189 results on '"Yoshiki MATSUOKA"'
Search Results
2. Discovery of Merging Twin Quasars at z = 6.05
- Author
-
Yoshiki Matsuoka, Takuma Izumi, Masafusa Onoue, Michael A. Strauss, Kazushi Iwasawa, Nobunari Kashikawa, Masayuki Akiyama, Kentaro Aoki, Junya Arita, Masatoshi Imanishi, Rikako Ishimoto, Toshihiro Kawaguchi, Kotaro Kohno, Chien-Hsiu Lee, Tohru Nagao, John D. Silverman, and Yoshiki Toba
- Subjects
Double quasars ,Quasars ,Reionization ,High-redshift galaxies ,Active galactic nuclei ,Galaxy mergers ,Astrophysics ,QB460-466 - Abstract
We report the discovery of two quasars at a redshift of z = 6.05 in the process of merging. They were serendipitously discovered from the deep multiband imaging data collected by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. The quasars, HSC J121503.42−014858.7 (C1) and HSC J121503.55−014859.3 (C2), both have luminous (>10 ^43 erg s ^−1 ) Ly α emission with a clear broad component (full width at half maximum >1000 km s ^−1 ). The rest-frame ultraviolet (UV) absolute magnitudes are M _1450 = − 23.106 ± 0.017 (C1) and −22.662 ± 0.024 (C2). Our crude estimates of the black hole masses provide $\mathrm{log}({M}_{\mathrm{BH}}/{M}_{\odot })=8.1\pm 0.3$ in both sources. The two quasars are separated by 12 kpc in projected proper distance, bridged by a structure in the rest-UV light suggesting that they are undergoing a merger. This pair is one of the most distant merging quasars reported to date, providing crucial insight into galaxy and black hole build-up in the hierarchical structure formation scenario. A companion paper will present the gas and dust properties captured by Atacama Large Millimeter/submillimeter Array observations, which provide additional evidence for and detailed measurements of the merger, and also demonstrate that the two sources are not gravitationally lensed images of a single quasar.
- Published
- 2024
- Full Text
- View/download PDF
3. Merging Gas-rich Galaxies That Harbor Low-luminosity Twin Quasars at z = 6.05: A Promising Progenitor of the Most Luminous Quasars
- Author
-
Takuma Izumi, Yoshiki Matsuoka, Masafusa Onoue, Michael A. Strauss, Hideki Umehata, John D. Silverman, Tohru Nagao, Masatoshi Imanishi, Kotaro Kohno, Yoshiki Toba, Kazushi Iwasawa, Kouichiro Nakanishi, Mahoshi Sawamura, Seiji Fujimoto, Satoshi Kikuta, Toshihiro Kawaguchi, Kentaro Aoki, and Tomotsugu Goto
- Subjects
Galaxy evolution ,Quasars ,Galaxy mergers ,Galaxy interactions ,Astrophysics ,QB460-466 - Abstract
We present Atacama Large Millimeter/submillimeter Array [C ii ] 158 μ m 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 × 10 ^9 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 ∼10 ^11 M _⊙ . The dynamical masses of the two galaxies are large (∼9 × 10 ^10 M _⊙ for C1 and ∼5 × 10 ^10 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.
- Published
- 2024
- Full Text
- View/download PDF
4. Environments around Quasars at z ∼ 3 Revealed by Wide-field Imaging with Subaru HSC and CFHT
- Author
-
Yuta Suzuki, Hisakazu Uchiyama, Yoshiki Matsuoka, Jun Toshikawa, Stephen Gwyn, Masatoshi Imanishi, Chengze Liu, Akatoki Noboriguchi, Marcin Sawicki, and Yoshiki Toba
- Subjects
Quasars ,Galaxy environments ,Astrophysics ,QB460-466 - Abstract
We examine the local density environments around 67 quasars at z ∼ 3 by combining the imaging data of Hyper Suprime-Cam Subaru Strategic Program and Canada–France–Hawaii Telescope Large Area U -band Deep Survey over about 20 deg ^2 . Our measurements exploit U -dropout galaxies in the vicinities of quasars taken from the Sloan Digital Sky Survey. We find that the quasars have an indistinguishable surrounding density distribution from the U -dropout galaxies and that three quasars are associated with protocluster candidates within a projected separation of 3′. According to a halo evolutionary model, our results suggest that quasars at this epoch occupy haloes with a typical mass of ${1.3}_{-0.9}^{+1.4}\times {10}^{13}{h}^{-1}{{M}}_{\odot }$ . We also investigate the dependence of the local galaxy overdensity on ultraviolet (UV) luminosities, black hole masses, and proximity zone sizes of the quasars, but no statistically significant correlation was found. Finally, we find that the local density of faint U -dropout galaxies are lower than that of bright U -dropout galaxies within a projected distance of 0.51 ± 0.05 physical Mpc, where the quasar UV radiation is 30 times more intense than background UV radiation. We argue that photoevaporation may suppress galaxy formation at short distances where the quasar UV intensity is strong, even in massive haloes.
- Published
- 2024
- Full Text
- View/download PDF
5. Reconstruction of Cosmic Black Hole Growth and Mass Distribution from Quasar Luminosity Functions at z > 4: Implications for Faint and Low-mass Populations in JWST
- Author
-
Wenxiu Li, Kohei Inayoshi, Masafusa Onoue, Wanqiu He, Yoshiki Matsuoka, Zhiwei Pan, Masayuki Akiyama, Takuma Izumi, and Tohru Nagao
- Subjects
High-redshift galaxies ,Quasars ,Supermassive black holes ,Astrophysics ,QB460-466 - Abstract
The evolution of the quasar luminosity function (QLF) is fundamental to understanding the cosmic evolution of black holes (BHs) through their accretion phases. In the era of the James Webb Space Telescope (JWST), Euclid, and Nancy Grace Roman Space Telescope, their unprecedented detection sensitivity and wide survey area can unveil the low-luminosity quasar and low-mass BH population, and provide new insights into quasar host galaxies. We present a theoretical model describing BH growth from initial seeding at z ≳ 20 to ∼ 4, incorporating the duration of accretion episodes, the distribution of Eddington ratios, and the mass dependency of BH accretion rates. By constraining the model parameters with the observed QLFs at 4 ≤ z ≤ 6 across a wide UV luminosity range, we find that the high-redshift BH population grows rapidly at z ≳ 6, and decelerates the pace in subsequent epochs. Toward lower redshifts ( z < 6), mass-dependent accretion inhibits the growth of high-mass BHs with M _• > 10 ^8 M _⊙ , leading to mass saturation at M _• ≳ 10 ^10 M _⊙ . We predict the BH mass function down to M _• ∼ 10 ^6 M _⊙ for both unobscured and obscured quasar populations at 4 ≤ z ≤ 11, offering a benchmark for future observational tests. Our model accounts for the presence of both bright and faint quasars at z > 4, including those discovered by JWST. Furthermore, our findings suggest two distinct pathways for the early assembly of the BH–galaxy mass correlation: the population with a BH-to-stellar-mass ratio near the local value of M _• / M _⋆ ≃ 5 × 10 ^−3 maintains proximity to the relation via moderate growth, while the population that begins to grow above the local relation becomes as overmassive as M _• / M _⋆ ∼ 0.01–0.1 by z ∼ 6 via rapid mass accretion.
- Published
- 2024
- Full Text
- View/download PDF
6. The Relationship of Supermassive Black Holes and Host Galaxies at z < 4 in the Deep Optical Variability-selected Active Galactic Nuclei Sample in the COSMOS Field
- Author
-
Atsushi Hoshi, Toru Yamada, Mitsuru Kokubo, Yoshiki Matsuoka, and Tohru Nagao
- Subjects
Active galactic nuclei ,Supermassive black holes ,Black hole physics ,Seyfert galaxies ,Astrophysics ,QB460-466 - Abstract
We present the study on the relationship between supermassive black holes (SMBHs) and their host galaxies using our variability-selected active galactic nuclei (AGNs) sample ( i _AB ≤ 25.9 and z ≤ 4.5) constructed from the Hyper Suprime-Cam Subaru Strategic Program Ultradeep survey in the COSMOS field. We estimated the black hole (BH) mass ( M _BH = 10 ^5.5−10 M _⊙ ) based on the single-epoch virial method and the total stellar mass ( M _star = 10 ^10−12 M _⊙ ) by separating the AGN component with spectral energy distribution fitting. We found that the redshift evolution of the BH–stellar mass ratio ( M _BH / M _star ) depends on the M _BH , which is caused by no significant correlation between M _BH and M _star . Variable AGNs with massive SMBHs ( M _BH > 10 ^9 M _⊙ ) at 1.5 < z < 3 show considerably higher BH–stellar mass ratios (> ∼1%) than the BH–bulge ratios ( M _BH / M _bulge ) observed in the local Universe for the same BH range. This implies that there is a typical growth path of massive SMBHs, which is faster than the formation of the bulge component as final products seen in the present day. For the low-mass SMBHs ( M _BH < 10 ^8 M _⊙ ) at 0.5 < z < 3, on the other hand, variable AGNs show similar BH–stellar mass ratios with the local objects (∼0.1%), but smaller than those observed at z > 4. We interpret that host galaxies harboring less massive SMBHs at intermediate redshift have already acquired sufficient stellar mass, although high- z galaxies are still in the early stage of galaxy formation relative to those at the intermediate/local Universe.
- Published
- 2024
- Full Text
- View/download PDF
7. Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XVII. Black Hole Mass Distribution at z ∼ 6 Estimated via Spectral Comparison with Low-z Quasars
- Author
-
Ayumi Takahashi, Yoshiki Matsuoka, Masafusa Onoue, Michael A. Strauss, Nobunari Kashikawa, Yoshiki Toba, Kazushi Iwasawa, Masatoshi Imanishi, Masayuki Akiyama, Toshihiro Kawaguchi, Akatoki Noboriguchi, and Chien-Hsiu Lee
- Subjects
Quasars ,Supermassive black holes ,Reionization ,Astrophysics ,QB460-466 - 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 < z < 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 ∼10 ^8 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.
- Published
- 2024
- Full Text
- View/download PDF
8. Black Hole Mass and Eddington-ratio Distributions of Less-luminous Quasars at z ∼ 4 in the Subaru Hyper Suprime-Cam Wide Field
- Author
-
Wanqiu He, Masayuki Akiyama, Motohiro Enoki, Kohei Ichikawa, Kohei Inayoshi, Nobunari Kashikawa, Toshihiro Kawaguchi, Yoshiki Matsuoka, Tohru Nagao, Masafusa Onoue, Taira Oogi, Andreas Schulze, Yoshiki Toba, and Yoshihiro Ueda
- Subjects
Supermassive black holes ,Galaxy evolution ,High-redshift galaxies ,Active galaxies ,Astrophysics ,QB460-466 - 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 < 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 < 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.
- Published
- 2024
- Full Text
- View/download PDF
9. Quasar Luminosity Function at z = 7
- Author
-
Yoshiki Matsuoka, Masafusa Onoue, Kazushi Iwasawa, Michael A. Strauss, Nobunari Kashikawa, Takuma Izumi, Tohru Nagao, Masatoshi Imanishi, Masayuki Akiyama, John D. Silverman, Naoko Asami, James Bosch, Hisanori Furusawa, Tomotsugu Goto, James E. Gunn, Yuichi Harikane, Hiroyuki Ikeda, Kohei Inayoshi, Rikako Ishimoto, Toshihiro Kawaguchi, Satoshi Kikuta, Kotaro Kohno, Yutaka Komiyama, Chien-Hsiu Lee, Robert H. Lupton, Takeo Minezaki, Satoshi Miyazaki, Hitoshi Murayama, Atsushi J. Nishizawa, Masamune Oguri, Yoshiaki Ono, Taira Oogi, Masami Ouchi, Paul A. Price, Hiroaki Sameshima, Naoshi Sugiyama, Philip J. Tait, Masahiro Takada, Ayumi Takahashi, Tadafumi Takata, Masayuki Tanaka, Yoshiki Toba, Shiang-Yu Wang, and Takuji Yamashita
- Subjects
Supermassive black holes ,Quasars ,Reionization ,Astrophysics ,QB460-466 - Abstract
We present the quasar luminosity function (LF) at z = 7, measured with 35 spectroscopically confirmed quasars at 6.55 < z < 7.15. The sample of 22 quasars from the Subaru High- z Exploration of Low-Luminosity Quasars (SHELLQs) project, combined with 13 brighter quasars in the literature, covers an unprecedentedly wide range of rest-frame ultraviolet magnitudes over −28 < M _1450 < −23. We found that the binned LF flattens significantly toward the faint end populated by the SHELLQs quasars. A maximum likelihood fit to a double power-law model has a break magnitude ${M}_{1450}^{* }=-{25.60}_{-0.30}^{+0.40}$ , a characteristic density ${{\rm{\Phi }}}^{* }={1.35}_{-0.30}^{+0.47}$ Gpc ^−3 mag ^−1 , and a bright-end slope $\beta =-{3.34}_{-0.57}^{+0.49}$ , when the faint-end slope is fixed to α = −1.2 as observed at z ≤ 6. The overall LF shape remains remarkably similar from z = 4 to 7, while the amplitude decreases substantially toward higher redshifts, with a clear indication of an accelerating decline at z ≥ 6. The estimated ionizing photon density, 10 ^48.2±0.1 s ^−1 Mpc ^−3 , is less than 1% of the critical rate to keep the intergalactic medium ionized at z = 7, and thus indicates that quasars are not a major contributor to cosmic reionization.
- Published
- 2023
- Full Text
- View/download PDF
10. Multilineage Lymphoblastic Lymphoma as an Initial Presentation of Mixed Phenotype Acute Leukemia
- Author
-
Mako Ikeda, Wataru Nakahara, Mizuki Asako, Yuka Umeki, Yoshiki Matsuoka, Takuya Terakawa, Hitomi Matsunaga, Yuki Iwasa, Riko Saito, Yuki Iwama, Takahiro Matsui, Kazumasa Oka, and Shuji Ueda
- Subjects
Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
Mixed phenotype acute leukemia (MPAL) is characterized by leukemic blasts that express markers of multiple lineages. Compared with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), MPAL is considered to have a poor treatment outcome. We report a case of MPAL T/myeloid not otherwise specified that was initially presented as multilineage lymphoblastic lymphoma and subsequently developed into leukemic MPAL. An acute lymphoblastic leukemia-based treatment regimen was ineffective, but azacitidine and venetoclax therapy resulted in hematological complete remission. Our case suggests that multilineage lymphoblastic lymphoma should be considered to be the same disease as MPAL, albeit with different clinical presentations. Optimal treatment for MPAL has not been established yet, but azacitidine and venetoclax therapy may be a potential approach.
- Published
- 2023
- Full Text
- View/download PDF
11. Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XVIII. The Dark Matter Halo Mass of Quasars at z ∼ 6
- Author
-
Junya Arita, Nobunari Kashikawa, Yoshiki Matsuoka, Wanqiu He, Kei Ito, Yongming Liang, Rikako Ishimoto, Takehiro Yoshioka, Yoshihiro Takeda, Kazushi Iwasawa, Masafusa Onoue, Yoshiki Toba, and Masatoshi Imanishi
- Subjects
Large-scale structure of the universe ,Quasars ,Supermassive black holes ,Astrophysics ,QB460-466 - Abstract
We present, for the first time, dark matter halo (DMH) mass measurement of quasars at z ∼ 6 based on a clustering analysis of 107 quasars. Spectroscopically identified quasars are homogeneously extracted from the Hyper Suprime-Cam Strategic Survey Program wide layer over 891 deg ^2 . We evaluate the clustering strength by three different autocorrelation functions: projected correlation function, angular correlation function, and redshift–space correlation function. The DMH mass of quasars at z ∼ 6 is evaluated as ${5.0}_{-4.0}^{+7.4}\times {10}^{12}\,{h}^{-1}{M}_{\odot }$ with the bias parameter b = 20.8 ± 8.7 by the projected correlation function. The other two estimators agree with these values; though, each uncertainty is large. The DMH mass of quasars is found to be nearly constant ∼10 ^12.5 h ^−1 M _⊙ throughout cosmic time, suggesting that there is a characteristic DMH mass where quasars are always activated. As a result, quasars appear in the most massive halos at z ∼ 6, but in less extreme halos thereafter. The DMH mass does not appear to exceed the upper limit of 10 ^13 h ^−1 M _⊙ , which suggests that most quasars reside in DMHs with ${M}_{\mathrm{halo}}\lt {10}^{13}{h}^{-1}{M}_{\odot }$ across most of the cosmic time. Our results supporting a significant increasing bias with redshift are consistent with the bias evolution model with inefficient active galactic nucleus feedback at z ∼ 6. The duty cycle ( f _duty ) is estimated as 0.019 ± 0.008 by assuming that DMHs in some mass interval can host a quasar. The average stellar mass is evaluated from stellar-to-halo mass ratio as ${M}_{* }={6.5}_{-5.2}^{+9.6}\times {10}^{10}\,{h}^{-1}{M}_{\odot }$ , which is found to be consistent with [C ii ] observational results.
- Published
- 2023
- Full Text
- View/download PDF
12. Theoretical Re-evaluations of Scaling Relations between SMBHs and Their Host Galaxies—1. Effect of Seed BH Mass
- Author
-
Hikari Shirakata, Toshihiro Kawaguchi, Takashi Okamoto, Ryu Makiya, Tomoaki Ishiyama, Yoshiki Matsuoka, Masahiro Nagashima, Motohiro Enoki, Taira Oogi, and Masakazu A. R. Kobayashi
- Subjects
galaxies ,active galactic nuclei ,bulge ,galaxy formation ,statistics ,Astronomy ,QB1-991 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
We use a semi-analytic model of galaxy formation and investigate how the mass of a seed black hole affect the scaling relation between black hole mass and bulge mass at z ~ 0. When the mass of the seed is set at 105M⊙, we find that the model results become inconsistent with recent observational results of the scaling relation for dwarf galaxies. On the other hand, when we set seed black hole mass as 103M⊙ or as randomly chosen value within a 103-5M⊙ range, we find the results are consistent with observational results including the dispersion. We also find that black hole mass—bulge mass relations for less massive bulges at z ~ 0 put stronger constraints on the seed BH mass than the relations at higher redshifts.
- Published
- 2017
- Full Text
- View/download PDF
13. A 6.4Gbps/pin NAND Flash Memory Multi-Chip Package Employing a Frequency Multiplying Bridge Chip for Scalable Performance and Capacity Storage Systems.
- Author
-
Shinichi Ikeda, Akira Iwata, Goichi Otomo, Tomoaki Suzuki, Hiroaki Iijima, Mikio Shiraishi, Shinya Kawakami, Masatomo Eimitsu, Yoshiki Matsuoka, Kiyohito Sato, Shigehiro Tsuchiya, Yoshinori Shigeta, and Takuma Aoyama
- Published
- 2023
- Full Text
- View/download PDF
14. Anomalous diffusion in a randomly modulated velocity field.
- Author
-
Noriaki Aibara, Naoaki Fujimoto, So Katagiri, Yutaka Matsuo, Yoshiki Matsuoka, Akio Sugamoto, Ken Yokoyama, and Tsukasa Yumibayashi
- Published
- 2023
- Full Text
- View/download PDF
15. Optical IFU observations of GOALS sample with KOOLS-IFU on Seimei Telescope: Initial results of nine U/LIRGs at z < 0.04
- Author
-
Yoshiki Toba, Satoshi Yamada, Kazuya Matsubayashi, Koki Terao, Aoi Moriya, Yoshihiro Ueda, Kouji Ohta, Aoi Hashiguchi, Kazuharu G Himoto, Hideyuki Izumiura, Kazuma Joh, Nanako Kato, Shuhei Koyama, Hiroyuki Maehara, Rana Misato, Akatoki Noboriguchi, Shoji Ogawa, Naomi Ota, Mio Shibata, Nozomu Tamada, Anri Yanagawa, Naoki Yonekura, Tohru Nagao, Masayuki Akiyama, Masaru Kajisawa, and Yoshiki Matsuoka
- Subjects
Space and Planetary Science ,Astronomy and Astrophysics - Abstract
We present ionized gas properties of nine local ultra/luminous infrared galaxies (U/LIRGs) at z < 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.
- Published
- 2022
16. Subaru Hyper Suprime-Cam view of quasar host galaxies at z < 1
- Author
-
Toru Ishino, Yoshiki Matsuoka, Shuhei Koyama, Yuya Saeda, Michael A Strauss, Andy D Goulding, Masatoshi Imanishi, Toshihiro Kawaguchi, Takeo Minezaki, Tohru Nagao, Akatoki Noboriguchi, Malte Schramm, John D Silverman, Yoshiaki Taniguchi, and Yoshiki Toba
- Published
- 2020
- Full Text
- View/download PDF
17. Imaging extended emission-line regions of obscured AGN with the Subaru Hyper Suprime-Cam Survey
- Author
-
Ai-Lei Sun, Jenny E Greene, Nadia L Zakamska, Andy D Goulding, Michael A Strauss, Song Huang, Sean D Johnson, Toshihiro Kawaguchi, Yoshiki Matsuoka, Alisabeth A Marsteller, Tohru Nagao, and Yoshiki Toba
- Published
- 2018
- Full Text
- View/download PDF
18. Determinants of the COVID-19 Vaccination among the Medical Workers
- Author
-
Shohei KATSUNO, Fumihiro KOBAYASHI, Makiko SHIBANO, and Yoshiki MATSUOKA
- Subjects
Epidemiology - Published
- 2022
19. eROSITA Final Equatorial-Depth Survey (eFEDS): eFEDS X-ray view of WERGS Radio Galaxies selected by the Subaru/HSC and VLA/FIRST survey
- Author
-
Kohei Ichikawa, Takuji Yamashita, Andrea Merloni, Junyao Li, Teng Liu, Mara Salvato, Masayuki Akiyama, Riccardo Arcodia, Tom Dwelly, Xiaoyang Chen, Masatoshi Imanishi, Kohei Inayoshi, Toshihiro Kawaguchi, Taiki Kawamuro, Mitsuru Kokubo, Yoshiki Matsuoka, Tohru Nagao, Malte Schramm, Hyewon Suh, Masayuki Tanaka, Yoshiki Toba, and Yoshihiro Ueda
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Astrophysics of Galaxies - Abstract
We construct the eROSITA X-ray catalog of radio galaxies discovered by the WERGS survey that is made by the cross-matching of the wide-area Subaru/HSC optical survey and VLA/FIRST 1.4 GHz radio survey. We find 393 eROSITA detected radio galaxies in the 0.5--2 keV band in the eFEDS field covering 140~deg$^2$. Thanks to the wide and medium depth eFEDS X-ray survey, the sample contains the rare and most X-ray luminous radio galaxies above the knee of the X-ray luminosity function, spanning 4422$. Those obscured and radio AGN reside in $0.4, Comment: 20 pages, 11 figures, accepted for publication in A&A
- Published
- 2023
20. Second data release of the Hyper Suprime-Cam Subaru Strategic Program
- Author
-
Hiroaki Aihara, Yusra AlSayyad, Makoto Ando, Robert Armstrong, James Bosch, Eiichi Egami, Hisanori Furusawa, Junko Furusawa, Andy Goulding, Yuichi Harikane, Chiaki Hikage, Paul T P Ho, Bau-Ching Hsieh, Song Huang, Hiroyuki Ikeda, Masatoshi Imanishi, Kei Ito, Ikuru Iwata, Anton T Jaelani, Ryota Kakuma, Kojiro Kawana, Satoshi Kikuta, Umi Kobayashi, Michitaro Koike, Yutaka Komiyama, Xiangchong Li, Yongming Liang, Yen-Ting Lin, Wentao Luo, Robert Lupton, Nate B Lust, Lauren A MacArthur, Yoshiki Matsuoka, Sogo Mineo, Hironao Miyatake, Satoshi Miyazaki, Surhud More, Ryoma Murata, Shigeru V Namiki, Atsushi J Nishizawa, Masamune Oguri, Nobuhiro Okabe, Sakurako Okamoto, Yuki Okura, Yoshiaki Ono, Masato Onodera, Masafusa Onoue, Ken Osato, Masami Ouchi, Takatoshi Shibuya, Michael A Strauss, Naoshi Sugiyama, Yasushi Suto, Masahiro Takada, Yuhei Takagi, Tadafumi Takata, Satoshi Takita, Masayuki Tanaka, Tsuyoshi Terai, Yoshiki Toba, Hisakazu Uchiyama, Yousuke Utsumi, Shiang-Yu Wang, Wenting Wang, and Yoshihiko Yamada
- Published
- 2019
- Full Text
- View/download PDF
21. A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). IX. The Most Overdense Region at z~5 Inhabited by a Massive Radio Galaxy
- Author
-
Hisakazu Uchiyama, Takuji Yamashita, Tohru Nagao, Yoshiaki Ono, Jun Toshikawa, Kohei Ichikawa, Nozomu Kawakatu, Masaru Kajisawa, Yoshiki Toba, Yoshiki Matsuoka, Mariko Kubo, Masatoshi Imanishi, Kei Ito, Toshihiro Kawaguchi, Chien-Hsiu Lee, and Tomoki Saito
- Subjects
Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies - 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 outskirt of an overdense region identified by the r-dropout galaxies at a 4.7 sigma 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 > 10^14 Msun at z=0 with a high probability of >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., 7 pages, 3 figures, accepted in PASJ
- Published
- 2022
22. NINJA : an LTAO assisted optical and near-infrared spectrograph of Subaru Telescope
- Author
-
Chihiro Tokoku, Shinobu Ozaki, Takashi Moriya, Kenshi Yanagisawa, Kentaro Motohara, Masami Ouchi, Nozomu Tominaga, Masaomi Tanaka, Yoshito Ono, Yosuke Minowa, Yutaka Hayano, Yusei Koyama, Sadman Ali, Masayuki Tanaka, Masayuki Akiyama, Tohru Nagao, Yoshiki Matsuoka, Kosuke Kushibiki, Shogo Homan, Akino Yasuda, and Michitoshi Yoshida
- Published
- 2022
23. Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). III. Star formation properties of the host galaxies at z ≳ 6 studied with ALMA
- Author
-
Takuma Izumi, Masafusa Onoue, Hikari Shirakata, Tohru Nagao, Kotaro Kohno, Yoshiki Matsuoka, Masatoshi Imanishi, Michael A Strauss, Nobunari Kashikawa, Andreas Schulze, John D Silverman, Seiji Fujimoto, Yuichi Harikane, Yoshiki Toba, Hideki Umehata, Kouichiro Nakanishi, Jenny E Greene, Yoichi Tamura, Akio Taniguchi, Yuki Yamaguchi, Tomotsugu Goto, Yasuhiro Hashimoto, Soh Ikarashi, Daisuke Iono, Kazushi Iwasawa, Chien-Hsiu Lee, Ryu Makiya, Takeo Minezaki, and Ji-Jia Tang
- Published
- 2018
- Full Text
- View/download PDF
24. Evolution of the mass relation between supermassive black holes and dark matter halos across the cosmic time
- Author
-
Aryan Bansal, Kiyotomo Ichiki, Hiroyuki Tashiro, and Yoshiki Matsuoka
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
A positive observational proof suggests that most galaxies contain a central supermassive black hole (SMBH) with mass in the range of $10^6M_\odot$ $-$ $10^{10}M_\odot$. It is suggested that the mass of SMBHs is proportionally related to that of the dark matter (DM) halo, even at $z= 6$. This implies that these SMBHs could coevolve with the host DM halos. Here, we investigate the mass evolution of SMBHs in a hierarchical structure formation by building halo merger trees using the extended Press-Schechter formalism. An SMBH with a mass that follows various power-law relations with the DM halo mass is assigned as an initial condition. Assuming that the mass growth of all black holes is due to mergers, we obtain the relation between SMBH and DM halo masses at the present epoch. By requiring that the mass of the SMBHs at $z=0$ should not be greater than the currently observed SMBH-DM halo mass relation, a lower bound on the mass of the DM halo that can contain a SMBH can be imposed at $z= 6$ as $M_{\rm lim} > 3.6 \times 10^{10} M_\odot\times (1.4-n)^{2.3}$, where $n$ is the power-law index of the SMBH-DM halo mass relation at $z=6$. Because we only consider mergers for the mass evolution of SMBHs, this model is simplistic and should underestimate the mass of SMBHs relative to the mass of the DM halo at the present epoch. Our work aims to constrain the SMBH-DM mass relation at z=6 and not build a new model to explain the observations, 10 pages, 7 figures
- Published
- 2022
25. The Obscured Fraction of Quasars at Cosmic Noon
- Author
-
Bovornpratch Vijarnwannaluk, Masayuki Akiyama, Malte Schramm, Yoshihiro Ueda, Yoshiki Matsuoka, Yoshiki Toba, Marcin Sawicki, Stephen Gwyn, and Janek Pflugradt
- Subjects
Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies - 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 datasets. A unique sample of luminous X-ray selected AGNs above $z>2$ was constructed by matching the XMM-SERVS X-ray point-source catalog with a PSF-convolved photometric catalog covering from $u^*$ to 4.5$μ\mathrm{m}$ 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 $\log N_{\rm H}\ (\rm cm^{-2})>22$, assuming parametric X-ray luminosity and absorption functions. The results suggest that $76_{-3}^{+4}\%$ of luminous quasars ($\log L_X\ (\rm erg\ s^{-1}) >44.5$) 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 $z>2$ 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., 25 Pages, 19 Figure, ApJ accepted. Updated version contains corrections based on comments from the community
- Published
- 2022
- Full Text
- View/download PDF
26. Anomalous diffusion in a randomly modulated velocity field
- Author
-
Noriaki Aibara, Naoaki Fujimoto, Yoshiki Matsuoka, So Katagiri, Akio Sugamoto, Yutaka Matsuo, Ken Yokoyama, and Tsukasa Yumibayashi
- Subjects
High Energy Physics - Theory ,History ,Polymers and Plastics ,High Energy Physics - Theory (hep-th) ,Fluid Dynamics (physics.flu-dyn) ,FOS: Physical sciences ,Physics - Fluid Dynamics ,Mathematical Physics (math-ph) ,Business and International Management ,Computational Physics (physics.comp-ph) ,Physics - Computational Physics ,Industrial and Manufacturing Engineering ,Mathematical Physics - Abstract
This paper proposes a simple model of anomalous diffusion, in which a particle moves with the velocity field induced by a single "dipole" (a doublet or a pair of source and sink), whose moment is modulated randomly at each time step. A motivation to introduce such a model is that it may serve as a toy model to investigate an anomalous diffusion of fluid particles in turbulence. We perform a numerical simulation of the fractal dimension of the trajectory using periodic boundary conditions in two and three dimensions. For a wide range of the dipole moment, we estimate the fractal dimension of the trajectory to be 1.5--1.9 (2D) and 1.6--2.7 (3D)., Comment: 21 pages, 9 figures
- Published
- 2022
- Full Text
- View/download PDF
27. On the Connection between Supermassive Black Hole and Galaxy Growth in the Reionization Epoch
- Author
-
Junyao Li, John D. Silverman, Takuma Izumi, Wanqiu He, Masayuki Akiyama, Kohei Inayoshi, Yoshiki Matsuoka, Masafusa Onoue, and Yoshiki Toba
- Subjects
Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - Abstract
The correlation between the mass of supermassive black holes (SMBHs; $\mathcal{M}_{\rm BH}$) and their host galaxies ($\mathcal{M}_\star$) in the reionization epoch provides valuable constraints on their early growth. High-redshift quasars typically have a $\mathcal{M}_{\rm BH}$/$\mathcal{M}_\star$ 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 $z\sim6$ with host properties based on ALMA observations. We find that the observed distribution of quasars in the $\mathcal{M}_{\rm BH} - \mathcal{M}_\star$ plane can be reproduced by assuming that the underlying SMBH population at $z\sim6$ follows the relationship in the local universe. However, a positive or even a negative evolution in $\mathcal{M}_{\rm BH}$/$\mathcal{M}_\star$ can also explain the data, depending on whether the intrinsic scatter evolves and 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 $\mathcal{M}_{\rm BH}$ limits are needed. Furthermore, assuming a radiative efficiency of 0.1 and quasar duty cycles estimated from the active SMBH fraction, significant outliers in $\mathcal{M}_{\rm BH}$/$\mathcal{M}_\star$ 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 $z\sim6$, with AGN feedback being a possible driver., Comment: 10 pages, 5 figures, published in ApJL
- Published
- 2022
- Full Text
- View/download PDF
28. Detection of extended millimeter emission in the host galaxy of 3C273 and its implications for QSO feedback via high dynamic range ALMA imaging
- Author
-
Shinya Komugi, Yoshiki Toba, Yoshiki Matsuoka, Toshiki Saito, and Takuji Yamashita
- Subjects
Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Astrophysics::Galaxy Astrophysics - 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.
- Published
- 2022
- Full Text
- View/download PDF
29. A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). IV. Rapidly Growing (Super)Massive Black Holes in Extremely Radio-loud Galaxies
- Author
-
Alexander Wagner, Xiaoyang Chen, Bovornpratch Vijarnwannaluk, Hikaru Fukuchi, Taiki Kawamuro, Maria Charisi, Malte Schramm, Yoshiki Matsuoka, Masayuki Akiyama, Takuji Yamashita, Masaru Kajisawa, Kohei Inayoshi, Tohru Nagao, Masayuki Tanaka, Chien-Hsiu Lee, Wanqiu He, Hyewon Suh, Janek Pflugradt, Kohei Ichikawa, Yoshiki Toba, Hisakazu Uchiyama, and Yoshihiro Ueda
- Subjects
Active galactic nucleus ,Radio galaxy ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Type (model theory) ,01 natural sciences ,symbols.namesake ,0103 physical sciences ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,Supermassive black hole ,010308 nuclear & particles physics ,Order (ring theory) ,Astronomy and Astrophysics ,Quasar ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Eddington luminosity ,symbols ,Astrophysics - High Energy Astrophysical Phenomena - Abstract
We present the optical and infrared properties of 39 extremely radio-loud galaxies discovered by cross-matching the Subaru/Hyper Suprime-Cam (HSC) deep optical imaging survey and VLA/FIRST 1.4 GHz radio survey. The recent Subaru/HSC strategic survey revealed optically-faint radio galaxies (RG) down to $g_\mathrm{AB} \sim 26$, opening a new parameter space of extremely radio-loud galaxies (ERGs) with radio-loudness parameter of $\log \mathcal{R}_\mathrm{rest} = \log (f_{1.4 \mathrm{GHz,rest}}/f_{g,\mathrm{rest}}) >4$. Because of their optical faintness and small number density of $\sim1~$deg$^{-2}$, such ERGs were difficult to find in the previous wide but shallow, or deep but small area optical surveys. ERGs show intriguing properties that are different from the conventional RGs: (1) most ERGs reside above or on the star-forming main-sequence, and some of them might be low-mass galaxies with $\log (M_\star/M_\odot) < 10$. (2) ERGs exhibit a high specific black hole accretion rate, reaching the order of the Eddington limit. The intrinsic radio-loudness ($\mathcal{R}_\mathrm{int}$), defined by the ratio of jet power over bolometric radiation luminosity, is one order of magnitude higher than that of radio quasars. This suggests that ERGs harbor a unique type of active galactic nuclei (AGN) that show both powerful radiations and jets. Therefore, ERGs are prominent candidates of very rapidly growing black holes reaching Eddington-limited accretion just before the onset of intensive AGN feedback., 20 pages, 10 figures, accepted for publication in ApJ
- Published
- 2021
30. Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XIV. A Candidate Type-II Quasar at z=6.1292
- Author
-
Nobunari Kashikawa, Michael A. Strauss, Takuma Izumi, Takatoshi Shibuya, Takuya Hashimoto, Yoshiki Toba, Tohru Nagao, Kazushi Iwasawa, Masatoshi Imanishi, Yoshiki Matsuoka, Yuichi Harikane, Masafusa Onoue, Seiji Fujimoto, Chien-Hsiu Lee, Naoko Asami, Japan Society for the Promotion of Science, Ministry of Education, Culture, Sports, Science and Technology (Japan), Japan Science and Technology Agency, and Kavli Institute for Particle Astrophysics and Cosmology
- Subjects
Physics ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Quasar ,Astrophysics ,Quasars ,Astrophysics - Astrophysics of Galaxies ,Luminosity - Abstract
Onoue, Masafusa, et al., We present deep Keck/MOSFIRE near-infrared spectroscopy of a strong Lyα emitting source at z = 6.1292, HSC J142331.71-001809.1, which was discovered by the SHELLQS program from imaging data of the Subaru Hyper Suprime-Cam (HSC) survey. This source is one of five objects that show narrow (FWHM < 500 km s-1) and prominent (LLyα > 1044 erg s-1) Lyα emission lines at absolute 1450 Å continuum magnitudes of M1450∼-22 mag. Its rest-frame Lyα equivalent width (EW) is 370 ± 30 Å. In the 2 hr Keck/MOSFIRE spectrum in Y band, the high-ionization C IV λλ1548,1550 doublet emission line was clearly detected with = - FWHM 120+20 20 km s-1 and a total rest-frame EW of - 37+5 6 Å. We also report the detection of weak continuum emission, and the tentative detection of O III]λλ1661,1666 in the 4 hr J-band spectrum. Judging from the UV magnitude, line widths, luminosities, and EWs of Lyα and C IV, we suggest that this source is a reionization-era analog of classical type-II AGNs, although there is a possibility that it represents a new population of AGN/galaxy composite objects in the early universe. We compare the properties of J1423-0018 to intermediate-redshift type-II AGNs and C IV emitters seen in z = 6-7 galaxy samples. Further observations of other metal emission lines in the rest-frame UV or optical, along with X-ray follow-up observations of the z = 6-7 narrow-line quasars, are needed for more robust diagnostics and to determine their nature., Funding was contributed by the FIRST program from Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. This work was supported by JSPS KAKENHI grant Nos. 17H04830 (YM), 20H01949 (TN), 18J01050 (YT). M.O. was supported by the ERC Advanced Grant 740246 Cosmic gas. Y. M. was supported by the Mitsubishi Foundation grant No. 30140. T.H. was supported by Leading Initiative for Excellent Young Researchers, MEXT, Japan (HJH02007).
- Published
- 2021
31. Why Do Carbonate Anions Have Extremely High Stability in the Interlayer Space of Layered Double Hydroxides? Case Study of Layered Double Hydroxide Consisting of Mg and Al (Mg/Al = 2)
- Author
-
Shogo Kawaguchi, Takuya Fujimura, Ryo Sasai, Shinobu Ohki, Chikako Moriyoshi, Mako Numoto, Tomohiro Abe, Naoto Oita, Shinsuke Ishihara, Koki Hagura, Yasuhiro Fujii, Masataka Tansho, Kenzo Deguchi, Tadashi Shimizu, Yoshiki Matsuoka, Hiroaki Sato, and Mako Sugata
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Inorganic chemistry ,Layered double hydroxides ,engineering ,Carbonate ,Hydroxide ,Physical and Theoretical Chemistry ,engineering.material - Abstract
Layered double hydroxides (LDHs) are promising compounds in a wide range of fields. However, exchange of CO32– anions with other anions is necessary, because the CO32– anions are strongly affixed i...
- Published
- 2019
32. Rapid evolution and transformation into quiescence?: ALMA view on z > 6 low-luminosity quasars
- Author
-
Takeo Minezaki, Nobunari Kashikawa, Akio Taniguchi, Michael A. Strauss, John D. Silverman, Jenny E. Greene, Kazushi Iwasawa, Masafusa Onoue, Hikari Shirakata, Kotaro Kohno, Kouichiro Nakanishi, Yoshiki Toba, Yoshihiro Ueda, Yuichi Harikane, Ji Jia Tang, Yasuhiro Hashimoto, Chien-Hsiu Lee, Hideki Umehata, S. Ikarashi, Yoichi Tamura, Takuma Izumi, Tomotsugu Goto, Daisuke Iono, Masatoshi Imanishi, Yoshiki Matsuoka, Seiji Fujimoto, and Tohru Nagao
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Mass distribution ,Continuum (design consultancy) ,Astronomy and Astrophysics ,Quasar ,Astrophysics ,01 natural sciences ,Galaxy ,Luminosity ,Space and Planetary Science ,0103 physical sciences ,010303 astronomy & astrophysics ,Order of magnitude ,0105 earth and related environmental sciences ,Line (formation) - Abstract
We present ALMA [CII] line and far-infrared (FIR) continuum observations of seven z > 6 low-luminosity quasars (M1450 > −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 LFIR < 1011L⊙ to ∼2 × 1012L⊙. 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.
- Published
- 2019
33. Examination of Characteristics of Qualitative Evaluation System of Hand Hygiene
- Author
-
Fumihiro Kobayashi, Yoshiki Matsuoka, Tsuneko Todoroki, Shohei Katsuno, Homare Banba, Makiko Shibano, and Yoko Kazama
- Subjects
Medical education ,Evaluation system ,Hygiene ,media_common.quotation_subject ,Psychology ,media_common - Published
- 2018
34. Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XII. Extended [C ii] Structure (Merger or Outflow) in a z = 6.72 Red Quasar
- Author
-
Toshihiro Kawaguchi, John D. Silverman, Takeo Minezaki, Takuma Izumi, Nobunari Kashikawa, Kotaro Kohno, Kianhong Lee, Masafusa Onoue, Ji Jia Tang, Kohei Inayoshi, Kouichiro Nakanishi, Michael A. Strauss, Yoichi Tamura, Yoshiki Toba, Masatoshi Imanishi, Kazushi Iwasawa, Yoshihiro Ueda, Hyewon Suh, Akio K. Inoue, Yuichi Harikane, M. Schramm, Chien-Hsiu Lee, Daisuke Iono, Hideki Umehata, Taiki Kawamuro, Seiji Fujimoto, Takuya Hashimoto, Tohru Nagao, Yasuhiro Hashimoto, Yoshiki Matsuoka, Shunsuke Baba, S. Ikarashi, Suzuka Nakano, Tomotsugu Goto, Japan Science and Technology Agency, Ministry of Education, Culture, Sports, Science and Technology (Japan), and Toray Science Foundation
- Subjects
Physics ,Active galactic nuclei ,Galaxy formation ,Active galactic nucleus ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Quasar ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Submillimetre astronomy ,Luminosity ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Galaxy evolution ,Galaxy formation and evolution ,High-redshift galaxies ,Astrophysics::Solar and Stellar Astrophysics ,Outflow ,Quasars ,AGN host galaxies ,Submillimeter astronomy ,Astrophysics::Galaxy Astrophysics - Abstract
Izumi, T., et al., 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 × 1012 L o˙. 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 o˙ 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 o˙ 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., Funding was contributed by the FIRST program of the Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science, and Technology, the Japan Society for the Promotion of Science, the Japan Science and Technology Agency, the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. T.I. is supported by an ALMA Japan Research Grant of the NAOJ ALMA Project, NAOJ-ALMA-249.
- Published
- 2021
35. Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XIII. Large-scale Feedback and Star Formation in a Low-Luminosity Quasar at z = 7.07 on the Local Black Hole to Host Mass Relation
- Author
-
Taiki Kawamuro, Chien-Hsiu Lee, Soh Ikarashi, John D. Silverman, Hideki Umehata, Kohei Inayoshi, Hyewon Suh, Malte Schramm, Masafusa Onoue, Michael A. Strauss, Nobunari Kashikawa, Kotaro Kohno, Shunsuke Baba, Kouichiro Nakanishi, Yoshiki Toba, Toshihiro Kawaguchi, Takuya Hashimoto, Tohru Nagao, Seiji Fujimoto, Yoshihiro Ueda, Takuma Izumi, Akio K. Inoue, Masatoshi Imanishi, Kazushi Iwasawa, Yoshiki Matsuoka, Ministry of Education, Culture, Sports, Science and Technology (Japan), Japan Society for the Promotion of Science, Japan Science and Technology Agency, Toray Science Foundation, Princeton University, and Kavli Institute for Particle Astrophysics and Cosmology
- Subjects
010504 meteorology & atmospheric sciences ,FOS: Physical sciences ,Astrophysics ,01 natural sciences ,Luminosity ,Bulge ,Interstellar medium ,Galaxy evolution ,0103 physical sciences ,Continuum (set theory) ,010303 astronomy & astrophysics ,Quasars ,Galaxy rotation curve ,AGN host galaxies ,0105 earth and related environmental sciences ,Physics ,Star formation ,Astronomy and Astrophysics ,Quasar ,Mass ratio ,Astrophysics - Astrophysics of Galaxies ,Black hole ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Active galaxies ,High-redshift galaxies ,Submillimeter astronomy - Abstract
Izumi, T., et al., We present Atacama Large Millimeter/submillimeter Array [C ii] 158 μm line and underlying far-infrared (FIR) continuum emission observations (0.″70 × 0.″56 resolution) toward HSC J124353.93+010038.5 (J1243+0100) at z = 7.07, the only low-luminosity (M 1450 > -25 mag) quasar currently known at z > 7. The FIR continuum is bright (1.52 mJy) and resolved with a total luminosity of L FIR = 3.5 × 1012 L o˙. The spatially extended component is responsible for ∼40% of the emission. The area-integrated [C ii] spectrum shows a broad wing (FWHM = 997 km s-1, L [C ii] = 1.2 × 109 L o˙), as well as a bright core (FWHM = 235 km s-1, L [C ii] = 1.9 × 109 L o˙). This wing is the first detection of a galactic-scale quasar-driven outflow (atomic outflow rate >447 M o˙ yr-1) at z > 7. The estimated large mass-loading factor of the total outflow (e.g., ⪆9 relative to the [C ii]-based star formation rate) suggests that this outflow will soon quench the star formation of the host. The core gas dynamics are governed by rotation, with a rotation curve suggestive of a compact bulge (∼3.3 × 1010 M o˙), although it is not yet spatially resolved. Finally, we found that J1243+0100 has a black hole mass-to-dynamical mass (and -to-bulge mass) ratio of ∼0.4% (∼1%), consistent with the local value within the uncertainties. Our results therefore suggest that the black hole-host coevolution relation is already in place at z ∼ 7 for this object., Funding was contributed by the FIRST program from the Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), the Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. T.H. was supported by th
- Published
- 2021
- Full Text
- View/download PDF
36. Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XVI. 69 New Quasars at 5.8 < z < 7.0
- Author
-
Yoshiki Matsuoka, Kazushi Iwasawa, Masafusa Onoue, Takuma Izumi, Nobunari Kashikawa, Michael A. Strauss, Masatoshi Imanishi, Tohru Nagao, Masayuki Akiyama, John D. Silverman, Naoko Asami, James Bosch, Hisanori Furusawa, Tomotsugu Goto, James E. Gunn, Yuichi Harikane, Hiroyuki Ikeda, Rikako Ishimoto, Toshihiro Kawaguchi, Nanako Kato, Satoshi Kikuta, Kotaro Kohno, Yutaka Komiyama, Chien-Hsiu Lee, Robert H. Lupton, Takeo Minezaki, Satoshi Miyazaki, Hitoshi Murayama, Atsushi J. Nishizawa, Masamune Oguri, Yoshiaki Ono, Masami Ouchi, Paul A. Price, Hiroaki Sameshima, Naoshi Sugiyama, Philip J. Tait, Masahiro Takada, Ayumi Takahashi, Tadafumi Takata, Masayuki Tanaka, Yoshiki Toba, Yousuke Utsumi, Shiang-Yu Wang, Takuji Yamashita, Japan Society for the Promotion of Science, Mitsubishi International Corporation, and Ministerio de Ciencia e Innovación (España)
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Reionization ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Supermassive black holes ,High-redshift galaxies ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Quasars ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present the spectroscopic discovery of 69 quasars at 5.8 < z < 7.0, drawn from the Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP) imaging survey data. This is the 16th publication from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, and completes identification of all but the faintest candidates (i.e., i-band dropouts with zAB < 24 and y-band detections, and z-band dropouts with yAB < 24) with Bayesian quasar probability Pq > 0.1 in the HSC-SSP third public data release (PDR3). The sample reported here also includes three quasars with Pq < 0.1 at z ~ 6.6, which we selected in an effort to completely cover the reddest point sources with simple color cuts. The number of high-z quasars discovered in SHELLQs has now grown to 162, including 23 type-II quasar candidates. This paper also presents identification of seven galaxies at 5.6 < z < 6.7, an [O III] emitter at z = 0.954, and 31 Galactic cool stars and brown dwarfs. High-z quasars and galaxies comprise 75 % and 16 % respectively of all the spectroscopic SHELLQs objects that pass our latest selection algorithm with the PDR3 photometry. That is, a total of 91 % of the objects lie at z > 5.6. This demonstrates that the algorithm has very high efficiency, even though we are probing an unprecedentedly low-luminosity population down to M1450 ~ -21 mag., Accepted for publication in The Astrophysical Journal Supplement Series
- Published
- 2021
- Full Text
- View/download PDF
37. Faint Quasars Live in the Same Number Density Environments as Lyman Break Galaxies at z∼4
- Author
-
Yongming Liang, Nobunari Kashikawa, Murilo Marinello, Masafusa Onoue, Mariko Kubo, Kei Ito, Yuichi Harikane, Shogo Ishikawa, Masayuki Tanaka, Tohru Nagao, Jun Toshikawa, Masatoshi Imanishi, Shigeru V. Namiki, Yoshiki Matsuoka, Yutaka Komiyama, Hisakazu Uchiyama, Kohei Ichikawa, Masayuki Akiyama, and Roderik Overzier
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Angular distance ,media_common.quotation_subject ,FOS: Physical sciences ,Sigma ,Astronomy and Astrophysics ,Quasar ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Galaxy ,Luminosity ,Space and Planetary Science ,Sky ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Galaxy formation and evolution ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Cosmic dust ,media_common - Abstract
Characterizing high-z quasar environments is key to understanding the co-evolution of quasars and the surrounding galaxies. To restrict their global picture, we statistically examine the g-dropout galaxy overdensity distribution around 570 faint quasar candidates at z ~ 4, based on the Hyper Suprime-Cam Subaru Strategic Program survey. We compare the overdensity significances of g-dropout galaxies around the quasars with those around g-dropout galaxies, and find no significant difference between their distributions. A total of 4 (22) out of the 570 faint quasars, 0.7_{-0.4}^{+0.4} (3.9_{-0.8}^{+0.8}) %, are found to be associated with the > 4 sigma overdense regions within an angular separation of 1.8 (3.0) arcmin, which is the typical size of protoclusters at this epoch. This is similar to the fraction of g-dropout galaxies associated with the > 4 sigma overdense regions. This result is consistent with our previous work that 1.3_{-0.9}^{+0.9} % and 2.0_{-1.1}^{+1.1} % of luminous quasars detected in the Sloan Digital Sky Survey exist in the > 4 sigma overdense regions within 1.8 and 3.0 arcmin separations, respectively. Therefore, we suggest that the galaxy number densities around quasars are independent of their luminosity, and most quasars do not preferentially appear in the richest protocluster regions at z ~ 4. The lack of an apparent positive correlation between the quasars and the protoclusters implies that: i) the gas-rich major merger rate is relatively low in the protocluster regions, ii) most high-z quasars may appear through secular processes, or iii) some dust-obscured quasars exist in the protocluster regions., 12 pages, 4 figures
- Published
- 2020
38. Follow-up Observations for IceCube-170922A: Detection of Rapid Near-Infrared Variability and Intensive Monitoring of TXS 0506+056
- Author
-
Masayuki Yamanaka, Masaki Takayama, Wei Liu, Mahito Sasada, Hiroki Kimura, Ryuhei Ohnishi, Nozomu Tominaga, C. K. Gilligan, Yuina Yamazaki, Tomoki Morokuma, Ryou Ohsawa, Koji S. Kawabata, Shigeyuki Sako, Kumiko Morihana, Takuji Yamashita, Shigehiro Nagataki, Katsuhiro L. Murata, Michitoshi Yoshida, Hiroki Mori, Maiko Chogi, Masaomi Tanaka, Yoshiyuki Inoue, Mariko Kimura, Yasuyuki Wakamatsu, Yousuke Utsumi, Kengo Takagi, Miho Kawabata, Ruochen Huang, Naoki Kawahara, Yasuyuki T. Tanaka, Yoshiki Matsuoka, Hiroki Nagashima, Ryosuke Itoh, Kouji Ohta, Tatsuya Nakaoka, Taisei Abe, Satoshi Honda, and Keisuke Isogai
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,010308 nuclear & particles physics ,Near-infrared spectroscopy ,Polarimetry ,FOS: Physical sciences ,Flux ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Wavelength ,Amplitude ,Neutrino detector ,Space and Planetary Science ,0103 physical sciences ,14. Life underwater ,Neutrino ,Blazar ,Astrophysics - High Energy Astrophysical Phenomena ,010303 astronomy & astrophysics - Abstract
We present our follow-up observations to search for an electromagnetic counterpart of the IceCube high-energy neutrino, IceCube-170922A. Monitoring observations of a likely counterpart, TXS 0506+056, are also described. First, we quickly took optical and near-infrared images of 7 flat-spectrum radio sources within the IceCube error region right after the neutrino detection and found a rapid flux decline of TXS 0506+056 in Kanata/HONIR J-band data. Motivated by this discovery, intensive follow-up observations of TXS 0506+056 are continuously done, including our monitoring imaging observations, spectroscopic observations, and polarimetric observations in optical and near-infrared wavelengths. TXS 0506+056 shows a large amplitude (~1.0 mag) variability in a time scale of several days or longer, although no significant variability is detected in a time scale of a day or shorter. TXS 0506+056 also shows a bluer-when-brighter trend in optical and near-infrared wavelengths. Structure functions of variabilities are examined and indicate that TXS 0506+056 is not a special blazar in terms of optical variability. Polarization measurement results of TXS 0506+056 are also discussed., 19 pages, 10 figures, 4 tables. Accepted for publication in Publications of the Astronomical Society of Japan (PASJ)
- Published
- 2020
39. Multiline Assessment of Narrow-line Regions in z ∼ 3 Radio Galaxies
- Author
-
Koki Terao, Tohru Nagao, Kyoko Onishi, Kenta Matsuoka, Masayuki Akiyama, Yoshiki Matsuoka, and Takuji Yamashita
- Subjects
Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - Abstract
In this paper, we utilize high-quality rest-UV spectra of three radio galaxies at $z \sim$ 3 observed with VLT/FORS2 to measure the flux of several emission lines including relatively faint ones, such as NIV]$\lambda$1486, OIII]$\lambda$1663, and [NeIV]$\lambda$2424. Additionally, we collect fluxes of faint rest-UV emission lines in 12 $z \sim$ 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., NV$\lambda$1240, CIV$\lambda$1549, HeII$\lambda$1640, and CIII]$\lambda$1909). 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 $z \sim$ 3 is solar or super-solar, without assuming the gas density and ionization parameter thanks to the constrains from the faint emission lines. This result suggests that high-$z$ radio galaxies are already chemically matured at $z \sim$ 3., Comment: 17 pages, 10 figures, accepted for publication in the ApJ
- Published
- 2022
40. GOLDRUSH. IV. Luminosity Functions and Clustering Revealed with ∼4,000,000 Galaxies at z ∼ 2–7: Galaxy–AGN Transition, Star Formation Efficiency, and Implication for Evolution at z > 10
- Author
-
Yuichi Harikane, Yoshiaki Ono, Masami Ouchi, Chengze Liu, Marcin Sawicki, Takatoshi Shibuya, Peter S. Behroozi, Wanqiu He, Kazuhiro Shimasaku, Stephane Arnouts, Jean Coupon, Seiji Fujimoto, Stephen Gwyn, Jiasheng Huang, Akio K. Inoue, Nobunari Kashikawa, Yutaka Komiyama, Yoshiki Matsuoka, Chris J. Willott, Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Galaxy formation ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,[SDU]Sciences of the Universe [physics] ,Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,Galaxy evolution ,High-redshift galaxies ,Astrophysics::Solar and Stellar Astrophysics ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,Astrophysics::Galaxy Astrophysics - 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 ~0.002-2000L*uv combined with previous studies, revealing that the dropout luminosity function is a superposition of the AGN luminosity function dominant at Muv-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 >2sigma levels, which is possibly made by inefficient mass quenching, low dust obscuration, and/or hidden AGN activity. By analyzing the correlation functions at z~2-6 with halo occupation distribution 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, SFR/(dMh/dt), 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 z10 with $\propto10^{-0.5(1+z)}$, which will be directly tested with JWST., Comment: 53 pages, 26 figures, 10 tables, accepted for publication in ApJS. Dropout galaxy catalogs are available on our project webpage (http://cos.icrr.u-tokyo.ac.jp/rush.html)
- Published
- 2022
41. Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). IX. Identification of two red quasars at z > 5.6
- Author
-
Nobunari Kashikawa, Michael A. Strauss, Seiji Fujimoto, Takeo Minezaki, Kazushi Iwasawa, Toshihiro Kawaguchi, Nanako Kato, Yoshiki Toba, Masatoshi Imanishi, Akatoki Noboriguchi, Masayuki Akiyama, Takuma Izumi, Masafusa Onoue, Tohru Nagao, Yoshiki Matsuoka, Shuhei Koyama, Chien-Hsiu Lee, Japan Society for the Promotion of Science, and National Aeronautics and Space Administration (US)
- Subjects
Physics::Instrumentation and Detectors ,Infrared ,DATA RELEASE ,Astrophysics::High Energy Astrophysical Phenomena ,media_common.quotation_subject ,REDSHIFT ,Extinction (astronomy) ,Z-GREATER-THAN-5.7 QUASARS ,FOS: Physical sciences ,DUST ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Computer Science::Digital Libraries ,01 natural sciences ,ABSORPTION-LINE QUASARS ,Luminosity ,Optical imaging ,ELLIPTIC GALAXIES ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,BLACK-HOLES ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,media_common ,Physics ,general [quasars] ,010308 nuclear & particles physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Quasar ,Limiting ,Astrophysics - Astrophysics of Galaxies ,early universe ,Universe ,TO 6 QUASARS ,13. Climate action ,Space and Planetary Science ,DISCOVERY ,Astrophysics of Galaxies (astro-ph.GA) ,DIGITAL SKY SURVEY ,Spectral energy distribution ,high-redshift [galaxies] - Abstract
arXiv:2007.08685v2, We present the first discovery of dust-reddened quasars (red quasars) in the high-z universe (z > 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) > 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., We are grateful to the referee for his/her useful comments to improve this paper. YM was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI grant No. JP17H04830 and the Mitsubishi Foundation grant No. 30140. TI acknowledges supports from the JSPS grant No. JP17K14247. The Hyper Suprime-Cam (HSC) collaboration includes the astronomical communities of Japan and Taiwan, and Princeton University. The HSC instrumentation and software were developed by the National Astronomical Observatory of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA), and Princeton University. Funding was contributed by the FIRST program from Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University. The Pan-STARRS1 Surveys (PS1) have been made possible through contributions of the Institute for Astronomy, the University of Hawaii, the Pan-STARRS Project Office, the Max-Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, Queen’s University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under Grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, the National Science Foundation under Grant No. AST-1238877, the University of Maryland, and Eotvos Lorand University (ELTE). This paper makes use of software developed for the Large Synoptic Survey Telescope. We thank the LSST Project for making their code available as free software at 〈http://dm.lsst.org. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration.
- Published
- 2020
42. Subaru Hyper Suprime-Cam view of quasar host galaxies at z < 1
- Author
-
Malte Schramm, Yoshiaki Taniguchi, Takeo Minezaki, Yuya Saeda, Yoshiki Toba, Andy D. Goulding, John D. Silverman, Toru Ishino, Shuhei Koyama, Toshihiro Kawaguchi, Akatoki Noboriguchi, Michael A. Strauss, Yoshiki Matsuoka, Masatoshi Imanishi, and Tohru Nagao
- Subjects
Physics ,Sample selection ,Supermassive black hole ,Active galactic nucleus ,Stellar mass ,010308 nuclear & particles physics ,Star formation ,Astrophysics::High Energy Astrophysical Phenomena ,Flux ,Astronomy and Astrophysics ,Quasar ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Galaxy ,Space and Planetary Science ,0103 physical sciences ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics - Abstract
Active galactic nuclei (AGNs) are key for 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 co-evolution. From a parent sample of 1151 z < 1 type-1 quasars from the Sloan Digital Sky Survey quasar catalog, we detected host galaxies of 862 of them in the high-quality grizy images of the Subaru Hyper Suprime-Cam (HSC) survey. The unprecedented combination of the survey area and depth allows us to perform a statistical analysis of the quasar host galaxies, with small sample variance. We fit the radial image profile of each quasar as a linear combination of the point spread function and the Sersic 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 > 10^(10) Msun, and are mainly located on the green valley. This trend is consistent with a scenario in which star formation of 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 < 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., Comment: Accepted for publication in PASJ
- Published
- 2020
43. Large population of ALMA galaxies at z > 6 with very high [O III] 88 m to [C II] 158 m flux ratios: evidence of extremely high ionization parameter or PDR deficit?
- Author
-
Yuma Sugahara, Kotaro Kohno, Eiichi Egami, Ken-ichi Tadaki, Akio K. Inoue, Hiroshi Matsuo, Livia Vallini, Yuichi Matsuda, Masami Ouchi, Yoichi Tamura, Andrea Ferrara, Takatoshi Shibuya, Yuichi Harikane, T. Bakx, Takuya Hashimoto, Takashi Kojima, Yoshiaki Ono, Tohru Nagao, Kana Moriwaki, Yoshiki Matsuoka, Andrea Pallottini, Simona Gallerani, Seiji Fujimoto, Harikane, Y., Ouchi, M., Inoue, A. K., Matsuoka, Y., Tamura, Y., Bakx, T., Fujimoto, S., Moriwaki, K., Ono, Y., Nagao, T., Tadaki, K. -I., Kojima, T., Shibuya, T., Egami, E., Ferrara, A., Gallerani, S., Hashimoto, T., Kohno, K., Matsuda, Y., Matsuo, H., Pallottini, A., Sugahara, Y., and Vallini, L.
- Subjects
Physics ,010308 nuclear & particles physics ,Doubly ionized oxygen ,Flux ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Abundance of the chemical elements ,Luminosity ,Space and Planetary Science ,Ionization ,0103 physical sciences ,Galaxy formation and evolution ,010303 astronomy & astrophysics ,Cosmic dust - Abstract
We present our new ALMA observations targeting [OIII]88um, [CII]158um, [NII]122um, 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 [OIII] and [CII] lines from all of the galaxies at 4.3-11.8sigma 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 [OIII]/[CII] ratios of L[OIII]/L[CII]~3-20, ~10 times higher than z~0 galaxies. We also find a positive correlation between the [OIII]/[CII] ratio and the Lya equivalent width (EW) at the ~90% confidence level. We carefully investigate physical origins of the high [OIII]/[CII] 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 [OIII]/[CII] 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 [NII] observations. The latter scenario can be reproduced with a density bounded nebula with PDR deficit, which would enhance the Lya, Lyman continuum, and C+ ionizing photons escape from galaxies, consistent with the [OIII]/[CII]-Lya EW correlation we find., Comment: 20 pages, 18 figures, Accepted for publication in ApJ
- Published
- 2020
44. Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). III. Discovery of a z = 4.72 Radio Galaxy with Lyman Break Technique
- Author
-
Masayuki Akiyama, Takuji Yamashita, Masafusa Onoue, Hisakazu Uchiyama, Kianhong Lee, Masaru Kajisawa, Mana Niida, Yoshiki Toba, Chien-Hsiu Lee, Kotaro Kohno, Hiroyuki Ikeda, Kazuyuki Ogura, Yoshiaki Ono, Yoshiki Matsuoka, Taiki Kawamuro, Tohru Nagao, Toshihiro Kawaguchi, Yuichi Harikane, Masayuki Tanaka, and Kohei Ichikawa
- Subjects
Physics ,Active galactic nucleus ,010504 meteorology & atmospheric sciences ,Radio galaxy ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Spectral line ,Red shift ,Photometry (astronomy) ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Spectroscopy ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
We report a discovery of $z = 4.72$ radio galaxy, HSC J083913.17+011308.1, by using the Lyman break technique with the Hyper Suprime-Cam Subaru Strategic Survey (HSC-SSP) catalog for VLA FIRST radio sources. The number of known high-$z$ radio galaxies (HzRGs) at $z > 3$ is quite small to constrain the evolution of HzRGs so far. The deep and wide-area optical survey by HSC-SSP enables us to apply the Lyman break technique to a large search for HzRGs. For an HzRG candidate among pre-selected $r$-band dropouts with a radio detection, a follow-up optical spectroscopy with GMOS/Gemini has been performed. The obtained spectrum presents a clear Ly$\alpha$ emission line redshifted to $z=4.72$. The SED fitting analysis with the rest-frame UV and optical photometries suggests the massive nature of this HzRG with $\log{M_*/M_{\odot}} = 11.4$. The small equivalent width of Ly$\alpha$ and the moderately red UV colors indicate its dusty host galaxy, implying a chemically evolved and dusty system. The radio spectral index does not meet a criterion for an ultra-steep spectrum: $\alpha^{325}_{1400}$ of $-1.1$ and $\alpha^{150}_{1400}$ of $-0.9$, demonstrating that the HSC-SSP survey compensates for a sub-population of HzRGs which are missed in surveys focusing on an ultra-steep spectral index., Comment: 10 pages, 5 figures, accepted for publication in AJ
- Published
- 2020
45. The Mean Absorption Line Spectra of a Selection of Luminous z~6 Lyman Break Galaxies
- Author
-
Yoshiki Matsuoka, Yuichi Harikane, Nicolas Laporte, and Richard S. Ellis
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Stellar mass ,Star formation ,Metallicity ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Astrophysics - Astrophysics of Galaxies ,Galaxy ,Redshift ,Luminosity ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Galaxy formation and evolution ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Reionization ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences - Abstract
We examine the absorption line spectra of a sample of 31 luminous (M_UV=-23) Lyman break galaxies at redshift z~6 using data taken with the FOCAS and OSIRIS spectrographs on the Subaru and GTC telescopes. For two of these sources we present longer exposure data taken at higher spectral resolution from ESO's X-shooter spectrograph. Using these data, we demonstrate the practicality of stacking our lower resolution data to measure the depth of various interstellar and stellar absorption lines to probe the covering fraction of low ionization gas and the gas-phase and stellar metallicities near the end of the era of cosmic reionization. From maximum absorption line depths of SiII1260 and CII1334, we infer a mean covering fraction of >0.85+/-0.16 for our sample. This is larger than that determined using similar methods for lower luminosity galaxies at slightly lower redshifts, suggesting that the most luminous galaxies appear to have a lower escape fraction than fainter galaxies, and therefore may not play a prominent role in concluding reionization. Using various interstellar absorption lines we deduce gas-phase metallicities close to solar indicative of substantial early enrichment. Using selected stellar absorption lines, we model our spectra with a range of metallicities using techniques successfully employed at lower redshift and deduce a stellar metallicity of 0.4 +0.3/-0.1 solar, consistent with the stellar mass - stellar metallicity relation recently found at z~3-5. We discuss the implications of these metallicity estimates for the typical ages of our luminous galaxies and conclude our results imply initial star formation at redshifts z~10, consistent with independent analyses of earlier objects., 13 pages, 10 figures, 3 tables, Accepted for Publication in ApJ
- Published
- 2020
46. Dual supermassive black holes at close separation revealed by the Hyper Suprime-Cam Subaru Strategic Program
- Author
-
Khee Gan Lee, Kazushi Iwasawa, Yuichi Matsuda, Masatoshi Imanishi, Michael A. Strauss, Hyewon Suh, Yoshihiro Ueda, Issha Kayo, Masafusa Onoue, Kazuhiro Shimasaku, Wentao Luo, Shenli Tang, Toshihiro Kawaguchi, Seiji Fujimoto, Tilman Hartwig, Chiaki Hikage, Malte Schramm, Yoshiaki Taniguchi, Nobunari Kashikawa, Xuheng Ding, John D. Silverman, Masamune Oguri, Kotaro Kohno, Masami Ouchi, Tohru Nagao, Knud Jahnke, Yoshiki Toba, Naoki Yasuda, Yoshiaki Ono, Yoshiki Matsuoka, Andy D. Goulding, Rogemar A. Riffel, Nao Suzuki, National Science Foundation (US), National Aeronautics and Space Administration (US), Kavli Institute for Particle Astrophysics and Cosmology, Department of Energy (US), Higher Education Funding Council for England, Ministerio de Ciencia y Tecnología (España), University of Illinois, University of Chicago, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), German Research Foundation, Ministerio de Economía y Competitividad (España), European Commission, University of California, University of Cambridge, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (España), University of Edinburgh, University of Michigan, National Optical Astronomy Observatory (US), University of Nottingham, The Ohio State University, University of Pennsylvania, University of Sussex, and Texas A&M University
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - Astrophysics of Galaxies ,7. Clean energy ,01 natural sciences ,Red shift ,13. Climate action ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,010303 astronomy & astrophysics ,Humanities ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences - Abstract
Full author list: John D. Silverman, Shenli Tang, Khee-Gan Lee, Tilman Hartwig, Andy Goulding, Michael A. Strauss, Malte Schramm, Xuheng Ding, Rogemar A. Riffel, Seiji Fujimoto, Chiaki Hikage, Masatoshi Imanishi, Kazushi Iwasawa, Knud Jahnke, Issha Kayo, Nobunari Kashikawa, Toshihiro Kawaguchi, Kotaro Kohno, Wentao Luo, Yoshiki Matsuoka, Yuichi Matsuda, Tohru Nagao, Masamune Oguri, Yoshiaki Ono, Masafusa Onoue, Masami Ouchi, Kazuhiro Shimasaku, Hyewon Suh, Nao Suzuki, Yoshiaki Taniguchi, Yoshiki Toba, Yoshihiro Ueda, and Naoki Yasuda, The unique combination of superb spatial resolution, wide-area coverage, and deep depth of the optical imaging from the Hyper Suprime-Cam (HSC) Subaru Strategic Program is utilized to search for dual quasar candidates. Using an automated image analysis routine on 34,476 known Sloan Digital Sky Survey quasars, we identify those with two (or more) distinct optical point sources in HSC images covering 796 deg2. We find 421 candidates out to a redshift of 4.5 of which one hundred or so are more likely after filtering out contaminating stars. Angular separations of 0.″6-4.″0 correspond to projected separations of 3-30 kpc, a range relatively unexplored for population studies of luminous dual quasars. Using Keck I/Low Resolution Imaging Spectrometer and Gemini-N/Near-Infrared Integral Field Spectrometer, we spectroscopically confirm three dual quasar systems at z < 1, two of which are previously unknown out of eight observed, based on the presence of characteristic broad emission lines in each component, while highlighting that the continuum of one object in one of the pairs is reddened. In all cases, the [O iii]λ5007 emission lines have mild velocity offsets, thus the joint [O iii] line profile is not double-peaked. We find a dual quasar fraction of 0.26 ± 0.18% and no evidence for evolution. A comparison with the Horizon-AGN simulation seems to support the case of no evolution in the dual quasar fraction when broadly matching the quasar selection. These results may indicate a scenario in which the frequency of the simultaneous triggering of luminous quasars is not as sensitive as expected to the cosmic evolution of the merger rate or gas content of galaxies., R. Morgan thanks the LSSTC Data Science Fellowship Program, which is funded by LSSTC, NSF Cybertraining Grant #1829740, the Brinson Foundation, and the Moore Foundation; his participation in the program has benefited this work. F. O.E. acknowledges support from the FONDECYT grant No. 1201223. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under grant No. 1744555. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and AstroParticle Physics at The Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovação, the Deutsche Forschungsgemeinschaft, and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgenössische Technische Hochschule (ETH) Zürich, Fermi National Accelerator Laboratory, the University of Illinois at UrbanaChampaign, the Institut de Ciències de l’Espai (IEEC/CSIC), the Institut de Física d’Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universität München and the associated Excellence Cluster Universe, the University of Michigan, NFS’s NOIRLab, the University of Nottingham, The Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, Texas A&M University, and the OzDES Membership Consortium. The UCSC team is supported in part by NASA grant NNG17PX03C, NSF grant AST-1815935, the Gordon & Betty Moore Foundation, the Heising-Simons Foundation, and by fellowships from the David and Lucile Packard Foundation to R.J.F. Based in part on observations at Cerro Tololo InterAmerican Observatory at NSFʼs NOIRLab (NOIRLab Prop. ID 2012B-0001; PI: J. Frieman), which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, Inovação e Comunicações (MCTIC) da República Federativa do Brasil, the U.S. NSF’s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). The DES data management system is supported by the National Science Foundation under grant Nos. AST-1138766 and AST-1536171. The DES participants from Spanish institutions are partially supported by MICINN under grants ESP2017-89838, PGC2018-094773, PGC2018-102021, SEV2016-0588, SEV-2016-0597, and MDM-2015-0509, some of which include ERDF funds from the European Union. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya. Research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Program (FP7/2007- 2013), including ERC grant agreements 240672, 291329, and 306478. We acknowledge support from the Brazilian Instituto Nacional de Ciência e Tecnologia (INCT) e-Universe (CNPq grant 465376/2014-2). This paper has gone through internal review by the DES collaboration. This manuscript has been authored by the Fermi Research Alliance, LLC under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics.
- Published
- 2020
- Full Text
- View/download PDF
47. Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). VIII. A less biased view of the early co-evolution of black holes and host galaxies
- Author
-
Yoichi Tamura, Soh Ikarashi, Tohru Nagao, Kotaro Kohno, Takeo Minezaki, Masatoshi Imanishi, Takuma Izumi, Ji-Jia Tang, John D. Silverman, Michael A. Strauss, Nobunari Kashikawa, Kouichiro Nakanishi, Yuichi Harikane, Yoshiki Toba, Yoshiki Matsuoka, Yoshihiro Ueda, Seiji Fujimoto, Chien-Hsiu Lee, Hideki Umehata, Yasuhiro Hashimoto, Masafusa Onoue, Akio Taniguchi, Tomotsugu Goto, Jenny E. Greene, Kazushi Iwasawa, Hikari Shirakata, Daisuke Iono, and Astronomy
- Subjects
Stellar mass ,Astrophysics::High Energy Astrophysical Phenomena ,REDSHIFT ,FOS: Physical sciences ,Z-GREATER-THAN-5.7 QUASARS ,galaxies: starburst ,PHYSICAL MODEL ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Bulge ,galaxies: high-redshift ,quasars: general ,0103 physical sciences ,STAR-FORMING GALAXIES ,Astrophysics::Solar and Stellar Astrophysics ,DUST EMISSION ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Physics ,Supermassive black hole ,INTERSTELLAR-MEDIUM ,010308 nuclear & particles physics ,quasars: supermassive black holes ,Sigma ,Astronomy and Astrophysics ,Quasar ,Astrophysics - Astrophysics of Galaxies ,Redshift ,Galaxy ,C II EMISSION ,MOLECULAR GAS ,Black hole ,Space and Planetary Science ,TO 6 QUASARS ,Astrophysics of Galaxies (astro-ph.GA) ,DIGITAL SKY SURVEY ,galaxies: ISM - Abstract
We present ALMA [CII] line and far-infrared (FIR) continuum observations of three $z > 6$ low-luminosity quasars ($M_{\rm 1450} > -25$) discovered by our Subaru Hyper Suprime-Cam (HSC) survey. The [CII] line was detected in all three targets with luminosities of $(2.4 - 9.5) \times 10^8~L_\odot$, about one order of magnitude smaller than optically luminous ($M_{\rm 1450} \lesssim -25$) quasars. The FIR continuum luminosities range from $< 9 \times 10^{10}~L_\odot$ (3$��$ 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 [CII]/FIR luminosity ratios similar to local star-forming galaxies. Using the [CII]-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 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., 19 pages, 11 figures, 4 tables. Accepted for publication in Publications of the Astronomical Society of Japan (PASJ)
- Published
- 2019
48. Imaging extended emission-line regions of obscured AGN with the Subaru Hyper Suprime-Cam Survey
- Author
-
Sean D. Johnson, Alisabeth A Marsteller, Michael A. Strauss, Ai-Lei Sun, Yoshiki Matsuoka, Nadia L. Zakamska, Andy D. Goulding, Song Huang, Yoshiki Toba, Tohru Nagao, Jenny E. Greene, and Toshihiro Kawaguchi
- Subjects
Physics ,Active galactic nucleus ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,media_common.quotation_subject ,Doubly ionized oxygen ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Photoionization ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Redshift ,Spectral line ,Space and Planetary Science ,Sky ,Astrophysics of Galaxies (astro-ph.GA) ,Excited state ,0103 physical sciences ,Emission spectrum ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,media_common - Abstract
Narrow-line regions excited by active galactic nuclei (AGN) are important for studying AGN photoionization and feedback. Their strong [O III] lines can be detected with broadband images, allowing morphological studies of these systems with large-area imaging surveys. We develop a new technique to reconstruct the [O III] images using the Subaru Hyper Suprime-Cam (HSC) Survey aided with spectra from the Sloan Digital Sky Survey (SDSS). The technique involves a careful subtraction of the galactic continuum to isolate emission from the [O III]$\lambda$5007 and [O III]$\lambda$4959 lines. Compared to traditional targeted observations, this technique is more efficient at covering larger samples with less dedicated observational resources. We apply this technique to an SDSS spectroscopically selected sample of 300 obscured AGN at redshifts 0.1 - 0.7, uncovering extended emission-line region candidates with sizes up to tens of kpc. With the largest sample of uniformly derived narrow-line region sizes, we revisit the narrow-line region size-luminosity relation. The area and radii of the [O III] emission-line regions are strongly correlated with the AGN luminosity inferred from the mid-infrared (15 $\mu$m rest-frame) with a power-law slope of $0.62^{+0.05}_{-0.06} \pm 0.10$ (statistical and systemic errors), consistent with previous spectroscopic findings. We discuss the implications for the physics of AGN emission-line region and future applications of this technique, which should be useful for current and next-generation imaging surveys to study AGN photoionization and feedback with large statistical samples., Comment: 20 pages, 13 figures, MNRAS submitted
- Published
- 2018
49. Optical Spectroscopy of Dual Quasar Candidates from the Subaru HSC-SSP program
- Author
-
Masami Ouchi, Tohru Nagao, Knud Jahnke, Michael A. Strauss, Andy D. Goulding, Yoshiaki Ono, Nao Suzuki, Tilman Hartwig, Kazushi Iwasawa, Toshihiro Kawaguchi, Joseph F. Hennawi, Kotaro Kohno, Naoki Yasuda, Yuichi Matsuda, John D. Silverman, Yoshiaki Taniguchi, Yoshiki Toba, Junyao Li, J. Xavier Prochaska, Yoshihiro Ueda, Issha Kayo, Nobunari Kashikawa, Masamune Oguri, Masatoshi Imanishi, Xuheng Ding, Yoshiki Matsuoka, Hyewon Suh, Masafusa Onoue, Lalitwadee Kawinwanichakij, Khee-Gan Lee, Kazuhiro Shimasaku, Shenli Tang, Malte Schramm, Kohei Ichikawa, Ministry of Education, Culture, Sports, Science and Technology (Japan), Toray Science Foundation, Japan Science and Technology Agency, Princeton University, and Kavli Institute for Particle Astrophysics and Cosmology
- Subjects
Physics ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Quasar ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,DUAL (cognitive architecture) ,Astrophysics - Astrophysics of Galaxies ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,Astrophysics::Solar and Stellar Astrophysics ,Double quasars ,Spectroscopy ,Quasars ,Astrophysics::Galaxy Astrophysics - Abstract
Tang, S., et al., We report on a spectroscopic program to search for dual quasars using Subaru Hyper Suprime-Cam (HSC) images of SDSS quasars, which represent an important stage during galaxy mergers. Using Subaru/FOCAS and Gemini-N/GMOS, we identify three new physically associated quasar pairs having projected separations less than 20 kpc, out of 26 observed candidates. These include the discovery of the highest-redshift (z = 3.1) quasar pair with a separation, Funding was contributed by the FIRST program from the Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU, KEK, ASIAA, and Princeton University
- Published
- 2021
50. The Sizes of Quasar Host Galaxies in the Hyper Suprime-Cam Subaru Strategic Program
- Author
-
Yoshiki Toba, Kohei Inayoshi, Yongquan Xue, Xuheng Ding, Yoshiki Matsuoka, John D. Silverman, Junyao Li, Michael A. Strauss, Tohru Nagao, Andy D. Goulding, Lalitwadee Kawinwanichakij, M. Schramm, Hassen M. Yesuf, and Simon Birrer
- Subjects
Physics ,Supermassive black hole ,Active galactic nucleus ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Quasar ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Astrophysics - Astrophysics of Galaxies ,01 natural sciences ,Galaxy ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Host (network) ,Astrophysics::Galaxy Astrophysics - Abstract
The relationship between quasars and their host galaxies provides clues on how supermassive black holes (SMBHs) and massive galaxies are jointly assembled. To elucidate this connection, we measure the structural and photometric properties of the host galaxies of ~5000 SDSS quasars at 0.2, Comment: 34 pages, 22 figures, 3 tables, resubmitted to ApJ after addressing referee's comments; catalog will be available after the paper is published
- Published
- 2021
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.