Rapid Synchrotron Flares from BL Lacertae Detected by ASCA and RXTE
Abstract
We report the variable X-ray emission from BL Lacertae detected in the ASCA ToO observation conducted during the EGRET and RXTE pointings, coincident with the 1997 July outburst. The source showed a historically high state of X-ray, optical, and gamma-ray emission, with its 2-10 keV flux peaking at ~3.3 E-11 erg/cm2/s. This is more than 3 times higher than the value measured by ASCA in 1995. We detected two rapid flares which occured only in the soft X-ray band, while the hard X-ray flux also increased, but decayed with a much longer time scale. Together with the requirement of a very steep and varying power law dominating the soft X-ray band in addition to the hard power law, we suggest that both the high energy end of the synchrotron spectrum and the hard inverse Compton spectrum were visible in this source during the outburst. We discuss the possible origins of the observed variability time scales, and interpret the short time scales of the soft X-ray variability as reflecting the size of the emission region.
Cite
@article{arxiv.astro-ph/0006195,
title = {Rapid Synchrotron Flares from BL Lacertae Detected by ASCA and RXTE},
author = {C. Tanihata and T. Takahashi and J. Kataoka and G. M. Madejski and S. Inoue and H. Kubo and F. Makino and J. R. Mattox and N. Kawai},
journal= {arXiv preprint arXiv:astro-ph/0006195},
year = {2009}
}
Comments
20 pages, 4 figures, accepted for publication in the Astrophysical Journal