A5019041591- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Scientific Research and Discoveries
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- CCD and CMOS Imaging Sensors
- Dark Matter and Cosmic Phenomena
- Big Data Technologies and Applications
- Anomaly Detection Techniques and Applications
- Data Analysis with R
- Data Management and Algorithms
- Astronomical Observations and Instrumentation
- Video Analysis and Summarization
- Scientific Computing and Data Management
- Web Data Mining and Analysis
The University of Tokyo
2020-2024
Abstract We present the quasar luminosity function (LF) at z = 7, measured with 35 spectroscopically confirmed quasars 6.55 < 7.15. The sample of 22 from Subaru High- Exploration Low-Luminosity Quasars (SHELLQs) project, combined 13 brighter in literature, covers an unprecedentedly wide range rest-frame ultraviolet magnitudes over −28 M 1450 −23. found that binned LF flattens significantly toward faint end populated by SHELLQs quasars. A maximum likelihood fit to a double power-law model...
Abstract We present the spectroscopic discovery of 69 quasars at 5.8 < z 7.0, drawn from Hyper Suprime-Cam (HSC) Subaru Strategic Program (SSP) imaging survey data. This is 16th publication High- Exploration Low-Luminosity Quasars (SHELLQs) project, and it completes identification all but faintest candidates (i.e., i -band dropouts with AB 24 y detections, 24) Bayesian quasar probability <?CDATA ${P}_{Q}^{B}\gt 0.1$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract We present, for the first time, dark matter halo (DMH) mass measurement of quasars at z ∼ 6 based on a clustering analysis 107 quasars. Spectroscopically identified are homogeneously extracted from Hyper Suprime-Cam Strategic Survey Program wide layer over 891 deg 2 . evaluate strength by three different autocorrelation functions: projected correlation function, angular and redshift–space function. The DMH is evaluated as <?CDATA ${5.0}_{-4.0}^{+7.4}\times...
The large opacity fluctuations in the $z > 5.5$ Ly$\alpha$ forest may indicate inhomogeneous progress of reionization. To explain observed scatter effective optical depth ($\tau_{\rm eff}$) intergalactic medium (IGM), fluctuation UV background ($\Gamma$ model) or IGM gas temperature ($T$ have been proposed, which predict opposite correlations between $\tau_{\rm eff}$ and galaxy density. In order to address model can eff}$, we search for emitters (LAEs) around two (J1137+3549 J1602+4228)...
Abstract Spatial inhomogeneity is one of the important features for understanding reionization process; however, it has not yet been fully quantified. To map this inhomogeneous distribution, we simultaneously detect Ly α emitters (LAEs) and Lyman-break galaxies (LBGs) at z ∼ 6.6 from Subaru/Hyper Suprime-Cam large-area (∼1.5 deg 2 = 34,000 cMpc ) deep survey. We estimate neutral fraction, x HI , observed number density ratio LAEs to LBGs, n (LAE)/ (LBG), using numerical radiative transfer...
This study aims at identifying luminous quasars $z>5.7$ among X-ray-selected sources in the eROSITA Final Equatorial-Depth Survey (eFEDS) order to place a lower limit on black hole accretion well into epoch of re-ionisation. We confirm low significance detection with previously known, optically faint $z=6.56$ quasar from Subaru High-z Exploration Low-luminosity Quasars (SHELLQs) survey. obtained pointed follow-up observation source Chandra X-ray telescope detection. Using new near-infrared...
Abstract We report the discovery of two quasars at a redshift z = 6.05 in process merging. They were serendipitously discovered from deep multiband imaging data collected by Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. The quasars, HSC J121503.42−014858.7 (C1) and J121503.55−014859.3 (C2), both have luminous (>10 43 erg s −1 ) Ly α emission with clear broad component (full width half maximum >1000 km ). rest-frame ultraviolet (UV) absolute magnitudes are M 1450 − 23.106 ±...
We present the quasar luminosity function (LF) at $z = 7$, measured with 35 spectroscopically confirmed quasars $6.55 < z 7.15$. The sample of 22 from Subaru High-$z$ Exploration Low-Luminosity Quasars (SHELLQs) project, combined 13 brighter in literature, covers an unprecedentedly wide range rest-frame ultraviolet magnitudes over $-28 M_{1450} -23$. found that binned LF flattens significantly toward faint end populated by SHELLQs quasars. A maximum likelihood fit to a double power-law...
We present a comparison of the spatial distributions Ly$\alpha$ emitters (LAEs) and massive star-forming quiescent galaxies (SFGs QGs) at $2<z<4.5$. use photometric redshift catalog to select SFGs QGs LAE from intermediate/narrow bands obtained Subaru Telescope Isaac-Newton in Cosmic Evolution Survey (COSMOS). derive auto-/cross- correlation signals SFGs, QGs, LAEs, galaxy overdensity position them. Whereas cross-correlation are explained solely by their halo mass differences, those LAEs...
Protoclusters are high-$z$ overdense regions that will evolve into clusters of galaxies by $z=0$, making them ideal for studying galaxy evolution expected to be accelerated environmental effects. However, it has been challenging identify protoclusters beyond $z=3$ only photometry due large redshift uncertainties, hindering statistical study. To tackle the issue, we develop a new deep-learning-based protocluster detection model, PCFNet, which considers as point cloud. detect at $z\sim4$ using...
Abstract Protoclusters are high- z overdense regions that will evolve into clusters of galaxies by = 0, making them ideal for studying galaxy evolution expected to be accelerated environmental effects. However, it has been challenging identify protoclusters beyond 3 only photometry due large redshift uncertainties hindering statistical study. To tackle the issue, we develop a new deep-learning-based protocluster detection model, PCFNet, which considers as point cloud. detect at ∼ 4 using...
Abstract The Lyα emission line is a characteristic feature found in high-z galaxies, serving as probe of cosmic reionization. While previous works present various correlations between and physical properties host it still unclear which characteristics predominantly determine the emission. In this study, we introduce neural network approach to simultaneously handle multiple galaxies. neural-network-based prediction model that identifies emitters (LAEs) from six properties: star formation rate...
The Ly$\alpha$ emission line is a characteristic feature found in high-$z$ galaxies, serving as probe of cosmic reionization. While previous works present various correlations between and physical properties host it still unclear which characteristics predominantly determine the emission. In this study, we introduce neural network approach to simultaneously handle multiple galaxies. neural-network-based prediction model that identifies emitters (LAEs) from six properties: star formation rate...
Abstract We present measurements of the size quasar proximity zone ( R p ) for 11 low-luminosity <?CDATA $-26.16\leqslant {M}_{1450}\leqslant -22.83$?> quasars at z ∼ 6, discovered by Subaru High- Exploration Low-Luminosity Quasars project. Our faint sample expands measurement down to ${M}_{1450}=-22.83$?> mag, where more common populations dominate epoch. restrict whose systemic redshifts have been precisely measured [C ii ] 158 μ m or Mg λ 2798 emission lines. also update 26 luminous...
We present, for the first time, dark matter halo (DMH) mass measurement of quasars at $z\sim6$ based on a clustering analysis 107 quasars. Spectroscopically identified are homogeneously extracted from HSC-SSP wide layer over $891\,\mathrm{deg^2}$. evaluate strength by three different auto-correlation functions: projected correlation function, angular and redshift-space function. The DMH is evaluated as $5.0_{-4.0}^{+7.4}\times10^{12}\,h^{-1}M_\odot$ with bias parameter $b=20.8\pm8.7$ other...
We aim to find out the reason why there exists an anisotropic HI absorption around quasars; i.e., environments quasars are highly biased toward producing strong in transverse direction while a significant deficit of within few Mpc along line-of-sight. The most plausible explanation for this opposite trend is that shadowed from quasar UV radiation due dust torus. However, critical weakness idea we have no information on inclination angle our sightline relative In study, examine with broad...
The large opacity fluctuations in the $z > 5.5$ Ly$α$ forest may indicate inhomogeneous progress of reionization. To explain observed scatter effective optical depth ($τ_{\rm eff}$) intergalactic medium (IGM), fluctuation UV background ($Γ$ model) or IGM gas temperature ($T$ have been proposed, which predict opposite correlations between $τ_{\rm eff}$ and galaxy density. In order to address model can eff}$, we search for emitters (LAEs) around two (J1137+3549 J1602+4228) quasar sightlines...