The host of GRB 060206 : kinematics of a distant galaxy
Thöne, C. C., Wiersema, K., Ledoux, C., Starling, R. L. C., Ugarte Postigo, A. de, Levan, A. J., Fynbo, J. P. U., Curran, P. A., Gorosabel, J., Horst, A. J. van der (Alexander J. van der), Llorente, A., Rol, E., Tanvir, Nial R., Vreeswijk, P. M., Wijers, Ralph Antoine Marie Joseph, 1964- and Kewley, L. J.. (2008) The host of GRB 060206 : kinematics of a distant galaxy. Astronomy & Astrophysics, Vol.489 (No.1). pp. 37-48. ISSN 0004-6361
WRAP_Levan_35_Host_GRB_aa8549-07.pdf - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Official URL: http://dx.doi.org/10.1051/0004-6361:20078549
Context. GRB afterglow spectra are sensitive probes of interstellar matter along the line-of-sight in their host galaxies, as well as in intervening galaxies. The rapid fading of GRBs makes it very difficult to obtain spectra of sufficient resolution and S/N to allow for these kinds of studies.
Aims. We investigate the state and properties of the interstellar medium in the host of GRB060206 at z = 4.048 with a detailed study of groundstate and finestructure absorption lines in an early afterglow spectrum. This allows us to derive conclusions on the nature and origin of the absorbing structures and their connection to the host galaxy and/or the GRB.
Methods. We used early (starting 1.6 h after the burst) WHT/ISIS optical spectroscopy of the afterglow of the gamma-ray burst GRB060206 detecting a range of metal absorption lines and their finestructure transitions. Additional information is provided by the afterglow lightcurve. The resolution and wavelength range of the spectra and the bright afterglow have facilitated a detailed study and
fitting of the absorption line systems in order to derive column densities. We also used deep imaging to detect the host galaxy and probe the nature of an intervening system at z = 1.48 seen in absorption in the afterglow spectra.
Results. We detect four discrete velocity systems in the resonant metal absorption lines, best explained by shells within and/or around the host created by starburst winds. The finestructure lines have no less than three components with strengths decreasing from the redmost components. We therefore suggest that the finestructure lines are best explained as being produced by UV pumping from which follows that the redmost component is the one closest to the burst where Nv was detected as well. The host is detected in deep HST imaging with F814WAB = 27.48 ± 0.19 mag and a 3σ upper limit of H = 20.6 mag (Vega) is achieved. A candidate counterpart for the intervening absorption system is detected as well, which is quite exceptional for an absorber in the sightline towards a GRB
afterglow. The intervening system shows no temporal evolution as claimed by Hao et al. (2007, ApJ, 659, 99), which we prove from our WHT spectra taken before and Subaru spectra taken during those observations.
|Item Type:||Journal Article|
|Subjects:||Q Science > QB Astronomy|
|Divisions:||Faculty of Science > Physics|
|Library of Congress Subject Headings (LCSH):||Gamma ray bursts, Galaxies -- Evolution, Galaxies -- Motion in line of sight|
|Journal or Publication Title:||Astronomy & Astrophysics|
|Publisher:||E D P Sciences|
|Official Date:||October 2008|
|Page Range:||pp. 37-48|
|Access rights to Published version:||Open Access|
|Funder:||Fifth Framework Programme (European Commission) (FP5), Danmarks Grundforskningsfond [Danish National Research Foundation], Nederlandse Organisatie voor Wetenschappelijk Onderzoek [Netherlands Organisation for Scientific Research] (NWO), Spain. Ministerio de Ciencia e Innovación (MICINN), Instituto de Astrofísica de Canarias, National Science Foundation (U.S.) (NSF), Particle Physics and Astronomy Research Council (Great Britain) (PPARC), National Research Council Canada (NRCC), Chile. Comisión Nacional de Investigación Científica y Tecnológica (CONICYT), Australian Research Council (ARC), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina) (CONICET), Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, National Astronomical Observatory of Japan (NAOJ)|
|Grant number:||639.043.302 (NWO), HPRN-CT-2002-00294 (FP5), ESP2005-07714-C03-03|
Adelberger, K. L., Steidel, C. C., Shapley, A. E.,& Pettini, M. 2003, ApJ, 584, 45
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