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Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/8006
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dc.contributor.authorGhosh, Tanuman-
dc.contributor.authorRana, Vikram-
dc.contributor.authorBachetti, Matteo-
dc.date.accessioned2022-10-28T04:37:15Z-
dc.date.available2022-10-28T04:37:15Z-
dc.date.issued2022-10-10-
dc.identifier.citationThe Astrophysical Journal, 2022, Vol. 98, p76en_US
dc.identifier.issn0004-637X-
dc.identifier.issn1538-4357 (Online)-
dc.identifier.urihttp://hdl.handle.net/2289/8006-
dc.descriptionOpen Accessen_US
dc.description.abstractWe report the detection of flaring events in NGC 4395 ULX1, a nearby ultraluminous X-ray source (ULX), for the first time, using recent XMM-Newton observations. The flaring episodes are spectrally harder than the steady-emission intervals, resulting in higher fractional variability in the high-energy regime. A thin Keplerian and a slim accretion disk provide the best-fit continuum for XMM-Newton spectra. All observations show a broad hump-like feature around ∼0.9 keV, which can be associated with a collection of blended emission lines, and suggests the presence of a wind or outflow in this ULX through comparison with other ULXs that show a similar feature. The flaring spectra correspond to higher slim-disk temperatures due to a higher mass accretion rate under an advection-dominated accretion scenario. The luminosity–temperature (L-T) values in different flux states show a positive trend. When characterized with a power-law relation, the L-T profile is broadly consistent with both L ∝ T2 and L ∝ T4 relations for the analyzed data. The empirical predictions for a slim accretion disk in the case of super-Eddington accretion onto a stellar-mass compact object is L ∝ T2, which is a possible scenario in ULX1. The origin of the flaring events is understood as an intrinsic change in accretion rate or presence of variable clumpy wind in the inner region of the accretion disk.en_US
dc.language.isoenen_US
dc.publisherIOP Publishing Ltd for the American Astrophysical Societyen_US
dc.relation.urihttps://ui.adsabs.harvard.edu/abs/2022ApJ...938...76G/abstracten_US
dc.relation.urihttps://arxiv.org/abs/2202.01432en_US
dc.relation.urihttps://doi.org/10.3847/1538-4357/ac8f8fen_US
dc.rights2022 The Author(s)en_US
dc.subjectUltraluminous x-ray sourcesen_US
dc.subjectX-ray binary starsen_US
dc.subjectAstrophysics - High Energy Astrophysical Phenomenaen_US
dc.titleHard X-Ray Flares and Spectral Variability in NGC 4395 ULX1en_US
dc.typeArticleen_US
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