A0535+ 26

Abstract:

MH Finger, Computer Sciences Corporation; RB Wilson, Marshall Space Flight Center, NASA; and KS Hagedon, Universities Space Research Association, report for the Compton Gamma Ray Observatory BATSE team:" Hard x-ray pulses in the energy range 20-120 keV are currently being detected from the transient x-ray pulsar A0535+ 26. The present outburst was first detected on Jan. 28. The pulsed flux remained only marginally detectable until Feb. 1. A steady increase in flux began on Feb. 3.0, when the pulsed flux doubled. The spectrum of the phase-averaged pulsed flux on Feb. 3 is adequately fitted by an optically-thin thermal bremsstrahlung model F (E)=(A/E) exp (-E/kT), with a temperature kT= 27.7+/-1.0 keV, and F (50 keV)=(5.1+/-0.1) x 10E-4 photon cmE-2 sE-1 keVE-1. The pulse shape is very broad, with a sharp dip occupying about 0.2 in phase. This is the largest of a series of four consecutive …

Año de publicación:

1994

Keywords:

Fuente:

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