|
|||||
|
|
The 0.1–100 keV spectrum and variability of Mrk 421 in a high state |
|
| Authors: | A Malizia M Capalbi F Fiore P Giommi G Gandolfi A Tesseri L A Antonelli R C Butler G Celidonio A Coletta L Di Ciolo J M Muller L Piro S Rebecchi D Ricci R Ricci M Smith V Torroni |
| Institution: | BeppoSAX Science Data Center, Via Corcolle 19, I-00131 Roma, Italy; Department of Physics and Astronomy, Southampton University, Southampton SO17 1BJ;Telespazio, Via Corcolle 19, I-00131 Roma, Italy; Osservatorio Astronomico di Roma, Via dell'Osservatorio, I-00044 Monteporzio Catone, Italy; ASI, Area Ricerca Scientifica, Roma, Italy; BeppoSAX SOC, Via Corcolle 19, I-00131 Roma, Italy; SRON, Sorbonnelaan 2, 3584 CA Ultrecht, the Netherlands; Istituto di Astrofisica Spaziale, CNR, Via Fosso Del Cavalire, I-00133, Roma, Italy |
| Abstract: | The results of a BeppoSAX target of opportunity (TOO) observation of the BL Lac object Mrk 421 during a high-intensity state are reported and compared with monitoring X-ray data collected with the BeppoSAX Wide Field Cameras (WFC) and the RXTE All Sky Monitor (ASM). The 0.1–100 keV spectrum of Mrk 421 shows continuous convex curvature that can be interpreted as the high-energy end of the synchrotron emission. The source shows significant short-term temporal and spectral variability, which can be interpreted in terms of synchrotron cooling. The comparison of our results with those of previous observations when the source was a factor 3–5 fainter shows evidence for strong spectral variability, with the maximum of the synchrotron power shifting to higher energy during high states. This behaviour suggests an increase in the number of energetic electrons during high states. |
| Keywords: | galaxies: active BL Lacertae objects: individual: Mrk 421 X-rays: galaxies |