伽玛暴(Gamma-Ray Burst)笔记。记录有关伽玛暴的新文章,另外也包括看的老文章、自己的想法、以及跟天文相关的一些东西。 Feel free to leave me a message by comments or by email.

星期一, 六月 11, 2007

Wiersema 2007 GRB 040924的观测

主要内容:
给出GRB 040924和宿主星系的观测。z = 0.858 ± 0.001

精彩摘抄:
晚期好平啊,说是超新星成分。

文章信息:
arXiv:0706.1345 [ps, pdf, other] : Title: Spectroscopy and multiband photometry of the afterglow of intermediate duration gamma-ray burst 040924 and its host galaxy
Authors: K. Wiersema, A.J. van der Horst, D.A. Kann, E. Rol, R.L.C. Starling, P.A. Curran, J. Gorosabel, A.J. Levan, J.P.U. Fynbo, A. de Ugarte Postigo, R.A.M.J. Wijers, A.J. Castro-Tirado, S.S. Guziy, A. Hornstrup, J. Hjorth, M. Jelinek, B.L. Jensen, M. Kidger, F. Martin-Luis, N.R. Tanvir, P. Tristram, P.M. Vreeswijk
Comments: A&A submitted. 10 pages, 4 figures

We present optical photometry and spectroscopy of the afterglow and host galaxy of gamma-ray burst 040924. This GRB had a rather short duration of T90 ~2.4s, and a well sampled optical afterglow light curve. We aim to use this dataset to find further evidence that this burst is consistent with a massive star core-collapse progenitor. We combine the afterglow data reported here with data taken from the literature and compare the host properties with survey data. We find that the global behaviour of the optical afterglow is well fit by a broken power-law, with a break at ~0.03 days. We determine the redshift z = 0.858 +/- 0.001 from the detected emission lines in our spectrum. Using the spectrum and photometry we derive global properties of the host, showing it to have similar properties to long GRB hosts. We detect the [Ne III] emission line in the spectrum, and compare the fluxes of this line of a sample of 15 long GRB host galaxies with survey data, showing the long GRB hosts to be comparable to local metal-poor emission line galaxies in their [Ne III] emission. We fit the supernova bump accompanying this burst, and find that it is similar to other long GRB supernova bumps, but fainter. All properties of GRB 040924 are consistent with an origin in the core-collapse of a massive star: the supernova, the spectrum and SED of the host and the afterglow.

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