Name of the Speaker(s):Eriko Idesawa
Institution: Makishima-group, Department of Physics, School of Science, University of Tokyo, 7-3-1 Hongou, Bunkyo-ku, Tokyo 113, Japan
Title of the communication: X-Ray Observation of the BL Lac Object OJ287 with ASCA
Preliminary abstract (12 lines max.): We present ASCA observation results of OJ287 in November 1994. Observed X-ray flux was fainter than those from previous observations. The X-ray spectrum is described well with a single power law model, although, convex broken power law model is also acceptable. The slope is flatter than those previously reported, and X-rays exceeds the extrapolation from radio/IR/optical/UV spectrum. This suggests strongly that X-rays include an additional component to radio to UV single synchrotron emission. It is likely that the X-rays from OJ287 contain synchrotron-self-Compton emission. A few hours scale variability was also detected with a soft-lagged behavior known as a characteristic of synchrotron emission.