EDP Sciences
Free access
Volume 504, Number 1, September II 2009
Page(s) 45 - 51
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361/200811135
Published online 09 July 2009
A&A 504, 45-51 (2009)
DOI: 10.1051/0004-6361/200811135

Multi-wavelength observations of the GRB 080319B afterglow and the modeling constraints

S. B. Pandey1, A. J. Castro-Tirado2, M. Jelínek2, A. P. Kamble3, J. Gorosabel2, A. de Ugarte Postigo4, S. Prins5, R. Oreiro5, V. Chantry6, S. Trushkin7, M. Bremer8, J. M. Winters8, A. Pozanenko9, Yu. Krugly10, I. Slyusarev10, G. Kornienko11, A. Erofeeva11, K. Misra12, A. N. Ramprakash12, V. Mohan12, D. Bhattacharya12, A. Volnova13, J. Plá14, M. Ibrahimov15, M. Im16, A. Volvach17, and R. A. M. J. Wijers3

1  Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital, India, 263129, India
    e-mail: shashi@aries.res.in
2  Instituto de Astrofísica de Andalucía (IAA-CSIC), Apartado de Correos, 3.004, 18.080 Granada, Spain
3  Astronomical Institute “Anton Pannekoek”, Kruislaan, 403, 1098SJ, Amsterdam, The Netherlands
4  European Southern Observatory, Casilla 19001, Santiago 19, Chile
5  Institute of Astronomy, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
6  Institut d'Astrophysique et de Geophysique, Université de Liège, Allée du 6 Août 17, Sart Tilman (Bât. B5C), Liège 1, Belgium
7  Special Astrophysical Observatory of RAS, Nizhnij Arkhyz, Karachai-Cherkessia, 369167 Russia
8  Institute de Radioastronomie Millimétrique (IRAM), 300 rue de la Piscine, 38406 Saint Martin d'Hères, France
9  Space Research Institute of RAS, Profsoyuznaya, 84/32, Moscow 117997, Russia
10  Astronomical Institute of Kharkov National University, 35 Sumskaya, Kharkov, 61022, Ukraine
11  Ussuriisk Astrophysical observatory, Far East Branch of RAS, Ussuriisk Region, Gornotaejnoe, 692533, Russia
12  Inter-University Center for Astronomy and Astrophysics (IUCAA), Pune, Ganeshkhind, Post-bag No. 4, India
13  Sternberg Astronomical Institute, Moscow State University, Universitetsky pr., 13, Moscow 119992, Russia
14  Instituto de Astrofísica de Canarias (IAC), Via Láctea s/n, 38205 La Laguna (Tenerife), Spain
15  Ulugh Beg Astronomical Institute, Tashkent 700052, Uzbekistan
16  Dept. of Physics & Astronomy, Seoul National University, 56-1 San, Shillim-dong, Kwanak-gu, Seoul, Korea
17  SRI Crimean Astrophysical Observatory, Nauchny, Crimea, 98409, Ukraine

Received 11 October 2008 / Accepted 2 April 2009

Context. We present observations of the GRB  080319B afterglow at optical, mm, and radio frequencies between a few hours and 67 days after the burst.
Aims. We attempt to understand the nature of this extraordinarily bright explosion based on the observed properties and its comparison with afterglow models.
Methods. Our observations and other published multiwavelength data were used to reconstruct the light curves and spectral energy distributions of the burst afterglow.
Results. Our results indicate that the observed features of the afterglow agrees equally well with the inter stellar matter and the stellar wind density profiles of the circumburst medium. In the case of both density profiles, the maximum synchrotron frequency $\nu_{\rm m}$ is below optical value and the cooling break frequency $\nu_{\rm c}$ is below X-rays, ~104 s after the burst. The derived value of the Lorentz factor at the time of naked-eye brightness is also ~300 for a corresponding blast-wave size of ~1018 cm.
Conclusions. The numerical fit to the multiwavelength afterglow data constraints the values of physical parameters and the emission mechanism of the burst.

Key words: gamma rays: bursts

© ESO 2009