Title:	Chandra and XMM-Newton observations of the low-luminosity X-ray pulsators SAX J1324.4-6200 and SAX J1452.8-5949
Authors:	Kaur, Ramanpreet Wijnands, Rudy Patruno, A. Testa, Vincenzo Israel, Gianluca Degenaar, Nathalie Paul, Biswajit Kumar, Brijesh
Issue Date:	Apr-2009
Publisher:	Blackwell Publishing for the RAS
Citation:	Monthly Notices of the Royal Astronomical Society, 2009, Vol. 394(3), p1597-1604
Abstract:	We present results from our Chandra and XMM–Newton observations of two low-luminosity X-ray pulsators SAX J1324.4−6200 and SAX J1452.8−5949 which have spin periods of 172 and 437 s, respectively. The XMM–Newton spectra for both sources can be fitted well with a simple power-law model of photon index, Γ∼ 1.0 . A blackbody model can equally well fit the spectra with a temperature, kT∼ 2 keV, for both sources. During our XMM–Newton observations, SAX J1324.4−6200 is detected with coherent X-ray pulsations at a period of 172.86 ± 0.02 s while no pulsations with a pulse fraction greater than 18 per cent (at 95 per cent confidence level) in 0.2–12 keV energy band are detected in SAX J1452.8−5949 . The spin period of SAX J1324.4−6200 is found to be increasing on a time-scale of which would suggest that the accretor is a neutron star and not a white dwarf. Using subarcsec spatial resolution of the Chandra telescope, possible counterparts are seen for both sources in the near-infrared images obtained with the son of infrared spectrometer and array camera (SOFI) instrument on the New Technology Telescope. The X-ray and near-infrared properties of SAX J1324.4−6200 suggest it to be a persistent high-mass accreting X-ray pulsar at a distance ≤8 kpc . We identify the near-infrared counterpart of SAX J1452.8−5949 to be a late-type main-sequence star at a distance ≤10 kpc, thus ruling out SAX J1452.8−5949 to be a high-mass X-ray binary. However, with the present X-ray and near-infrared observations, we cannot make any further conclusive conclusion about the nature of SAX J1452.8−5949 .
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/3755
ISSN:	0035-8711 1365-2966 (Online)
Alternative Location:	http://adsabs.harvard.edu/abs/2009MNRAS.tmp..298K http://arxiv.org/abs/0809.1268 http://dx.doi.org/10.1111/j.1365-2966.2009.14438.x
Copyright:	2009 The Royal Astronomical Society
Appears in Collections:	Research Papers (A&A)

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