/22

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Cambridge University Press (CUP)  

<title>Abstract</title>We present the new constraints on the cosmic optical background (COB) obtained from an analysis of the <italic>Pioneer 10/11</italic> Imaging Photopolarimeter (IPP) data. After careful examination of data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (~0.44 μm) and red (~0.64 μm) bands. Accurate starlight subtraction is achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with thermal 100 μm brightness, while another betrays a constant level in the lowest 100 μm brightness region. Presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has the extragalactic origin (i.e., the COB). The derived COB brightness is (1.8 ± 0.9) × 10⁻⁹ and (1.2 ± 0.9) × 10⁻⁹ erg s⁻¹ cm⁻² sr⁻¹ Å⁻¹ at the blue and red band, respectively, or 7.9 ± 4.0 and 7.7 ± 5.8 nW m⁻² sr⁻¹. Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions of other populations including “first stars” at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL)---scattered starlight by the interstellar dust. We derive the mean DGL-to-100 μm brightness ratios of 2.1 × 10⁻³ and 4.6 × 10⁻³ at the two bands, which are roughly consistent with the previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.

DOI： 10.1017/s1743921312009581

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1111/j.1365-2966.2010.17960.x

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1111/j.1365-2966.2010.17498.x

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：SPIE  

WISH is a new space science mission concept whose primary goal is to study the first galaxies in the early universe. We will launch a 1.5m telescope equipped with 1000 arcmin(2) wide-field NIR camera by late 2010's in order to conduct unique ultra-deep and wide-area sky surveys at 1-5 micron. The primary science goal of WISH mission is pushing the high-redshift frontier beyond the epoch of reionization by utilizing its unique imaging capability and the dedicated survey strategy. We expect to detect similar to 10(4) galaxies at z=8-9, similar to 3-6x10(3) galaxies at z=11-12, and similar to 50-100 galaxies at z=14-17 within about 5 years of the planned mission life time. It is worth mentioning that a large fraction of these objects may be bright enough for the spectroscopic observations with the extremely large telescopes. By adopting the optimized strategy for the recurrent observations to reach the depth, we also use the surveys to detect transient objects. Type Ia Supernova cosmology is thus another important primary goal of WISH. A unique optical layout has been developed to achieve the diffraction-limited imaging at 1-5micron over the required large area. Cooling the mirror and telescope to similar to 100K is needed to achieve the zodiacal light limited imaging and WISH will achieve the required temperature by passive cooling in the stable thermal environment at the orbit near Sun-Earth L2. We are conducting the conceptual studies and development for the important components of WISH including the exchange mechanism for the wide-field filters as well as the primary mirror fixation.

DOI： 10.1117/12.856561

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Blackwell Publishing  

We present the detailed optical to far-infrared (far-IR) observations of SST J1604+4304, an ultraluminous IR galaxy at z = 1.135. Analysing the stellar absorption lines, namely, the Ca II H & K and Balmer H lines in the optical spectrum, we derive the upper limits of an age for the stellar population. Given this constraint, the minimum χ2 method is used to fit the stellar population models to the observed spectral energy distribution from 0.44 to 5.8 μm. We find the following properties. The stellar population has an age 40-200 Myr with a metallicity 2.5 Z⊙. The starlight is reddened by E(B - V) = 0.8. The reddening is caused by the foreground dust screen, indicating that dust is depleted in the starburst site and the starburst site is surrounded by a dust shell. The IR (8-1000 μm) luminosity is L_[ir] = 1.78 ± 0.63 x 10^[12] L⊙. This is two times greater than that expected from the observed starlight, suggesting either that 1/2 of the starburst site is completely obscured at UV-optical wavelengths, or that 1/2 of L_[ir] comes from active galactic nucleus (AGN) emission. The inferred dust mass is 2.0 ± 1.0 x 10^[8] M⊙. This is sufficient to form a shell surrounding the galaxy with an optical depth E(B - V) = 0.8. From our best stellar population model - an instantaneous starburst with an age 40 Myr - we infer the rate of 19 supernovae per year. Simply analytical models imply that 2.5 Z⊙ in stars was reached when the gas mass reduced to 30 per cent of the galaxy mass. The gas metallcity is 4.8 Z⊙ at this point. The gas-to-dust mass ratio is then 120 ± 73. The inferred dust production rate is 0.24 ± 0.12 M⊙ per SN. If 1/2 of L_[ir] comes from AGN emission, the rate is 0.48 ± 0.24 M⊙ per SN. We discuss the evolutionary link of SST J1604+4304 to other galaxy populations in terms of the stellar masses and the galactic winds, including optically selected low-luminosity Lyman α-emitters and submillimeter selected high-luminosity galaxies.

DOI： 10.1111/j.1365-2966.2009.15873.x

Web of Science

researchmap

掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：EDP Sciences  

DOI： 10.1051/spica/200904018

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1088/0004-637x/697/1/452

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1111/j.1365-2966.2009.14605.x

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ASTRONOMICAL SOC PACIFIC  

We present rest-frame optical/near-infrared spectra of the gravitationally lensed quasar APM 08279+5255 at z = 3.91 that has been taken using the Infrared Camera (IRC) onboard the AKARI infrared satellite. The observed continuum consists of two components; a power-law component dominating optical wavelengths which is the direct light from the central source and thermal emission dominating near-infrared wavelengths which is attributed to the emission from hot dust in the circumnuclear region. The thermal emission well represents optically thick emission by hot dust at T similar to 1300K with T-2 mu m &gt; 2. Thus, our observations directly detected the optically thick region of hot dust in APM 08279+5255. HI recombination lines of H alpha(0.656 mu m), Pa alpha(1.875 mu m), and Pa beta(1.282 mu m) are clearly detected at 3.2, 6.3, and 9.3 mu m. Simulations with the photoionization models suggest that APM 08279+5255 has BLR(Broad Line Region) clouds characterized by log nH similar to 12 - 14 for the gas density, log U similar to -2- - 6 for the ionization parameter, and E(B - V) similar to 0.3 - 0.6 for the broad line region. Thus, optically thick emission of hot dust support an idea on non-spherical distribution of dust near the central source, consistent with the Active Galactic Nuclei model with the dust torus.

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ASTRONOMICAL SOC PACIFIC  

We are carrying out a program to explore prominent Fe IT emission-line regions in AGNs with near-infrared (NIR) O I and Ca II lines is tracers. To date we have observed and compiled the relevant O I (lambda 1304, lambda 8446, and lambda 11287) and Ca IT (lambda 8579 triplet) lines in 11 quasars at 0.06 &lt;= z &lt;= 1.08. he comparison with photoionization model calculations suggests that gas with a density n(H) = 10(11.5) 10(12.0) cm(-3) is present in in outer portion of the broad emission-line region (BELR) illuminated by the ionizing radiation whose flux corresponds to the ionization parameter U = 10(-3.0) 10(-2.5) on average. While the revealed gas density is similar, the ionizing radiation flux appears to be diverse among the quasars.

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SOC ITALIANA FISICA  

We are carrying on a. program to explore the prominent Fe II line emission regions in Active Galactic Nuclei (AGNs) with near-IR, O I and Ca II lines as tracers. To date we have observed and compiled in 11 quasars the relevant O I and Ca It lines, i.e. the strongest three O I lines in AGNs (lambda 1304, lambda 8446, and lambda 11287) and Ca II lambda 8579 triplet. The quasars are distributed over wide ranges of redshift (0.06 &lt;= z &lt;= 1.08) and of luminosity (-29.8 &lt;= z &lt;= -22.1), thus representing a useful sample to investigate the line emission regions in various quasar environments. The photoionization model calculations were performed and compared with the observations. It suggests that a rather dense gas with density n(H) = 10(11.5)-11(12.0) cm(-3) is present; at an outer portion of the Broad Emission Line Region (BELR), illuminated by the ionizing radiation whose flux corresponds to the ionization parameter U = 10(-3.0)-10(-2.5) on average. While the revealed gas density is similar, the ionizing radiation flux appears to be diverse among the quasars. In line with the line strength arguments; the observed O 1 line widths are remarkably similar over snore than 3 orders of magnitude in luminosity, which indicates a kinematically determined location of the emission region and is in clear contrast to the well-studied case of the H I lines.

DOI： 10.1393/ncb/i2008-10471-4

Web of Science

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

DOI： 10.1111/j.1745-3933.2006.00252.x

Web of Science

researchmap

記述言語：英語  

researchmap

掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing  

DOI： 10.1086/506376

Web of Science

researchmap

記述言語：英語  

researchmap

記述言語：英語  

researchmap

researchmap

researchmap

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

会議種別：口頭発表（招待・特別）  

researchmap

会議種別：口頭発表（招待・特別）  

researchmap

会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（招待・特別）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：日本語   会議種別：口頭発表（招待・特別）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

researchmap

会議種別：口頭発表（一般）  

researchmap

会議種別：公開講演，セミナー，チュートリアル，講習，講義等  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：口頭発表（一般）  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

記述言語：英語   会議種別：ポスター発表  

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap

researchmap