Astrophys. J., 849, 32-32 (2017/November-8)
Unusual black hole binary LMC X-3: a transient high-mass X-ray binary that is almost always on?
TORPIN T.J., BOYD P.T., SMALE A.P. and VALENCIC L.A.
Abstract (from CDS):
We have analyzed a rich, multimission, multiwavelength data set from the black hole X-ray binary (BHXB) LMC X-3, covering a new anomalous low state (ALS), during which the source flux falls to an unprecedentedly low and barely detectable level, and a more normal low state. Simultaneous X-ray and UV/optical monitoring data from Swift are combined with pointed observations from the Rossi X-ray Timing Explorer (RXTE) and X-ray Multi-Mirror Mission (XMM-Newton) and light curves from the Monitor of All-Sky X-ray Image (MAXI) instrument to compare the source characteristics during the ALS with those seen during the normal low state. An XMM-Newton spectrum obtained during the ALS can be modeled using an absorbed power law with Γ=1.41±0.65 and a luminosity of 7.97×1033 erg s–1 (0.6-5 keV). The Swift X-ray and UV light curves indicate an X-ray lag of ∼8 days as LMC X-3 abruptly exits the ALS, suggesting that changes in the mass accretion rate from the donor drive the X-ray lag. The normal low state displays an asymmetric profile in which the exit occurs more quickly than the entry, with minimum X-ray flux a factor of ∼4300 brighter than during the ALS. The UV brightness of LMC X-3 in the ALS is also fainter and less variable than during normal low states. The existence of repeated ALSs in LMC X-3, as well as a comparison with other BHXBs, implies that it is very close to the transient/persistent X-ray source dividing line. We conclude that LMC X-3 is a transient source that is almost always "on."
© 2017. The American Astronomical Society. All rights reserved.
accretion, accretion disks - binaries: close - black hole physics - stars: individual: LMC X-3 - X-rays: binaries - X-rays: binaries
View the reference in ADS
To bookmark this query, right click on this link: simbad:2017ApJ...849...32T and select 'bookmark this link' or equivalent in the popup menu