Details

Autor(en) / Beteiligte

• Wang, Feige
• Fan, Xiaohui
• Yang, Jinyi
• Wu, Xue-Bing
• Yang, Qian
• Bian, Fuyan
• McGreer, Ian D.
• Li, Jiang-Tao
• Li, Zefeng
• Ding, Jiani
• Dey, Arjun
• Dye, Simon
• Findlay, Joseph R.
• Green, Richard
• James, David
• Jiang, Linhua
• Lang, Dustin
• Lawrence, Andy
• Myers, Adam D.
• Ross, Nicholas P.
• Schlegel, David J.
• Shanks, Tom

Titel

First Discoveries of z > 6 Quasars with the DECam Legacy Survey and UKIRT Hemisphere Survey

Ist Teil von

• The Astrophysical journal, 2017-04, Vol.839 (1), p.27

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2017

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• We present the first discoveries from a survey of z 6 quasars using imaging data from the DECam Legacy Survey (DECaLS) in the optical, the UKIRT Deep Infrared Sky Survey (UKIDSS) and a preliminary version of the UKIRT Hemisphere Survey (UHS) in the near-IR, and ALLWISE in the mid-IR. DECaLS will image 9000 deg2 of sky down to zAB ∼ 23.0, and UKIDSS and UHS will map the northern sky at 0 < decl. < +60°, reaching JVEGA ∼ 19.6 (5- ). The combination of these data sets allows us to discover quasars at redshift z 7 and to conduct a complete census of the faint quasar population at z 6. In this paper, we report on the selection method of our search, and on the initial discoveries of two new, faint z 6 quasars and one new z = 6.63 quasar in our pilot spectroscopic observations. The two new z ∼ 6 quasars are at z = 6.07 and z = 6.17 with absolute magnitudes at rest-frame wavelength 1450 being M1450 = −25.83 and M1450 = −25.76, respectively. These discoveries suggest that we can find quasars close to or fainter than the break magnitude of the Quasar Luminosity Function (QLF) at z 6. The new z = 6.63 quasar has an absolute magnitude of M1450 = −25.95. This demonstrates the potential of using the combined DECaLS and UKIDSS/UHS data sets to find z 7 quasars. Extrapolating from previous QLF measurements, we predict that these combined data sets will yield ∼200 z ∼ 6 quasars to zAB < 21.5, ∼1000 z ∼ 6 quasars to zAB < 23, and ∼30 quasars at z > 6.5 to JVEGA < 19.5.