Frequency Resolved Spectroscopy of XB 1323-619 Using XMM-Newton data: Detection of a Reflection Region in the Disk

Abstract

We present the frequency resolved energy spectra (FRS) of the low-mass X-ray binary dipper XB 1323-619 during persistent emission in four different frequency bands using an archival XMM-Newton observation. FRS method helps to probe the inner zones of an accretion disk. We find that the FRS is well described by a single blackbody component with kT in a range 1.0-1.4 keV responsible for the source variability in the frequency ranges 0.002-0.04 Hz, and 0.07-0.3 Hz. We attribute this component to the accretion disk and possibly emission from an existing boundary layer supported by radiation pressure. The appearance of the blackbody component in the lower frequency ranges and disappearance towards the higher frequencies suggests that it may also be a disk-blackbody emission. We detect a different form of FRS for the higher frequency ranges 0.9-6 Hz and 8-30 Hz which is modeled best with a power-law and a Gaussian emission line at 6.4${}_{-0.3}^{+0.2}$ keV with an equivalent width of 1.6${}_{-1.2}^{+0.4}$ keV and 1.3${}_{-0.9}^{+0.7}$ keV for the two frequency ranges, respectively. This iron fluorescence line detected in the higher frequency ranges of spectra shows the existence of reflection in this system within the inner disk regions. In addition, we find that the 0.9-6 Hz frequency band shows two QPO peaks at 1.4${}_{-0.2}^{+1.0}$ Hz and 2.8${}_{-0.2}^{+0.2}$ Hz at about 2.8-3.1 $\sigma$ confidence level. These are consistent with the previously detected $\sim$ 1 Hz QPO from this source (Jonker et al. 1999). We believe they relate to the reflection phenomenon. The emission from the reflection region, being a variable spectral component in this system, originates from the inner regions of the disk with a maximum size of 4.7$\times 10^9$ cm and a minimum size of 1.6$\times 10^8$ cm calculated using light travel time considerations and our frequency resolved spectra.

9 journal pages, 7 figures, one table; accepted to MNRAS as it stands

References in corpus (12)

• Relativistic X-ray Lines from the Inner Accretion Disks Around Black Holes
• Relativistic iron emission lines in neutron star low-mass X-ray binaries as probes of neutron star radii
• Broad relativistic iron emission line observed in SAX J1808.4-3658
• XMM-Newton detects a relativistically broadened iron line in the spectrum of the ms X-ray pulsar SAX J1808.4-3658
• A relativistically smeared spectrum in the neutron star X-ray Binary 4U 1705-44: Looking at the inner accretion disc with X-ray spectroscopy
• Variations in the dip properties of the low-mass X-ray binary XB 1254-69 observed with XMM-Newton and INTEGRAL
• Suzaku broadband spectroscopy of Swift J1753.5-0127 in the Low-Hard State
• Relativistically broadened iron line in the SUZAKU observation of the neutron star X-ray binary 4U 1705-44
• INTEGRAL and BeppoSAX observations of the transient atoll source 4U 1608-522: from quiescent to hard spectral state
• A study of the low-mass X-ray binary dip sources XB 1916-053, XB 1323-619, X 1624-490 and 4U 1746-371 observed with INTEGRAL
• Neutral absorber dips in the periodic burster LMXB XB 1323-619 from Suzaku
• Fourier resolved spectroscopy of 4U 1728-34: New Insights into Spectral and Temporal Properties of Low-Mass X-ray Binaries

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