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Burst-Disk Interaction in 4U 1636-536 as Observed by NICER

Güver, Tolga and Bostancı, Z. Funda and Boztepe, Tuğba and Göğüş, Ersin and Bult, Peter and Kashyap, Unnati and Chakraborty, Manoneeta and Ballantyne, David R. and Ludlam, R. M. and Malacaria, C. and Jaisawal, Gaurava K. and Strohmayer, Tod E. and Guillot, Sebastien and Ng, Mason (2022) Burst-Disk Interaction in 4U 1636-536 as Observed by NICER. Astrophysical Journal, 935 (2). p. 154. ISSN 0004-637X. doi:10.3847/1538-4357/ac8106.

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We 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 f_a 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.

Item Type:Article
Related URLs:
URLURL TypeDescription Article
Güver, Tolga0000-0002-3531-9842
Bostancı, Z. Funda0000-0002-5665-3452
Boztepe, Tuğba0000-0002-4729-1592
Göğüş, Ersin0000-0002-5274-6790
Bult, Peter0000-0002-7252-0991
Kashyap, Unnati0000-0001-6530-0221
Chakraborty, Manoneeta0000-0002-9736-9538
Ballantyne, David R.0000-0001-8128-6976
Ludlam, R. M.0000-0002-8961-939X
Malacaria, C.0000-0002-0380-0041
Jaisawal, Gaurava K.0000-0002-6789-2723
Strohmayer, Tod E.0000-0001-7681-5845
Guillot, Sebastien0000-0002-6449-106X
Ng, Mason0000-0002-0940-6563
Additional Information:We thank the referee for their very valuable and constructive comments. T.G. has been supported in part by the Scientific and Technological Research Council (TÜBİTAK), 119F082, and the Turkish Republic, Presidency of Strategy and Budget, project 2016K121370. This work was supported by NASA through the NICER mission and the Astrophysics Explorers Program. P.B. acknowledges support from the CRESST II cooperative agreement (80GSFC21M0002). R.M.L. acknowledges the support of NASA through Hubble Fellowship Program grant HST-HF2-51440.001. S.G. acknowledges the support of the CNES. This research has made use of software provided by the High Energy Astrophysics Science Archive Research Center (HEASARC), which is a service of the Astrophysics Science Division at NASA/GSFC and the High Energy Astrophysics Division of the Smithsonian Astrophysical Observatory. This paper includes data publicly available from the AstroSat mission of the Indian Space Research Organisation (ISRO), archived at the Indian Space Science Data Centre (ISSDC). M.C. acknowledges support from ISRO under the AstroSat archival data utilization program (DS 2B-13013(2)/4/2020-Sec.2). Facility: NICER, AstroSat, NuSTAR - . Software: HEASoft, XSPEC, Sherpa, CIAO, Astropy.
Funding AgencyGrant Number
Turkish Strategy and Budget Presidency2016K121370
Hubble Fellowship ProgramHST-HF2-51440.001
Astrophysics Explorers ProgramUNSPECIFIED
High Energy Astrophysics Science Archive Research Center (HEASARC)UNSPECIFIED
Indian Space Research Organisation (ISRO)UNSPECIFIED
AstroSat archival data utilization program (DS 2B-13013(2)/4/2020-Sec.2)UNSPECIFIED
Issue or Number:2
Record Number:CaltechAUTHORS:20220908-184431283
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:116657
Deposited By: Donna Wrublewski
Deposited On:07 Sep 2022 22:32
Last Modified:08 Sep 2022 18:45

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