J1406+0102: Dust Obscured Galaxy Hiding Super Eddington Accretion System with Bright Radio Emission

Abstract

Recent high-$z$ quasar observations strongly indicate that super-Eddington accretion is a crucial phase to describe the presence of supermassive black holes (SMBHs) with $M_{\mathrm{BH}}\gtrsim 10^9{M}_{\odot }$ at $z\gtrsim 7$. Motivated by theoretical predictions that the super-Eddington phase efficiently produces outflows and jets bright in radio bands, we identify a super-Eddington radio-loud dust-obscured galaxy (DOG) J1406+0102 at $z=0.2367$. This source is discovered by cross-matching the infrared-bright DOGs of Nobriguchi et al. (2019) with the VLA/FIRST 1.4 GHz radio survey data and the SDSS optical spectral catalog. J1406+0102 shows broad components in the Balmer lines, and by assuming that those lines are from the broad line region, they give BH mass estimations of $\log (M_{\mathrm{BH}}/M_{\odot })=7.30\pm 0.25$. Combined with an AGN luminosity of $\log (L_{\mathrm{bol},[\mathrm{OIII}]}/\mathrm{erg}{\mathrm{s}}^{-1})=45.91\pm 0.38$ estimated from the intrinsic [OIII] luminosity, this implies a super-Eddington accretion rate of ${\lambda }_{\mathrm{Edd}}\simeq 3$. We show that 1) J1406+0102 shows strong AGN feedback, with the [OIII] outflow velocity exceeds the escape velocity of the host galaxy halo and a kinetic efficiency of $\approx$ 8%, sufficient to quench the host galaxy; 2) its expected growth trajectory places it on an over-massive BH track; and 3) if representative of radio-loud DOGs, such sources can contribute significantly to the high-energy ($\gtrsim$ 100 TeV) cosmic neutrino background.

14 pages, 6 figures, accepted for publication in ApJ