Infrared identification of 4U1323-619 revisited

Abstract

We re-examine the infrared counterpart of the dipping low-mass x-ray binary 4U1323-619. New X-ray data available from the XMM and Chandra observatories combined with archival IR observations from the ESO 3.6m New Technology Telescope allow us to define a new possible counterpart. We present here its photometric properties and compare them with a simple analytical model of an accretion disc illuminated by the hot central corona known to be present in the binary system.Comment: 4 pages, 1 table, 1 figure, accepted to MNRAS Letter

New orbital ephemerides for the dipping source 4U 1323-619: constraining the distance to the source

“…According to the value of A K S , obtained before, we estimate a distance of 4.2 +0.8 −0.7 kpc with a confidence level of 68%. This distance is fully in agreement with the value of distance suggested by Zolotukhin et al (2010).…”

“…This result allows us to confirm the suggestion of Zolotukhin et al (2010) that the B source in Fig. 1 is the IR counterpart of 4U 1323-619.…”

“…Here we took into account an accuracy of 10% in the mass estimation (see Neece 1984). Our result is compatible with 0.25 M , as suggested by Zolotukhin et al (2010). Since the companion star mass is 0.28 M we expect that it is fully convective and, consequently, it cannot have a magnetic field anchored to it (Nelson & Rappaport 2003).…”

“…The same authors also estimate the X-ray position of the source with an associated error of 3 using data of the X-ray Multi Mirror (XMM-Newton) mission. Zolotukhin et al (2010), analysing the 2MASS catalogue, identify two possible infrared counterparts of 4U 1323-619 that are associated with the X-ray position estimated using XMM-Newton data. From the intersection of the positional error boxes of Chandra and XMM-Newton, they suggest that the probable infrared counterpart is a source with a magnitude of 18.12 ± 0.20 in the K s band.…”

Sample of LMXBs in the Galactic bulge - I. Optical and near-infrared constraints from the Virtual Observatory

“…To continue our previous efforts in identifying X‐ray binaries (Zolotukhin 2009; Zolotukhin, Revnivtsev & Shakura 2010), we undertake a systematic study of an unbiased sample of persistent LMXBs in an optical and near‐infrared (NIR) spectral range. The sample of persistent LMXBs is taken from the deep survey of the Galaxy, performed by the INTEGRAL observatory in an energy range of 17–60 keV (Krivonos et al 2007; Revnivtsev et al 2008), which is free from all complications, caused by the interstellar absorption in the Galactic disc.…”