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 $\log (L_\mathrm{bol,[OIII]}/\mathrm{erg}~\mathrm{s}^{-1}) = 45.91\pm0.38$ 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.