XTE observations of PKS 2155-304

Session 31 - Radiogalaxies - High Energy.
Oral session, Monday, January 13
Pier 4,

[31.03] XTE observations of PKS 2155-304

R. M. Sambruna, G. Madejski (NASA/GSFC), C. M. Urry, J. E. Pesce (STScI), L. Maraschi, L. Stella, G. Tagliaferri (Obs. of Brera), A. Celotti, A. Treves (SISSA), R. I. Kollgaard (SDSS), T. Kii (ISAS), A. E. Wherle (IPAC)

We present the results of the timing and spectral analysis of the first XTE observations of the bright BL Lacertae object PKS 2155-304 (z=0.116), which were performed in May 1996 as part of a 2 weeks multifrequency campaign. The XTE observations started May 16, 1996 and lasted a total of 10 days, with evenly spaced 500-sec pointings 8 times per day. A 2-day continuous monitoring was also performed. The preliminary PCA light curve appears to show short-term variability with flux changes of about a factor 2 within a few hours, superimposed on a longer-timescale variability trend.

Program listing for Monday