Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). V. Quasar Luminosity Function and Contribution to Cosmic Reionization at z = 6
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). V. Quasar Luminosity Function and Contribution to Cosmic Reionization at z = 6
复制标题
DOI：
10.3847/1538-4357/aaee7a
复制
发表时间：
2018-11
期刊：
影响因子：
--
通讯作者：
Y. Matsuoka;M. Strauss;N. Kashikawa;M. Onoue;K. Iwasawa;Ji-Jia Tang;Chien-Hsiu Lee;M. Imanishi;T. Nagao;M. Akiyama;N. Asami;J. Bosch;H. Furusawa;T. Goto;J. Gunn;Y. Harikane;H. Ikeda;T. Izumi;T. Kawaguchi;N. Kato;S. Kikuta;K. Kohno;Y. Komiyama;R. Lupton;T. Minezaki;S. Miyazaki;H. Murayama;M. Niida;A. Nishizawa;Akatoki Noboriguchi;M. Oguri;Y. Ono;M. Ouchi;P. Price;H. Sameshima;A. Schulze;H. Shirakata;J. Silverman;N. Sugiyama;Philip J. Tait;M. Takada;T. Takata;Masayuki Tanaka;Y. Toba;Y. Utsumi;Shiang‐Yu Wang;T. Yamashita
中科院分区：
文献类型：
--
作者：
Y. Matsuoka;M. Strauss;N. Kashikawa;M. Onoue;K. Iwasawa;Ji-Jia Tang;Chien-Hsiu Lee;M. Imanishi;T. Nagao;M. Akiyama;N. Asami;J. Bosch;H. Furusawa;T. Goto;J. Gunn;Y. Harikane;H. Ikeda;T. Izumi;T. Kawaguchi;N. Kato;S. Kikuta;K. Kohno;Y. Komiyama;R. Lupton;T. Minezaki;S. Miyazaki;H. Murayama;M. Niida;A. Nishizawa;Akatoki Noboriguchi;M. Oguri;Y. Ono;M. Ouchi;P. Price;H. Sameshima;A. Schulze;H. Shirakata;J. Silverman;N. Sugiyama;Philip J. Tait;M. Takada;T. Takata;Masayuki Tanaka;Y. Toba;Y. Utsumi;Shiang‐Yu Wang;T. Yamashita
我们提出了新的测量的类星体光度函数（LF）在z 106在一个前所未有的广泛的范围内的休息帧紫外光度M1450从-30到-22马格。这是第五次在一系列出版物从斯巴鲁高z探测低光度类星体（SHELLQs）项目，利用深多波段成像数据产生的超级Suprime-Cam斯巴鲁战略计划调查。LF是用110个5.7 ≤ z ≤ 6.5的类星体的完整样本计算的，其中包括斯隆数字巡天和加拿大-法国-夏威夷类星体巡天发现的48个650 ° 2以上的SHELLQ类星体和63个更亮的类星体（包括一个重叠天体）。这是迄今为止z ≥ 6类星体中最大的样本，具有定义良好的选择函数，这使我们能够在LF的暗端检测到显着的扁平化。一个双幂律函数拟合样本得到一个暗端斜率、一个亮端斜率、一个突变星等和一个特征空间密度Gpc−3 mag−1。在−18 < M1450 < −30 mag的范围内对这个最佳拟合模型进行积分，类星体在z = 6.0时以s−1 Mpc−3的速率发射电离光子。这还不到维持星系际介质电离所需的临界速率的10%，这表明类星体不是宇宙再电离的主要贡献者。
We present new measurements of the quasar luminosity function (LF) at z ∼ 6 over an unprecedentedly wide range of the rest-frame ultraviolet luminosity M1450 from −30 to −22 mag. This is the fifth in a series of publications from the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which exploits the deep multiband imaging data produced by the Hyper Suprime-Cam Subaru Strategic Program survey. The LF was calculated with a complete sample of 110 quasars at 5.7 ≤ z ≤ 6.5, which includes 48 SHELLQs quasars discovered over 650 deg2 and 63 brighter quasars discovered by the Sloan Digital Sky Survey and the Canada–France–Hawaii Quasar Survey (including one overlapping object). This is the largest sample of z ∼ 6 quasars with a well-defined selection function constructed to date, which has allowed us to detect significant flattening of the LF at its faint end. A double power-law function fit to the sample yields a faint-end slope , a bright-end slope , a break magnitude , and a characteristic space density Gpc−3 mag−1. Integrating this best-fit model over the range −18 < M1450 < −30 mag, quasars emit ionizing photons at the rate of s−1 Mpc−3 at z = 6.0. This is less than 10% of the critical rate necessary to keep the intergalactic medium ionized, which indicates that quasars are not a major contributor to cosmic reionization.