Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XI. Proximity Zone Analysis for Faint Quasar Spectra at z ∼ 6
We present measurements of the size of the quasar proximity zone (R) for 11 low-luminosity (-26.16 ≤ M ≤ -22.83) quasars at z ∼ 6, discovered by the Subaru High-z Exploration of Low-Luminosity Quasars project. Our faint quasar sample expands the R measurement down to M = -22.83 mag, where more commo...
| Autores: | , , , , , , , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión enviada para evaluación y publicación |
| Fecha de publicación: | 2020 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/235498 |
| Acesso em linha: | http://hdl.handle.net/10261/235498 |
| Access Level: | acceso abierto |
| Palavra-chave: | Dark ages Reionization First stars: Quasars: absorption lines |
| Resumo: | We present measurements of the size of the quasar proximity zone (R) for 11 low-luminosity (-26.16 ≤ M ≤ -22.83) quasars at z ∼ 6, discovered by the Subaru High-z Exploration of Low-Luminosity Quasars project. Our faint quasar sample expands the R measurement down to M = -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 [C II] 158 μm or Mg II λ2798 emission lines. We also update the R measurements for 26 luminous quasars presented in Eilers et al. by using the latest systemic redshift results. The luminosity dependence on R is found to be consistent with the theoretical prediction assuming a highly ionized intergalactic medium. We find a shallow redshift evolution of the luminosity-corrected R, R (R µ (1 + z)±) over 5.8 ≤ z ≤ 6.6. This trend is steeper than that of Eilers et al., but significantly shallower than those of the earlier studies. Our results suggest that R is insensitive to the neutral fraction of the universe at z ∼ 6. Four quasars show exceptionally small R (≤0.90 proper Mpc), which could be the result of their young age (<10 yr) in the reionization epoch, though statistics on this are still scarce. |
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