EDP Sciences
Free access
Issue
A&A
Volume 431, Number 2, February IV 2005
Page(s) 667 - 672
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20041665


A&A 431, 667-672 (2005)
DOI: 10.1051/0004-6361:20041665

X-ray properties of the transient pulsar 3A 0535+262 in quiescence

U. Mukherjee and B. Paul

Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, 400 005 Colaba, Mumbai, India
    e-mail: [uddipan;bpaul]@tifr.res.in

(Received 15 July 2004 / Accepted 27 October 2004)

Abstract
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 $\times$ 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 $\times$ 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

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