Chandra and XMM-Newton observations of the low-luminosity X-ray pulsators SAX J1324.4-6200 and SAX J1452.8-5949

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 s and 437 s respectively. The XMM-Newton spectra for both sources can be fitted well with a simple power-law model of photon index ~ 1.0. A black-body model can equally well fit the spectra with a temperature of ~ 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 $172.86\pm 0.02$ s while no pulsations with a pulse fraction greater than 15% (at 98% confidence level) 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 $\dot{P}$ = $(6.34\pm 0.08)\times 10^{-9}$ s s${}^{-1}$ which would suggest that the accretor is a neutron star and not a white dwarf. Using sub-arcsec spatial resolution of the Chandra telescope, possible counterparts are seen for both sources in the near-infrared images obtained with the SOFI instrument on the New Technology Telescope. The X-ray and near-infrared properties of SAX J1324.4-6200 suggest it to be either a persistent high mass accreting X-ray pulsar or a symbiotic X-ray binary pulsar at a distance $\le$ 9 kpc. We identify the infrared counterpart of SAX J1452.8--5949 to be a late-type main sequence star at a distance $\le$ 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.

arXiv comment9 pages, 6 figures, 5 tables (Submitted to MNRAS)

References in corpus (14)

• Correcting for the Effects of Interstellar Extinction
• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• Observations of Accreting Pulsars
• A New Class of High-Mass X-ray Binaries: Implications for Core Collapse and Neutron-Star Recoil
• Discovery of two new persistent Be/X-ray pulsar systems
• The Spectra and Variability of X-ray Sources in a Deep Chandra Observation of the Galactic Center
• A Comparison of the Variability of the Symbiotic X-ray Binaries GX 1+4, 4U 1954+31, and 4U 1700+24 from Swift/BAT and RXTE/ASM Observations
• INTEGRAL observation of the accreting pulsar GX 1+4
• A Chandra observation of the old open cluster M67
• XMM-Newton observation of the persistent Be/neutron-star system X Persei at a high-luminosity level
• XMM-Newton EPIC observations of Her X-1
• The Steady Spin Down Rate of 4U 1907+09
• Detection of hard X-ray pulsations and a strong iron K_beta emission line during an extended low state of GX 1+4
• On the nature of the X-ray pulsar SAX J1324-6200

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