Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). XI. Proximity Zone Analysis for Faint Quasar Spectra at z~6

Abstract

We present measurements of the size of the quasar proximity zone ($R_p$) for eleven low-luminosity ($-26.16\le M_{1450}\le -22.83$) quasars at $z\sim 6$, discovered by the Subaru High-$z$ Exploration of Low-Luminosity Quasars project (SHELLQs). Our faint quasar sample expands the $R_p$ measurement down to $M_{1450}=-22.83$ mag, where more common quasar populations dominate at the epoch. We restrict the sample to quasars whose systemic redshifts have been precisely measured by [CII] 158 $\mu$m or MgII $\lambda$2798 emission lines. We also update the $R_p$ measurements for 26 luminous quasars presented in Eilers et al. (2017)(arXiv:1703.02539) by using the latest systemic redshift results. The luminosity dependence on $R_p$ is found to be consistent with the theoretical prediction assuming highly ionized intergalactic medium. We find a shallow redshift evolution of the luminosity-corrected $R_p$, $R_{p,\mathrm{corr}}^{-25}$ ($R_{p,\mathrm{corr}}^{-25}\propto (1+z{)}^{-3.79\pm 1.72}$) over $5.8\lesssim z\lesssim 6.6$. This trend is steeper than that of Eilers et al. (2017) but significantly shallower than those of the earlier studies. Our results suggest that $R_{p,\mathrm{corr}}$ is insensitive to the neutral fraction of the universe at $z\sim 6$. Four quasars show exceptionally small $R_{p,\mathrm{corr}}^{-25}$ ($\lesssim 0.90$ proper Mpc), which could be the result of their young age ($<10^4$ yr) in the reionization epoch, though statistics is still small.

arXiv comment14 pages, 8 figures, Accepted for publication in ApJ

References in corpus (53)

• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Planck 2013 results. XVI. Cosmological parameters
• A luminous quasar at a redshift of z = 7.085
• Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z ~ 6 Quasars II: A Sample of 19 Quasars
• An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5
• An Empirical Ultraviolet Template for Iron Emission in Quasars as Derived from I Zw 1
• Evidence of patchy hydrogen reionization from an extreme Ly$\alpha$ trough below redshift six
• Star Formation and Gas Kinematics of Quasar Host Galaxies at z~6: New insights from ALMA
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• Eddington-limited accretion and the black hole mass function at redshift 6
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• An ALMA [CII] survey of 27 quasars at z>5.94
• Molecular Gas in Redshift 6 Quasar Host Galaxies
• Gemini Near-infrared Spectroscopy of Luminous z~6 Quasars: Chemical Abundances, Black Hole Masses, and MgII Absorption
• Evolution of the AGN UV luminosity function from redshift 7.5
• Black hole masses and enrichment of z ~ 6 SDSS quasars
• Evidence for non-evolving FeII/MgII ratios in rapidly accreting z~6 QSOs
• Subaru high-z exploration of low-luminosity quasars (SHELLQs). I. Discovery of 15 quasars and bright galaxies at 5.7 < z < 6.9
• Gemini GNIRS near-infrared spectroscopy of 50 quasars at z>~5.7
• Exploring Reionization-Era Quasars III: Discovery of 16 Quasars at $6.4\lesssim z\lesssim 6.9$ with DESI Legacy Imaging Surveys and UKIRT Hemisphere Survey and Quasar Luminosity Function at $z\sim 6.7$
• A Survey of z~6 Quasars in the SDSS Deep Stripe. II. Discovery of Six Quasars at z_{AB}>21
• Discovery of the First Low-Luminosity Quasar at z > 7
• The identification of z-dropouts in Pan-STARRS1: three quasars at 6.5<z<6.7
• The nature and evolution of the highly ionized near-zones in the absorption spectra of z~6 quasars
• The Detectability of High Redshift Lyman Alpha Emission Lines Prior to the Reionization of the Universe
• The Opacity of the Intergalactic Medium Measured Along Quasar Sightlines at $z\sim 6$
• Quasar Strömgren Spheres Before Cosmological Reionization
• Star formation rate and dynamical mass of 10^8 solar mass black hole host galaxies at redshift 6
• Discovery of eight z ~ 6 quasars from Pan-STARRS1
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). II. Discovery of 32 Quasars and Luminous Galaxies at 5.7 < z < 6.8
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). IV. Discovery of 41 Quasars and Luminous Galaxies at 5.7 < z < 6.9
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). VI. Black Hole Mass Measurements of Six Quasars at 6.1<z<6.7
• Redshift 6.4 host galaxies of 10^8 solar mass black holes: low star formation rate and dynamical mass
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). X. Discovery of 35 Quasars and Luminous Galaxies at 5.7 $\le$ z $\le$ 7.0
• Eight new luminous z > 6 quasars selected via SED model fitting of VISTA, WISE and Dark Energy Survey Year 1 Observations
• A Principal Component Analysis of quasar UV spectra at z~3
• Ionization near-zones associated with quasars at z ~ 6
• The Subaru high-z quasar survey: discovery of faint z~6 quasars
• The REQUIEM Survey I: A Search for Extended Ly-Alpha Nebular Emission Around 31 z>5.7 Quasars
• 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
• Detecting and Characterizing Young Quasars I: Systemic Redshifts and Proximity Zones Measurements
• A wide dispersion in star formation rate and dynamical mass of 10^8 solar mass black hole host galaxies at redshift 6
• Predicting QSO Continua in the Ly Alpha Forest
• Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) III. Star formation properties of the host galaxies at $z\gtrsim 6$ studied with ALMA
• New Constraints on Quasar Evolution: Broad Line Velocity Shifts over $1.5\lesssim z\lesssim 7.5$
• Bright [CII] 158$\mu$m emission in a quasar host galaxy at $z=6.54$
• First Spectroscopic Study of a Young Quasar
• Time-dependent behaviour of quasar proximity zones at $z\sim 6$
• Double tidal disruptions in galactic nuclei
• Evidence for a pulsar wind nebula in the Type Ib-peculiar supernova SN 2012au
• Kiloparsec-Scale Simulations of Star Formation in Disk Galaxies III. Structure and Dynamics of Filaments and Clumps in Giant Molecular Clouds
• Truth or delusion? A possible gravitational lensing interpretation of the ultra-luminous quasar SDSS J010013.02+280225.8 at $z=6.30$

Cited by in corpus (13)

• The discovery of a highly accreting, radio-loud quasar at z=6.82
• Detecting and Characterizing Young Quasars II: Four Quasars at $z\sim 6$ with Lifetimes $<10^4$ years
• The need for obscured supermassive black hole growth to explain quasar proximity zones in the epoch of reionization
• The Distribution and Evolution of Quasar Proximity Zone Sizes
• The Assembly of Black Hole Mass and Luminosity Functions of High-redshift Quasars via Multiple Accretion Episodes
• New quasar proximity zone size measurements at $z\sim 6$ using the enlarged XQR-30 sample
• The physical origin for spatially large scatter of IGM opacity at the end of reionization: the IGM Ly$\alpha$ opacity-galaxy density relation
• X-ray emission from a rapidly accreting narrow-line Seyfert 1 galaxy at z=6.56
• Probing quasar lifetimes with proximate $21$-centimetre absorption in the diffuse intergalactic medium at redshifts $z\ge 6$
• Fading Light, Fierce Winds: JWST Snapshot of a Sub-Eddington Quasar at Cosmic Dawn
• Exploratory Study of Transverse Proximity Effect around BAL Quasars
• Euclid: Discovery of 31 new quasars at $6.6<z<7.8$
• The Contribution of AGN Accretion Disks to Hydrogen Reionization