Hyperluminous reddened broad-line quasars at z ∼ 2 from the VISTA Hemisphere Survey and WISE all-sky survey

Abstract

Abstract We present the first sample of spectroscopically confirmed heavily reddened broad-line quasars selected using the new near-infrared VISTA Hemisphere Survey and Wide-field Infrared Survey Explorer (WISE) all-sky survey. Observations of four candidates with (J − K) > 2.5 and K ≤ 16.5 over ∼180 deg2 lead to confirmation that two are highly dust-reddened broad-line Type 1 quasars at z ∼ 2. The typical dust extinctions are AV ∼ 2–2.5 mag. We measure black hole masses of ∼109 M⊙ and extinction-corrected bolometric luminosities of ∼1047 erg s−1, making them some of the brightest Type 1 quasars currently known. Despite this, these quasars lie well below the detection limits of wide-field optical surveys like the Sloan Digital Sky Survey (SDSS) with iAB > 22. We also present WISE photometry at 3–22 μm, for our full sample of spectroscopically confirmed reddened quasars including those selected from the UKIDSS Large Area Survey. We demonstrate that the rest-frame infrared spectral energy distributions of these reddened quasars are similar to ultraviolet-luminous Type 1 quasars with significant hot dust emission and starburst quasar hosts like Mrk 231. The average 12-μm flux density of our reddened quasars is similar to that of the recently discovered hyperluminous infrared galaxy (HyLIRG) WISE 1814+3412 (z = 2.452) at similar redshifts, with two of our reddened quasars also having comparable 22-μm flux densities to this extreme HyLIRG. These optically faint, heavily reddened broad-line quasars are therefore among the most mid-infrared-luminous galaxies at z ∼ 2, now being discovered using WISE.