Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-10-06
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
16 pages, 2 tables, 6 figures, accepted for publication in the Astrophysical Journal
Scientific paper
We present results from Submillimeter Array (SMA) 860-micron sub-arcsec astrometry and multiwavelength observations of the brightest millimeter (S_1.1mm = 8.4 mJy) source, SSA22-AzTEC1, found near the core of the SSA22 protocluster that is traced by Ly\alpha emitting galaxies at z = 3.09. We identify a 860-micron counterpart with a flux density of S_860um = 12.2 +/- 2.3 mJy and absolute positional accuracy that is better than 0.3". At the SMA position, we find radio to mid-infrared counterparts, whilst no object is found in Subaru optical and near-infrared deep images at wavelengths \le 1 micron (J > 25.4 in AB, 2\sigma). The photometric redshift estimate, using flux densities at \ge 24 microns, indicates z_phot = 3.19^{+0.26}_{-0.35}, consistent with the protocluster redshift. We then model the near-to-mid-infrared spectral energy distribution (SED) of SSA22-AzTEC1, and find that the SED modeling requires a large extinction (A_V \approx 3.4 mag) of starlight from a stellar component with M_star ~ 10^{10.9} M_sun, assuming z = 3.1. Additionally, we find a significant X-ray counterpart with a very hard spectrum (Gamma_eff = -0.34 ^{+0.57}_{-0.61}), strongly suggesting that SSA22-AzTEC1 harbors a luminous AGN (L_X ~ 3*10^{44} ergs s^{-1}) behind a large hydrogen column (N_H ~ 10^{24} cm^{-2}). The AGN, however, is responsible for only ~10% of the bolometric luminosity of the host galaxy, and therefore the star-formation activity likely dominates the submillimeter emission. It is possible that SSA22-AzTEC1 is the first example of a protoquasar growing at the bottom of the gravitational potential underlying the SSA22 protocluster.
Alexander Dave M.
Chung Aeree
Ezawa Hajime
Hatsukade Bunyo
Hayashino Tomoki
No associations
LandOfFree
Submillimeter Array Identification of the Millimeter-Selected Galaxy SSA22-AzTEC1: A Protoquasar in a Protocluster? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Submillimeter Array Identification of the Millimeter-Selected Galaxy SSA22-AzTEC1: A Protoquasar in a Protocluster?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Submillimeter Array Identification of the Millimeter-Selected Galaxy SSA22-AzTEC1: A Protoquasar in a Protocluster? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-508407