Zobrazeno 1 - 10
of 60
pro vyhledávání: '"Santabrata Das"'
Publikováno v:
The Astrophysical Journal Letters, Vol 971, Iss 1, p L21 (2024)
We report the results of first ever spectropolarimetric analyses of the Galactic ultraluminous X-ray pulsar Swift J0243.6+6124 during the 2023 outburst using quasi-simultaneous IXPE, NICER, and NuSTAR observations. A pulsation of period ∼9.79 s is
Externí odkaz:
https://doaj.org/article/e0b6e2af5958476cbbde628ff9d91864
Autor:
Samik Mitra, Santabrata Das
Publikováno v:
The Astrophysical Journal, Vol 971, Iss 1, p 28 (2024)
We investigate the global structure of the general relativistic magnetohydrodynamic (GRMHD) accretion flows around Kerr black holes containing shock waves, where the disk is threaded by radial and toroidal magnetic fields. We self-consistently solve
Externí odkaz:
https://doaj.org/article/5f9f72438b7f49028b35d0fde3d630bc
Autor:
Santabrata Das, Anuj Nandi, C S Stalin, Suvendu Rakshit, Indu Kalpa Dihingia, Swapnil Singh, Ramiz Aktar, Samik Mitra
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 514:1940-1951
We study the relativistic, inviscid, advective accretion flow around the black holes and investigate a key feature of the accretion flow, namely the shock waves. We observe that the shock-induced accretion solutions are prevalent and such solutions a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4f5cb884916e9f2c9c1763be40e399e3
https://doi.org/10.1093/mnras/stac1398
https://doi.org/10.1093/mnras/stac1398
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 512:2508-2524
We present a comprehensive temporal and spectral analysis of the ‘softer’ variability classes (i.e. θ, β, δ, ρ, κ, ω and γ) of the source GRS 1915+105 observed by AstroSat during the 2016−2021 campaign. Wide-band (3−60 keV) timing stud
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::49a0e7f7878a4e4ee9e6779c15b65391
https://doi.org/10.1093/mnras/stac615
https://doi.org/10.1093/mnras/stac615
We present a novel approach to study the global structure of steady, axisymmetric, advective, geometrically thin, magnetohydrodynamic (MHD) accretion flow around black holes in full general relativity (GR). Considering ideal MHD conditions and relati
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e6bb65ea0d325f99b0e3c2130d4d733b
http://arxiv.org/abs/2204.01412
http://arxiv.org/abs/2204.01412
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 496:3043-3059
We study the two-temperature magnetized advective accretion flow around the Kerr black holes. During accretion, ions are heated up due to viscous dissipation, and when Coulomb coupling becomes effective, they transfer a part of their energy to the el
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4209cfff079b89bd3f693999af1e62f9
https://doi.org/10.1093/mnras/staa1687
https://doi.org/10.1093/mnras/staa1687
We study the properties of a low-angular momentum, inviscid, advective accretion flow in a deformed Kerr spacetime under the framework of general theory of relativity. We solve the governing equations that describe the flow motion in terms of input p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5b62ca341e44320e5fd6c4cf9ef40701
http://arxiv.org/abs/2202.10863
http://arxiv.org/abs/2202.10863
In this letter, we develop a model formalism to study the structure of a relativistic, viscous, optically thin, advective accretion flow around a rotating black hole in presence of radiative coolings. We use this model to examine the physical paramet
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c071e411edd4ac6a576d3ff14a00b514
http://arxiv.org/abs/2108.02973
http://arxiv.org/abs/2108.02973
Autor:
M. C. Ramadevi, Samir Mandal, Anuj Nandi, Santabrata Das, V. K. Agrawal, Tilak Katoch, H. Sreehari
We report the results of AstroSat observations of GRS 1915$+$105 obtained using 100 ks guaranteed-time (GT) during the soft state. The Color-Color Diagram (CCD) indicates a variability class of $\delta$ with the detection of High Frequency QPO (HFQPO
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4eb89ac4b6ff25dbcfb145382574587b
http://arxiv.org/abs/2010.03782
http://arxiv.org/abs/2010.03782
Publikováno v:
Physical Review D. 102
We study the properties of the relativistic, steady, axisymmetric, low angular momentum, inviscid, advective, geometrically thin accretion flow in a Kerr-Taub-NUT (KTN) spacetime which is characterized by the Kerr parameter ($a_{\rm k}$) and NUT para
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::77c91c5ae0ea693782830c7ad7b07146
https://doi.org/10.1103/physrevd.102.023012
https://doi.org/10.1103/physrevd.102.023012