The afterglow and the host galaxy of GRB 011211

• DOI: 10.1051/0004-6361:20031044
• Publication Date: 2003-09-09T13:56:50Z
• Authors: P. Jakobsson; J. Hjorth; J. P. U. Fynbo; J. Gorosabel; K. Pedersen; I. Burud; A. Levan; C. Kouveliotou; N. Tanvir; A. Fruchter; J. Rhoads; T. Grav; M. W. Hansen; R. Michelsen; M. I. Andersen; B. L. Jensen; H. Pedersen; B. Thomsen; M. Weidinger; S. G. Bhargavi; R. Cowsik; S. B. Pandey
• Keywords: Spectral index; Extinction (optical mineralogy); Spectral energy distribution

We present optical, near-infrared, and X-ray observations of the optical afterglow (OA) rich, long-duration gamma-ray burst GRB 011211. Hubble Space Telescope (HST) data obtained 14, 26, 32, 59 days after burst, show host galaxy to have a morphology that is fairly typical blue galaxies at high redshift. measure its magnitude be . detect break in OA R-band light curve which naturally accounted for by collimated outflow geometry. By fitting broken power-law we find best fit with pre-break slope , post-break The UV-optical spectral energy distribution (SED) around 14 hours index reddened an SMC-like extinction law modest mag. comparison, from XMM-Newton same time, decay Interpolating between implies cooling frequency located close ~1016 Hz observer frame time observations. argue, using various temporal indices above, most likely model jet expanding into external environment has constant mean density rather than wind-fed structure. estimate electron this