The SCUBA-2 850 $\mu m$ follow-up of WISE-selected, luminous dust-obscured quasars

TL;DR

This study presents SCUBA-2 850 μm follow-up observations of 10 Hot DOGs, revealing their extreme luminosities, dust properties, and dense environments, supporting their role as transitional, dust-obscured quasars.

Contribution

First SCUBA-2 850 μm follow-up of Hot DOGs, providing insights into their IR luminosities, dust temperatures, and environmental density, highlighting their transitional quasar nature.

Findings

Most Hot DOGs have IR luminosities >10^14 L_sun.

Cold dust contributes 8-24% to total IR luminosity.

Hot DOGs are found in dense environments.

Abstract

Hot dust-obscured galaxies (Hot DOGs) are a new population recently discovered in the \wise All-Sky survey. Multiwavelength follow-up observations suggest that they are luminous, dust-obscured quasars at high redshift. Here we present the JCMT SCUBA-2 850 $\mu m$ follow-up observations of 10 Hot DOGs. Four out of ten Hot DOGs have been detected at $>3\sigma$ level. Based on the IR SED decomposition approach, we derive the IR luminosities of AGN torus and cold dust components. Hot DOGs in our sample are extremely luminous with most of them having $L_{\rm IR}^{\rm tot}>10^{14} L_\odot$. The torus emissions dominate the total IR energy output. However, the cold dust contribution is still non-negligible, with the fraction of the cold dust contribution to the total IR luminosity $(\sim 8-24\%)$ being dependent on the choice of torus model. The derived cold dust temperatures in Hot DOGs are comparable to those in UV bright quasars with similar IR luminosity, but much higher than those in SMGs. Higher dust temperatures in Hot DOGs may be due to the more intense radiation field caused by intense starburst and obscured AGN activities. Fourteen and five submillimeter serendipitous sources in the 10 SCUBA-2 fields around Hot DOGs have been detected at $>3\sigma$ and $>3.5\sigma$ levels, respectively. By estimating their cumulative number counts, we confirm the previous argument that Hot DOGs lie in dense environments. Our results support the scenario in which Hot DOGs are luminous, dust-obscured quasars lying in dense environments, and being in the transition phase between extreme starburst and UV-bright quasars.