J1406+0102: A Dust-obscured Galaxy Hiding a 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 BH ≳ 10 9 M ⊙ at z ≳ 7. Motivated by theoretical predictions that the super-Eddington phase efficiently produces outflows and bright jets 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 A. Noboriguchi et al. with the Very Large Array/Far-Infrared and Submillimetre Telescope 1.4 GHz radio survey data and the Sloan Digital Sky Survey 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 black hole (BH) mass estimations of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mspace width="1em"/> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">BH</mml:mi> </mml:mrow> </mml:msub> <mml:mo>/</mml:mo> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> <mml:mo stretchy="false">)</mml:mo> <mml:mo>=</mml:mo> <mml:mn>7.30</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.25</mml:mn> </mml:math> . Combined with an active galactic nucleus (AGN) luminosity of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mi>L</mml:mi> <mml:mrow> <mml:mi>bol</mml:mi> <mml:mo>,</mml:mo> <mml:mo stretchy="false">[</mml:mo> <mml:mi mathvariant="normal">O</mml:mi> <mml:mspace width="0.25em"/> <mml:mi>III</mml:mi> <mml:mo stretchy="false">]</mml:mo> </mml:mrow> </mml:msub> <mml:mo>/</mml:mo> <mml:mi>erg</mml:mi> <mml:mspace width="1em"/> <mml:msup> <mml:mi mathvariant="normal">s</mml:mi> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mo stretchy="false">)</mml:mo> <mml:mo>=</mml:mo> <mml:mn>45.91</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.38</mml:mn> </mml:math> estimated from the intrinsic [O iii ] luminosity, this implies a super-Eddington accretion rate of λ Edd ≃ 3. We show that (1) J1406+0102 shows strong AGN feedback, with the [O i ii ] outflow velocity exceeding the escape velocity of the host galaxy halo and a kinetic efficiency of ≈8%, sufficient to quench the host galaxy; (2) its expected growth trajectory places it on an overmassive BH track; and (3) if representative of radio-loud DOGs, such sources can contribute significantly to the high-energy (≳100 TeV) cosmic neutrino background.