TY - JOUR
T1 - The host-galaxy response to the afterglow of GRB 100901A
AU - Hartoog, Olga E.
AU - Wiersema, Klaas
AU - Vreeswijk, Paul M.
AU - Kaper, Lex
AU - Tanvir, Nial R.
AU - Savaglio, Sandra
AU - Berger, Edo
AU - Chornock, Ryan
AU - Covino, Stefano
AU - D'Elia, Valerio
AU - Flores, Hector
AU - Fynbo, Johan P.U.
AU - Goldoni, Paolo
AU - Gomboc, Andreja
AU - Melandri, Andrea
AU - Pozanenko, Alexei
AU - Schaye, Joop
AU - Postigo, Antonio de Ugarte
AU - Wijers, Ralph A.M.J.
PY - 2013/4/21
Y1 - 2013/4/21
N2 - For gamma-ray burst 100901A, we have obtained Gemini-North and Very Large Telescope optical afterglow spectra at four epochs: 1 h, 1 d, 3 d and 1 week after the burst, thanks to the afterglow remaining unusually bright at late times. Apart from a wealth of metal resonance lines, we also detect lines arising from fine-structure levels of the ground state of Fe II, and from metastable levels of Fe II and Ni II at the host redshift (z = 1.4084). These lines are found to vary significantly in time. The combination of the data and modelling results shows that we detect the fall of the Ni II 4F9/2 metastable level population, which to date has not been observed. Assuming that the population of the excited states is due to the ultraviolet radiation of the afterglow, we estimate an absorber distance of a few hundred pc. This appears to be a typical value when compared to similar studies. We detect two intervening absorbers (z = 1.3147, 1.3179). Despite the wide temporal range of the data, we do not see significant variation in the absorption lines of these two intervening systems.
AB - For gamma-ray burst 100901A, we have obtained Gemini-North and Very Large Telescope optical afterglow spectra at four epochs: 1 h, 1 d, 3 d and 1 week after the burst, thanks to the afterglow remaining unusually bright at late times. Apart from a wealth of metal resonance lines, we also detect lines arising from fine-structure levels of the ground state of Fe II, and from metastable levels of Fe II and Ni II at the host redshift (z = 1.4084). These lines are found to vary significantly in time. The combination of the data and modelling results shows that we detect the fall of the Ni II 4F9/2 metastable level population, which to date has not been observed. Assuming that the population of the excited states is due to the ultraviolet radiation of the afterglow, we estimate an absorber distance of a few hundred pc. This appears to be a typical value when compared to similar studies. We detect two intervening absorbers (z = 1.3147, 1.3179). Despite the wide temporal range of the data, we do not see significant variation in the absorption lines of these two intervening systems.
KW - Abundances-galaxies
KW - Distances and redshifts-galaxies
KW - GRB 100901A-galaxies
KW - Gamma-ray burst
KW - ISM
KW - Individual
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U2 - 10.1093/mnras/stt078
DO - 10.1093/mnras/stt078
M3 - Article
AN - SCOPUS:84876807999
SN - 0035-8711
VL - 430
SP - 2739
EP - 2754
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -