X-ray bursts as a probe of the corona: the case of XRB 4U 1636-536
Abstract
To investigate the possible cooling of the corona by soft X-rays bursts, we have studied 114 bursts embedded in the known X-ray evolution of 4U 1636-536. We have grouped these bursts according to the ratio of the flux in the 1.5-12 keV band with respect to that in the 15-50 keV band, as monitored by Rossi X-ray Timing Explorer/All Sky Monitor and Swift/Burst Alert Telescope, respectively. We have detected a shortage at hard X-rays while bursting. This provides hints for a corona cooling process driven by soft X-rays fed by the bursts that occurred on the surface of neutron star. The flux shortage at 30-50 keV has a time lag of 2.4 ± 1.5 s with respect to that at 2-10 keV, which is comparable to that of 0.7 ± 0.5 s reported in bursts of IGR 17473-2721. We comment on the possible origin of these phenomena and on the implications for the models on the location of the corona.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2013
- DOI:
- 10.1093/mnras/stt625
- arXiv:
- arXiv:1304.5371
- Bibcode:
- 2013MNRAS.432.2773J
- Keywords:
-
- stars: coronae;
- stars: neutron;
- X-rays: binaries;
- X-rays: individual: 4U 1636-536;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 6 pages, 9 figures, accepted by MNRAS