Preprint article · Journal article
Burst–Disk Interaction in 4U 1636–536 as Observed by NICER
Istanbul University1
NASA Goddard Space Flight Center2
CNRS3
Massachusetts Institute of Technology4
Sabanci University5
University of Maryland, College Park6
Indian Institute of Technology Indore7
Georgia Institute of Technology8
California Institute of Technology9
Universities Space Research Association10
Astrophysics and Atmospheric Physics, Department of Space Research and Technology, Technical University of Denmark11
Department of Space Research and Technology, Technical University of Denmark12
...and 2 moreWe present the detection of 51 thermonuclear X-ray bursts observed from 4U 1636–536 by the Neutron Star Interior Composition Explorer (NICER) over the course of a 3 yr monitoring campaign. We perform time-resolved spectroscopy for 40 of these bursts and show the existence of a strong soft excess in all the burst spectra.
The excess emission can be characterized by the use of a scaling factor (the fa method) to the persistent emission of the source, which is attributed to the increased mass accretion rate onto the neutron star due to Poynting–Robertson drag. The soft excess emission can also be characterized by the use of a model taking into account the reflection of the burst emission off the accretion disk.
We also present time-resolved spectral analysis of five X-ray bursts simultaneously observed by NICER and AstroSat, which confirm the main results with even greater precision. Finally, we present evidence for Compton cooling using seven X-ray bursts observed contemporaneously with NuSTAR, by means of a correlated decrease in the hard X-ray lightcurve of 4U 1636–536 as the bursts start.
Language: | English |
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Publisher: | The American Astronomical Society |
Year: | 2022 |
ISSN: | 15384357 and 0004637x |
Types: | Preprint article and Journal article |
DOI: | 10.3847/1538-4357/ac8106 |
ORCIDs: | Jaisawal, Gaurava K. , 0000-0002-3531-9842 , 0000-0002-5665-3452 , 0000-0002-4729-1592 , 0000-0002-5274-6790 , 0000-0002-7252-0991 , 0000-0001-6530-0221 , 0000-0002-9736-9538 , 0000-0001-8128-6976 , 0000-0002-8961-939X , 0000-0002-0380-0041 , 0000-0001-7681-5845 , 0000-0002-6449-106X and 0000-0002-0940-6563 |