NOAO >   Observing Info >   Approved Programs >   2017B-0142

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Program Information for 2017B-0142


PI: Xiaohui Fan, U. of Arizona, fan@as.arizona.edu
Address: Department of Astronomy and Steward Observatory, 933 NORTH CHERRY AVENUE, TUCSON, AZ 85721-0065 USA

CoI: Feige Wang, Peking University
CoI: Jan-Torge Schindler, U. of Arizona
CoI: Ian McGreer, U. of Arizona
CoI: Zheng Cai, UC Santa Cruz
CoI: Xuebing Wu, The Kavli Institute for Astronomy and Astrophysics
CoI: Jinyi Yang, Peking University
CoI: Simon Dye, Nottingham University
CoI: Richard Green, U. of Arizona
CoI: Joseph Findlay, U. of Wyoming

Title: Near-IR Spectroscopic Observations of Two Newly Discovered Luminous Quasars at z>6.5

Abstract: Luminous quasars at z>6 provide direct probes of the evolution of supermassive black holes (BHs) and the intergalactic medium (IGM) at early cosmic time. More than 100 quasars have been discovered at z~6. Detections of such objects indicate the existence of billion solar mass BHs merely a few hundred Myrs after the Big Bang. Absorption spectra of the highest redshift quasars reveal complete Gunn-Peterson absorption with a rapid increase in the IGM neutral fraction, marking the end of the reionization epoch at z>6. However, only one quasar was public known at z>7 and a handful quasar at z>6.5. Recently, we discovered two luminous quasars at redshift z=6.9 and z=6.7 using the near-IR imaging data from UKIRT Hemisphere Survey (UHS). These two quasars are the second and sixth most distant quasars known and are about one magnitude brighter than the other three known quasars at 6.7<z<7.0. We propose to use Gemini/GNIRS to obtain high quality near-IR spectra of these two newly discovered luminous quasars. The proposed observations will provide crucial measurements of BH masses, Eddington ratios and chemical abundances in the quasar broad line regions. MgII emission line will also provide accurate, unbiased systemic redshifts of the quasar systems, which is the key to plan spectroscopic follow-up observations in (sub)mm wavelength to study the earliest SMBH/galaxy co-evolution, as well as to anchor the measurements of the quasar near zone sizes and possible damping wing profiles through high resolution optical spectroscopy to constrain the history of cosmic reionization. In addition, the high quality GNIRS spectra will also allow us to identify high redshift intervening metal absorbers.

Program Type: Standard/Extragalactic

Scheduled Nights:
Run 1 (2017B):  GEM-NQ/GNIRS -- 14.2hrs band 1 (GN-2017B-Q-9)


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