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Author Kaur, R. ♦ Wijnands, R. ♦ Patruno, A. ♦ Testa, V. ♦ Israel, G. ♦ Degenaar, N. ♦ Paul, B. ♦ Kumar, B.
Source Aryabhatta Research Institute of Observational Sciences (ARIES)
Content type Text
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics
Subject Keyword Binaries ♦ Close – stars ♦ Neutron – pulsars ♦ SAX J1324.4−6200 ♦ SAXJ1452.8−5949 – X-rays
Abstract We present results from our Chandra and XMM–Newton observations of two low-luminosityX-ray pulsators SAX J1324.4−6200 and SAX J1452.8−5949 which have spin periods of 172and 437 s, respectively. The XMM–Newton spectra for both sources can be fitted well with asimple power-law model of photon index, ∼ 1.0. A blackbody model can equally well fit thespectra with a temperature, kT ∼ 2 keV, for both sources. During our XMM–Newton observa-tions, 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 confi-dence level) in 0.2–12 keV energy band are detected in SAX J1452.8−5949. The spin period ofSAX J1324.4−6200 is found to be increasing on a time-scale of P = (6.34±0.08)×10−9 s s−1 ̇which would suggest that the accretor is a neutron star and not a white dwarf. Using subarcsecspatial resolution of the Chandra telescope, possible counterparts are seen for both sourcesin 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 propertiesof SAX J1324.4−6200 suggest it to be a persistent high-mass accreting X-ray pulsar at adistance ≤8 kpc. We identify the near-infrared counterpart of SAX J1452.8−5949 to be alate-type main-sequence star at a distance ≤10 kpc, thus ruling out SAX J1452.8−5949 to bea 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.
Part of series Mon. Not. R. Astron. Soc.
Educational Use Research
Education Level UG and PG
Learning Resource Type Article