Please use this identifier to cite or link to this item:
Title: The host of GRB 030323 at z = 3.372: A very high column density DLA system with a low metallicity
Authors: Vreeswijk, P. M.
Ellison, S. L.
Ledoux, C.
Ellison, S. L.
Wijers, R. A. M. J.
Rol, E.
Kaper, L.
Van Den Heuvel EPJ
Fynbo, J. P. U.
Fynbo, J. P. U.
Hjorth, J.
Jensen, B. L.
Pedersen, H.
Møller, P.
Henden, A.
Masi, G.
Tanvir, N.
Levan, A.
Castro Cerón JM
Gorosabel, J.
Fruchter, A. S.
Burud, I.
Rhoads, J.
Gorosabel, J.
Castro-Tirado, A. J.
Kouveliotou, C.
Masetti, N.
Palazzi, E.
Pian, E.
Pian, E.
Gilmore, A.
Kilmartin, P.
Buckle, J. V.
Seigar, M. S.
Hartmann, D. H.
Lindsay, K.
First Published: Jun-2004
Publisher: EDP Sciences for European Southern Observatory (ESO)
Citation: Astronomy & Astrophysics, 2004, 419 (3), pp. 927-940
Abstract: We present photometry and spectroscopy of the afterglow of GRB 030323. VLT spectra of the afterglow show damped Ly $\alpha$ (DLA) absorption and low- and high-ionization lines at a redshift $z=3.3718\pm0.0005$. The inferred neutral hydrogen column density, $\log N({\ion{H}{i}})=21.90\pm0.07$, is larger than any (GRB- or QSO-) DLA $\ion{H}{i}$ column density inferred directly from Ly $\alpha$ in absorption. From the afterglow photometry, we derive a conservative upper limit to the host-galaxy extinction: $A_{\rm V}<0.5$ mag. The iron abundance is $\rm [Fe/H]=-1.47\pm0.11$, while the metallicity of the gas as measured from sulphur is $\rm [S/H]=-1.26\pm0.20$. We derive an upper limit on the H 2 molecular fraction of $2N({\rm H_2)}/(2N{\rm (H_2)}+N({\ion{H}{i}}))\la10^{-6}$. In the Ly $\alpha$ trough, a Ly $\alpha$ emission line is detected, which corresponds to a star-formation rate (not corrected for dust extinction) of roughly 1 M $_{\odot}$ yr -1. All these results are consistent with the host galaxy of GRB 030323 consisting of a low metallicity gas with a low dust content. We detect fine-structure lines of silicon, $\ion{Si}{ii}$*, which have never been clearly detected in QSO-DLAs; this suggests that these lines are produced in the vicinity of the GRB explosion site. Under the assumption that these fine-structure levels are populated by particle collisions, we estimate the $\ion{H}{i}$ volume density to be $n_{\ion{H}{i}}=10^2{-}10^4$ cm -3. HST/ACS imaging 4 months after the burst shows an extended ${\it AB}(F606W)=28.0\pm0.3$ mag object at a distance of 014 (1 kpc) from the early afterglow location, which presumably is the host galaxy of GRB 030323.
DOI Link: 10.1051/0004-6361:20040086
ISSN: 0004-6361
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2004 ESO. Reproduced with permission from Astronomy & Astrophysics, © ESO.
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

Files in This Item:
File Description SizeFormat 
aah4670.pdfPublished (publisher PDF)757.76 kBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.