1. RRI Digital Repository
  2. 04. Astronomy and Astrophysics
  3. Research Papers (A&A)
Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/8696
Full metadata record
DC FieldValueLanguage
dc.contributor.authorSuman, Shree-
dc.contributor.authorKhatua, Shuvajit-
dc.contributor.authorJadoliya, Vishal-
dc.contributor.authorGupta, Prathamesh Narayan-
dc.contributor.authorPahari, Mayukh-
dc.date.accessioned2026-03-25T06:13:54Z-
dc.date.available2026-03-25T06:13:54Z-
dc.date.issued2026-03-12-
dc.identifier.citationResearch in Astronomy and Astrophysics, 2026, Vol. 26 (5), AR No. 055009en_US
dc.identifier.issn2397-6209-
dc.identifier.urihttp://hdl.handle.net/2289/8696-
dc.descriptionRestricted Access. An open-access version is available at arXiv.org (one of the alternative locations)en_US
dc.description.abstractThe origin of the large-amplitude, quasi-periodic X-ray flux variations in several classes of the Galactic microquasar GRS 1915+105 remains unresolved. We address this issue through flux-resolved, broadband (0.8–20 keV) spectral modeling and simultaneous covariance spectral analysis during two κ and two ω class observations using AstroSat/SXT and LAXPC. The lightcurves show strong, quasi-periodic oscillations involving rapid transitions between bright bursts and deep dips on timescales of a few tens of seconds. Flux-resolved spectroscopy indicates that high-flux intervals in both classes are dominated by a hot, optically thick accretion disk with steep Comptonized emission, whereas low-flux intervals correspond to a cooler or partially recessed disk and a harder coronal continuum. These transitions involve a systematic 1–2 keV drop in disk temperature and a pronounced hardening of the Comptonized component, with flux reductions of up to a factor of five. Using covariance spectra across 0.015–5 Hz, we show that the rapid coherent variability arises almost entirely from the disk, which exhibits strong energy-dependent variations, while the Comptonized component contributes minimally. The combined results suggest that radiation-pressure-driven structural changes in the disk, with a slower coronal response, produce the observed oscillations, consistent with cyclic disk evacuation and refilling in the κ and ω classes.en_US
dc.language.isoenen_US
dc.publisherResearch in Astronomy and Astrophysicsen_US
dc.relation.urihttps://doi.org/10.48550/arXiv.2602.11876en_US
dc.relation.urihttp://doi.org/10.1088/1674-4527/ae43d9en_US
dc.rights© 2026. National Astronomical Observatories, CAS and IOP Publishing Ltden_US
dc.titleSpectro-timing Origin of Large Amplitude X-Ray Variability in GRS 1915+105 Using AstroSat/LAXPC and SXTen_US
dc.typeArticleen_US
Appears in Collections:Research Papers (A&A)

Files in This Item:
File Description SizeFormat 
2026_Research in Astronomy and Astrophysics_Vol 26 (5)_AR No 055009.pdf
  Restricted Access		Restricted Access2.41 MBAdobe PDFView/Open Request a copy
Show simple item record


Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.