"Extreme Red Quasars in SDSS3-BOSS"

 

ABSTRACT:

 

Dust-reddened quasars are believed to mark a early stage of massive galaxy evolution where declining star formation rates are accompanied by blowouts of gas and dust that provide our first visible views of a luminous central AGN. The recent Baryon Oscillation Spectroscopy Survey (BOSS) of SDSS-III discovered many more faint quasars with higher redshifts and redder colors than any previous large survey. I will describe studies that combine BOSS spectra with SDSS and Wide-Field Infrared Survey Explorer (WISE) photometry of nearly 100,000 z > 2 quasars to identify red quasars and characterize trends in the quasar properties with reddening. We find a number of strong trends consistent with a young evolution stage. For example, red quasars are 5 to 8 times more likely to have all varieties of "intrinsic" absorption lines in their spectra, including broad absorption lines (BALs) and their narrower cousins (mini-BALs) that identify strong quasar-driven outflows. 

 

Red quasars also tend to have emission line spectra resembling narrow-line Seyfert 1s, which are believed to have high accretion rates (L/Ledd). Perhaps most surprising is a new population of extreme red quasars (ERQs), selected via rest-frame UV to near-IR colors similar to Dust Obscured Galaxies (DOGs), that we find to have uniquely exotic emission line properties such as highly blueshifted CIV emission lines and the broadest and most blueshifted [OIII] lines ever recorded (with FWHMs and blue wings reaching 5000 km/s). These extreme [OIII] lines strongly favor a unique evolution stage involving galaxy-scale blowouts.