Investigating a unique partial eclipse in the High Mass X-ray Binary IGR J16393-4643 with Swift-XRT

Abstract

The orbital profile of the High Mass X-ray binary IGR J16393-4643 shows a dip in its X-ray intensity, which was previously interpreted as an eclipse. Unlike most eclipsing HMXBs, where the X-ray eclipses are about two orders of magnitude fainter compared to the out of eclipse emission, this particular eclipse like feature is narrow and partial, casting doubt if it is indeed an eclipse. To further investigate the nature of this low intensity orbital phase, we use a large number of observations with Swift-XRT, covering the entire orbital phase. The soft X-ray observations also show this low intensity phase, which is about 30% of the intensity during rest of the orbit. We also carried out orbital phase resolved spectroscopy to compare the change in the spectral parameters inside and outside of this low intensity state. The results indicate that this low intensity state might not be an eclipse, as previously thought but absorption in the stellar corona. We have also provided the inclination angle of the binary for grazing eclipse caused by the stellar corona.

References in corpus (17)

• The Swift X-ray Telescope
• The Swift Ultra-Violet/Optical Telescope
• The Burst Alert Telescope (BAT) on the Swift MIDEX Mission
• Faint X-ray sources resolved in the ASCA Galactic plane survey and their contribution to the Galactic ridge X-ray emission
• The ephemeris, orbital decay, and masses of 10 eclipsing HMXBs
• A Systematic Search for Periodicities in RXTE/ASM Data
• An XMM-Newton view of FeKα in HMXBs
• Superorbital Periodic Modulation in Wind-Accretion High-Mass X-ray Binaries from Swift BAT Observations
• X-ray Spectroscopy of the High Mass X-ray Binary Pulsar Centaurus X-3 over its Binary Orbit
• IGR J16393-4643: a new heavily-obscured X-ray pulsar
• Joint H-alpha and X-ray Observations of Massive X-ray Binaries. I. The B-Supergiant System LS I +65 010 = 2S 0114+650
• X-ray reprocessing: Through the eclipse spectra of high mass X-ray binaries with XMM-Newton
• Orbital phase resolved spectroscopy of GX 301-2 with MAXI
• Chandra observations of five INTEGRAL sources: new X-ray positions for IGR J16393-4643 and IGR J17091-3624
• NuSTAR discovery of a cyclotron line in the accreting X-ray pulsar IGR J16393-4643
• A Suzaku view of IGR J16393-4643
• Is 4U 0114+65 an eclipsing HMXB?

Cited by in corpus (3)

• First eccentric inspiral-merger-ringdown analysis of neutron star-black hole mergers
• XMM-Newton and Swift observations of supergiant high mass X-ray binaries
• Superorbital Modulation in the High-Mass X-ray Binary 4U 1538-52, and Possible Modulation in IGR J16393-4643