Spectral Energy Distributions of Companion Galaxies to z ∼ 6 Quasars
Farina, E. P.
Venemans, B. P.
Strauss, M. A.
AffiliationUniv Arizona, Steward Observ
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PublisherIOP PUBLISHING LTD
CitationC. Mazzucchelli et al 2019 ApJ 881 163
RightsCopyright © 2019. The American Astronomical Society.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractMassive, quiescent galaxies are already observed at redshift z similar to 4, i.e., similar to 1.5 Gyr after the big bang. Current models predict them to be formed via massive, gas-rich mergers at z > 6. Recent ALMA observations of the cool gas and dust in z greater than or similar to 6 quasars have discovered [C II]- and far-infrared-bright galaxies adjacent to several quasars. In this work, we present sensitive imaging and spectroscopic follow-up observations, with HST/WFC3, Spitzer/IRAC, VLT/MUSE, Magellan/FIRE, and LBT/LUCI-MODS, of ALMA-detected, dust-rich companion galaxies of four quasars at z greater than or similar to 6, specifically acquired to probe their stellar content and unobscured star formation rate. Three companion galaxies do not show significant emission in the observed optical/IR wavelength range. The photometric limits suggest that these galaxies are highly dust-enshrouded, with unobscured star formation rates SFRUV < few M-circle dot yr(-1), and a stellar content of M-* < 10(10) M(circle dot)yr(-1). However, the companion to PJ167-13 shows bright rest-frame UV emission (F140W AB = 25.48). Its spectral energy distribution resembles that of a star-forming galaxy with a total SFR similar to 50 M-circle dot yr(-1) and M-* similar to 9 x 10(9) M-circle dot. All the companion sources are consistent with residing on the galaxy main sequence at z similar to 6. Additional, deeper data from future facilities, such as the James Webb Space Telescope, are needed in order to characterize these gas-rich sources in the first gigayear of cosmic history.
VersionFinal published version
SponsorsERC; National Science Foundation [AST-1614213]; ESO Telescopes at the La Silla Paranal Observatory [099.A-0682, 297.A-5054]; NSF [AST-9987045]; NSF Telescope System Instrumentation Program (TSIP); Ohio Board of Regents; Ohio State University Office of Research; NASA [NAS 5-26555, 14876]; NASA from the Space Telescope Science Institute