Broad–band spectral evolution of GRB afterglows

N. Masetti; E. Pian; E. Palazzi; L. Amati; T. J. Galama; L. Nicastro; P. M. Vreeswijk; F. Frontera; J. van Paradijs

doi:10.1051/aas:1999305

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Volume 138 / No 3 (September 1999)

Astron. Astrophys. Suppl. Ser., 138 3 (1999) 453-454

Abstract

Free Access

Issue		Astron. Astrophys. Suppl. Ser. Volume 138, Number 3, September 1999 Gamma-Ray Bursts in the Afterglow Era Contents Rome, November 3-6, 1998


Page(s)		453 - 454
DOI		https://doi.org/10.1051/aas:1999305
Published online		15 September 1999

Astron. Astrophys. Suppl. Ser. 138, 453-454 (1999)

Broad–band spectral evolution of GRB afterglows

N. Masetti¹, E. Pian¹, E. Palazzi¹, L. Amati¹, T. J. Galama², L. Nicastro³, P. M. Vreeswijk², F. Frontera¹ and J. van Paradijs²

¹ Istituto Te.S.R.E., CNR, via Gobetti 101, I-40129 Bologna, Italy
² Astronomical Institute "Anton Pannekoek", Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
³ I.F.C.A.I., CNR, via Ugo La Malfa 153, I-90146 Palermo, Italy

Received: 29 December 1998
Accepted: 21 April 1999

Abstract

Quasi-simultaneous Spectral Energy Distributions (SEDs) at different epochs of four among the most intensively observed Gamma-Ray Burst (GRB) afterglows have been constructed in order to investigate and compare the temporal evolution of their multiwavelength emission. The data suggest that generally the peak frequency moves toward lower frequencies with time. SED local maxima in the optical/IR range are present in some cases, possibly due to dust absorption within the host galaxy.

Key words: methods: data analysis / gamma-rays: bursts