Gas inflow and outflow in an interacting high-redshift galaxy. The remarkable host environment of GRB 080810 at z = 3.35

DOI: 
10.1051/0004-6361/201731065
Publication date: 
01/11/2017
Main author: 
Wiseman, P.
IAA authors: 
de Ugarte Postigo, A.
Authors: 
Wiseman, P.;Perley, D. A.;Schady, P.;Prochaska, J. X.;de Ugarte Postigo, A.;Krühler, T.;Yates, R. M.;Greiner, J.
Journal: 
Astronomy and Astrophysics
Refereed: 
Yes
Publication type: 
Article
Volume: 
607
Pages: 
A107
Abstract: 

We reveal multiple components of an interacting galaxy system at z ≈ 3.35 through a detailed analysis of the exquisite high-resolution Keck/HIRES spectrum of the afterglow of a gamma-ray burst (GRB). Through Voigt-profile fitting of absorption lines from the Lyman series, we constrain the neutral hydrogen column density to N<SUB>H i</SUB> ≤ 10<SUP>18.35</SUP> cm<SUP>-2</SUP> for the densest of four distinct systems at the host redshift of GRB 080810, which is among the lowest N<SUB>H i</SUB> ever observed in a GRB host, even though the line of sight passes within a projected 5 kpc of the galaxy centres. By detailed analysis of the corresponding metal absorption lines, we derive chemical, ionic, and kinematic properties of the individual absorbing systems, and thus build a picture of the host as a whole. Striking differences between the systems imply that the line of sight passes through several phases of gas: the star-forming regions of the GRB host; enriched material in the form of a galactic outflow; the hot and ionised halo of a second interacting galaxy falling towards the host at a line-of-sight velocity of 700 km s<SUP>-1</SUP>; and a cool metal-poor cloud that may represent one of the best candidates yet for the inflow of metal-poor gas from the intergalactic medium. The reduced spectrum is only available at the CDS via anonymous ftp to <A href='http://cdsarc.u-strasbg.fr'>http://cdsarc.u-strasbg.fr</A> (<A href='http://130.79.128.5'>http://130.79.128.5</A>) or via <A href='http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/607/A107'>http://cdsarc.u-...

Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85035085480&doi=10.1051%2f0004-6361%2f201731065&partnerID=40&md5=3fbf08865c6863438634da12d276817f
ADS Bibcode: 
2017A&A...607A.107W
Keywords: 
galaxies: evolution;galaxies: interactions;gamma-ray burst: individual: 080810