P. C. Agrawal

X-Ray Telescope For Sounding Rocket-Borne Observations

The X-ray astronomy group at Caltech has developed an X-ray telescope for sounding rocket-borne observations above the Earths atmosphere. The telescope consists of a pair of nested aluminum mirrors, 40.64 cm and 31.65 cm in diameter with a total geometrical collecting area of 200 cm2. The mirror surfaces have been machined at the Y-12 plant of the Oak Ridge National Laboratory using an air bearing spindle lathe and a diamond tool. Design and performance characteristics will be presented. The design of the next generation telescope of 91 cm diameter will be presented.

The X-ray spectrum of the BL Lacertae object PKS 0548-322

X-ray observations of H0548-322 = PKS 0548-322 at energies from 0.15 keV to 24 keV with the HEAO A-2 experiment are reported. The spectrum shows a distinct break in slope near 2 keV, with the indices of power-law energy spectra of 2.2 below and 0.3 above this break. A synchrotron self-Compton model is consistent with radio, optical, and all X-ray data, although a modified synchrotron self-Compton model with added thermal origin for the low-energy X-ray spectrum is also plausible.