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Title: Extended Lyα emission from a damped Lyα absorber at z = 3.115

We searched for star formation activity associated with high-z damped Lyα systems (DLAs) with the Subaru telescope. We used a set of narrow-band (NB) filters whose central wavelengths correspond to the redshifted Lyα emission lines of targeted DLA absorbers at 3 < z < 4.5. We detected one apparent NB-excess object located 3.80 arcsec (∼28 h{sub 70}{sup −1} kpc) away from the quasar SDSS J031036.84+005521.7. Follow-up spectroscopy revealed an asymmetric Lyα emission at z {sub em} = 3.115 ± 0.003, which perfectly matches the sub-DLA trough at z {sub abs} = 3.1150 with logN(H I)/cm{sup –2} = 20.05. The Lyα luminosity is estimated to be L {sub Lyα} = 1.07 × 10{sup 42} erg s{sup –1}, which corresponds to a star formation rate of 0.97 M {sub ☉} yr{sup –1}. Interestingly, the detected Lyα emission is spatially extended with a sharp peak. The large extent of the Lyα emission is remarkably one-sided toward the quasar line-of-sight and is redshifted. The observed spatially asymmetric surface brightness profile can be qualitatively explained by a model of a DLA host galaxy, assuming a galactic outflow and a clumpy distribution of H I clouds in the circumgalactic medium. This large Lyα extension, which ismore » similar to those found in Rauch et al., could be the result of complicated anisotropic radiative transfer through the surrounding neutral gas embedded in the DLA.« less
Authors:
 [1] ;  [2] ; ;  [3] ;  [4] ; ; ;  [5]
  1. Optical and Infrared Astronomy Division, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan)
  2. School of General Education, Shinshu University, 3-1-1, Asahi, Matsumoto, Nagano 390-8621 (Japan)
  3. Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 96720 (United States)
  4. Tokyo University of Science, Tomino 102-1, Oshamambe, Hokkaido, 049-3514 (Japan)
  5. Department of Astronomy, School of Science, Graduate University for Advanced Studies, Mitaka, Tokyo 181-8588 (Japan)
Publication Date:
OSTI Identifier:
22348270
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 780; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; ANISOTROPY; ASYMMETRY; BRIGHTNESS; COSMOLOGY; DISTRIBUTION; EMISSION; FILTERS; GALAXIES; LUMINOSITY; QUASARS; RADIANT HEAT TRANSFER; RED SHIFT; SPECTROSCOPY; STARS; SURFACES; TELESCOPES