A&A 431, 667-672 (2005)
X-ray properties of the transient pulsar 3A 0535+262 in quiescenceU. Mukherjee and B. Paul
Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, 400 005 Colaba, Mumbai, India
(Received 15 July 2004 / Accepted 27 October 2004)
We present the timing and spectral properties of the transient Be/X-ray binary pulsar 3A 0535+262 during quiescence using three observations with the narrow field imaging instruments (NFI) of BeppoSAX. Assuming a distance of 2 kpc for this system, the 2-10 keV X-ray luminosities measured from the three observations are in the range of 1.5-4.0 10 33 erg s -1, indicating a very low rate of accretion. We report the detection of pulsations at a very low luminosity of 2 10 33 erg s -1 during one of the three observations, though at this accretion rate the system is expected to be in the centrifugally inhibited regime. The X-ray spectra for the unpulsed observations are best modeled as power law type while a combined model of power law and black-body is required to fit the pulsed spectrum.
Key words: stars: pulsars: individual: 3A 0535+262 -- stars: neutron -- stars: circumstellar matter -- X-rays: general -- X-rays: stars
© ESO 2005