GRB 030227: The first multiwavelength afterglow of an INTEGRAL GRB
Pian, E.;
Palazzi, E.;
Greiner, J.;
Tiengo, A.;
Mereghetti, S.;
Kouveliotou, C.;
Kaper, L.;
Tanvir, N.;
Vreeswijk, P. M.;
Wijers, R. A. M. J.;
Rol, E.;
Masetti, N.;
Pedersen, H.;
Klose, S.;
Pandey, S. B.;
Fynbo, J. P. U.;
Mannucci, F.;
Lund, N.;
Gorosabel, J.;
Sagar, R.;
Castro-Tirado, A. J.;
Hjorth, J.;
de Ugarte Postigo, A.;
Castro Cerón, J. M.;
Jensen, B. L.;
Brandt, S.;
Buckle, J.;
Feltzing, S.;
Fruchter, A.;
Reglero, V.;
Andersen, M. I.;
Rhoads, J.;
Trushkin, S.;
Mohan, V.;
Guziy, S.;
van den Heuvel, E.;
Pérez-Ramírez, M. D.;
Martínez Núñez, S.;
Vílchez, J.;
Reverte, D.;
Lundstrom, I.;
Riess, C.
Spain, United States, United Kingdom, Italy, India, Sweden, Denmark, Germany, Russia, Netherlands, Chile
Abstract
We present multiwavelength observations of a gamma-ray burst detected by INTEGRAL (GRB 030227) between 5.3 hours and ~ 1.7 days after the event. Here we report the discovery of a dim optical afterglow (OA) that would not have been detected by many previous searches due to its faintess (R ~ 23). This OA was seen to decline following a power law decay with index alpha R = -0.95 +/- 0.16. The spectral index beta_ opt/NIR yielded -1.25 +/- 0.14. These values may be explained by a relativistic expansion of a fireball (with p = 2.0) in the cooling regime. We also find evidence for inverse Compton scattering in X-rays.
Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland, and with the participation of Russia and the USA. Also partially based on observations collected by the Gamma-Ray Burst Collaboration at ESO (GRACE) at the European Southern Observatory, Chile (ESO Large Programme 165.H-0464).
2003
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Astronomy and Astrophysics
INTEGRAL
23
