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تسجيل مستخدم جديدDiscovery of an extremely-luminous dust-obscured galaxy observed with SDSS, WISE, JCMT, and SMA
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We present the discovery of an extremely-luminous dust-obscured galaxy (DOG) at $z_{rm spec}$ = 3.703, WISE J101326.25+611220.1. This DOG is selected as a candidate of extremely-luminous infrared (IR) galaxies based on the photometry from the Sloan Digital Sky Survey and Wide-field Infrared Survey Explorer. In order to derive its accurate IR luminosity, we perform follow-up observations at 450 and 850 $mu$m using the Submillimetre Common User Bolometer Array 2 on the James Clerk Maxwell Telescope, and at 870 and 1300 $mu$m using the Submillimeter Array, which enable us to pin down its IR Spectral Energy Distribution (SED). We perform SED fitting using 14 photometric data (0.4 - 1300 $mu$m) and estimate its IR luminosity, $L_{rm IR}$ (8-1000 $mu$m), to be $2.2^{+1.5}_{-1.0}$ $times 10^{14}$ $L_{odot}$, making it one of the most luminous IR galaxies in the Universe. The energy contribution from an active galactic nucleus (AGN) to the IR luminosity is $94^{+6}_{-20}$%, which indicates it is an AGN-dominated DOG. On the other hand, its stellar mass ($M_*$) and star formation rate (SFR) are $log ,(M_ast/M_{odot})$ = $11.2^{+0.6}_{-0.2}$ and $log ,({rm SFR}/M_{odot},{rm yr}^{-1}$) = $3.1^{+0.2}_{-0.1}$, respectively, which means that this DOG can be considered as a starburst galaxy in $M_*$--SFR plane. This extremely-luminous DOG shows significant AGN and star forming activity that provides us an important laboratory to probe the maximum phase of the co-evolution of galaxies and supermassive black holes.
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st temperatures and overall far-IR SEDs are significantly hotter than expected for star-formation. We present here an analysis of the rest-frame optical through mid-IR SEDs for a large sample of these so-called Hot, Dust-Obscured Galaxies (Hot DOGs). We find that the SEDs of Hot DOGs are generally well modeled by the combination of a luminous, yet obscured AGN that dominates the rest-frame emission at $lambda > 1murm m$ and the bolometric luminosity output, and a less luminous host galaxy that is responsible for the bulk of the rest optical/UV emission. Even though the stellar mass of the host galaxies may be as large as $10^{11}-10^{12}~M_{odot}$, the AGN emission, with luminosities comparable to those of the most luminous QSOs known, require that either Hot DOGs have black hole masses significantly in excess of the local relations, or that they radiate significantly above the Eddington limit. We show that, while rare, the number density of Hot DOGs is comparable to that of equally luminous but unobscured (i.e., Type 1) QSOs. This is inconsistent with the trend of a diminishing fraction of obscured objects with increasing luminosity found for less luminous QSOs, possibly indicating a reversal in this relation at high luminosity, and that Hot DOGs are not the torus-obscured counterparts of the known optically selected, largely unobscured Hyper-Luminous QSOs. Hot DOGs may represent a different type of galaxy and thus a new component of the galaxy evolution paradigm. Finally, we discuss the environments of Hot DOGs and show that these objects are in regions as dense as those of known high-redshift proto-clusters.(Abridged)
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