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Full-Text Articles in Physical Sciences and Mathematics
Broad Iron Lines In Neutrons Stars: Dynamical Broadening Or Wind Scattering?, E. M. Cackett, Jon M. Miller
Broad Iron Lines In Neutrons Stars: Dynamical Broadening Or Wind Scattering?, E. M. Cackett, Jon M. Miller
Physics and Astronomy Faculty Research Publications
Broad iron emission lines are observed in many accreting systems from black holes in active galactic nuclei and X-ray binaries to neutron star low-mass X-ray binaries. The origin of the line broadening is often interpreted as due to dynamical broadening and relativistic effects. However, alternative interpretations have been proposed, included broadening due to Compton scattering in a wind or accretion disk atmosphere. Here we explore the observational signatures expected from broadening in a wind, in particular that the iron line width should increase with an increase in the column density of the absorber (due to an increase in the number …
A Change In The Quiescent X-Ray Spectrum Of The Neutron Star Low-Mass X-Ray Binary Mxb 1659-29, E. M. Cackett, E. F. Brown, A. Cumming, N. Degenaar, J. K. Fridriksson, J. Homan, J. M. Miller, R. Wijnands
A Change In The Quiescent X-Ray Spectrum Of The Neutron Star Low-Mass X-Ray Binary Mxb 1659-29, E. M. Cackett, E. F. Brown, A. Cumming, N. Degenaar, J. K. Fridriksson, J. Homan, J. M. Miller, R. Wijnands
Physics and Astronomy Faculty Research Publications
The quasi-persistent neutron star low-mass X-ray binary MXB 1659-29 went into quiescence in 2001, and we have followed its quiescent X-ray evolution since. Observations over the first 4 yr showed a rapid drop in flux and temperature of the neutron star atmosphere, interpreted as cooling of the neutron star crust which had been heated during the 2.5 yr outburst. However, observations taken approximately 1400 and 2400 days into quiescence were consistent with each other, suggesting the crust had reached thermal equilibrium with the core. Here we present a new Chandra observation of MXB 1659-29 taken 11 yr into quiescence and …
Continued Neutron Star Crust Cooling Of The 11 Hz X-Ray Pulsar In Terzan 5: A Challenge To Heating And Cooling Models?, N. Degenaar, R. Wijnands, E. F. Brown, D. Altamirano, E. M. Cackett, J. Fridriksson, J. Homan, C. O. Heinke, J. M. Miller, D. Pooley, G. R. Sivakoff
Continued Neutron Star Crust Cooling Of The 11 Hz X-Ray Pulsar In Terzan 5: A Challenge To Heating And Cooling Models?, N. Degenaar, R. Wijnands, E. F. Brown, D. Altamirano, E. M. Cackett, J. Fridriksson, J. Homan, C. O. Heinke, J. M. Miller, D. Pooley, G. R. Sivakoff
Physics and Astronomy Faculty Research Publications
The transient neutron star low-mass X-ray binary and 11 Hz X-ray pulsar IGR J17480-2446 in the globular cluster Terzan 5 exhibited an 11 week accretion outburst in 2010. Chandra observations performed within five months after the end of the outburst revealed evidence that the crust of the neutron star became substantially heated during the accretion episode and was subsequently cooling in quiescence. This provides the rare opportunity to probe the structure and composition of the crust. Here, we report on new Chandra observations of Terzan 5 that extend the monitoring to sime2.2 yr into quiescence. We find that the thermal …
An X-Ray-Uv Correlation In Cen X-4 During Quiescence, E. M. Cackett, E. F. Brown, N. Degenaar, J. M. Miller, M. Reynolds, R. Wijnands
An X-Ray-Uv Correlation In Cen X-4 During Quiescence, E. M. Cackett, E. F. Brown, N. Degenaar, J. M. Miller, M. Reynolds, R. Wijnands
Physics and Astronomy Faculty Research Publications
Quiescent emission from the neutron star low-mass X-ray binary Cen X-4 is seen to be variable on time-scales from hundreds of seconds to years, suggesting that at least in this object, low-level accretion is important during quiescence. Here, we present results from recent XMM-Newton and Swift observations of Cen X-4, where the X-ray flux (0.5-10 keV) varies by a factor of 6.5 between the brightest and faintest states. We find a positive correlation between the X-ray flux and the simultaneous near-ultraviolet (UV) flux, where as there is no significant correlation between the X-ray and simultaneous optical (V, B) fluxes. This …