The puzzling case of GRB 990123: prompt emission and broad-band afterglow modeling

• Published in: Astronomy and astrophysics (Berlin) Vol. 438; no. 3; pp. 829 - 840
• Main Authors: Corsi, A., Piro, L., Kuulkers, E., Amati, L., Antonelli, L. A., Costa, E., Feroci, M., Frontera, F., Guidorzi, C., Heise, J., in 't Zand, J., Maiorano, E., Montanari, E., Nicastro, L., Pian, E., Soffitta, P.
• Format: Journal Article
• Language: English
• Published: Les Ulis EDP Sciences 01.08.2005
• Subjects: cosmology: observations; gamma rays: bursts; radiation mechanisms: non-thermal; X-rays: bursts; radiation mechanisms: non-thermal; keV range; X ray observation; X ray burst; Hard x radiation; Light curves; Cosmic gamma bursts; X-ray spectra; Gamma ray burst; Fireball model; Nonthermal radiation; Upper bound; Afterglow; Light emission; Inverse Compton scattering; Standard model; Cosmology; Modelling; cosmology: observations; X ray emission; X-rays: bursts; gamma rays: bursts

We report on BeppoSAX simultaneous X- and γ-ray observations of the bright γ-ray burst (GRB) 990123. We present the broad-band spectrum of the prompt emission, including optical, X- and γ-rays, confirming the suggestion that the emission mechanisms at low and high frequencies must have different phy...