Relativistically broadened iron line in the SUZAKU observation of the neutron star X-ray binary 4U 1705-44

Abstract

The X-ray spectra of accreting compact objects often exhibit discrete emission features associated with fluorescent emission in the accretion disk, the strongest of which is the Fe Kalpha fluorescence line at 6.4--6.97keV. These reflection features are amongst the best tools in the study of the inner region of accretion flow around a compact object. Here we report on three Suzaku observations of the neutron star X-ray binary 4U1705-44 where a broad, skewed Fe Kalpha emission line is clearly visible above the continuum. By using a relativistically-blurred reflection model we find that in 4U1705-44 the inner disk radius extends down to rin=10.5^{+1.0}_{-1.7} GM/c^2 and is at an angle of 29.8^{+1.1}_{-1.0} degrees to the line of sight. Furthermore, we find that the level of ionisation in the surface layers of the accretion disk changes by two orders of magnitude between the three observations, however the inner radius obtained from the line profile remains stable.

Accepted for publication in MNRAS, 5 pages, 3 figures

References in corpus (10)

• Constraining Black Hole Spin Via X-ray Spectroscopy
• Relativistic X-ray Lines from the Inner Accretion Disks Around Black Holes
• Evaluating Spectral Models and the X-ray States of Neutron-Star X-ray Transients
• Relativistic iron emission lines in neutron star low-mass X-ray binaries as probes of neutron star radii
• A systematic look at the Very High and Low/Hard state of GX 339-4: Constraining the black hole spin with a new reflection model
• Broad relativistic iron emission line observed in SAX J1808.4-3658
• X-ray reflection in accreting stellar-mass black hole systems
• XMM-Newton detects a relativistically broadened iron line in the spectrum of the ms X-ray pulsar SAX J1808.4-3658
• Evidence of a Broad Relativistic Iron Line from the Neutron Star Low-Mass X-ray Binary Serpens X-1
• BeppoSAX observation of 4U 1705-44: detection of hard X-ray emission in the soft state

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• A self-consistent approach to the hard and soft states of 4U 1705-44
• Suzaku broad-band spectrum of 4U 1705-44: Probing the Reflection component in the hard state
• X-ray reflection in a sample of X-ray bright Ultraluminous X-ray sources
• NuSTAR and XMM-Newton Observations of the Neutron Star X-ray Binary 1RXS J180408.9-34205
• A relativistically broadened O VIII Lyalpha line in the ultra-compact X-ray binary 4U 0614+091
• Study of the reflection spectrum of the LMXB 4U 1702-429
• On the disc reflection spectroscopy of NS LMXB Serpens~X-1: analysis of a recent NuSTAR observation
• Relativistic Disk Reflection in the Neutron Star X-ray Binary XTE J1709-267 with NuSTAR
• High-frequency variability in neutron-star low-mass X-ray binaries
• Are the kHz QPO lags in neutron star 4U 1608-52 due to reverberation?
• Broadband spectral analysis of MXB 1659-298 in its soft and hard state
• The broadband spectral analysis of 4U 1702-429 using XMM-Newton and BeppoSAX data
• Study of the reflection spectrum of the bright atoll source GX 3+1 with NuSTAR
• Broad iron emission line and kilohertz quasi-periodic oscillations in the neutron star system 4U 1636-53
• Evidence of disc reflection in the X-ray spectrum of the neutron star low mass X-ray binary 4U 1636-536
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• Frequency Resolved Spectroscopy of XB 1323-619 Using XMM-Newton data: Detection of a Reflection Region in the Disk
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