Skip to content
DraconiticResearch
Search Sources API
201,683 studies31 sourcesUpdated 6 min ago
Peer-reviewedCC BY 4.0The Astrophysical Journal

Accretion Geometry of the Ultracompact X-Ray Binary 4U 1543–624: AstroSat View

  • Subhasish Das1
  • Raj Kumar2
  1. 1Guru Ghasidas Vishwavidyalaya
  2. 2Xiamen University
Open at sourcePDFDOICite

Abstract

We present a broadband spectral analysis of the ultracompact X-ray binary (UCXB) 4U 1543–624, using AstroSat observation during 2017 March. The X-ray spectra in the 0.5–25.0 keV energy band are well described by a combination of a multicolor disk component, a single-temperature blackbody emission from the NS surface/BL, a Comptonization component, and a relativistically broad O VIII Ly α emission line. During this observation, a cool disk with kT in ∼ 0.6 keV reached toward the innermost stable circular orbit (ISCO) at a low accretion rate m ̇ / m ̇ E d d ≃ 0.016 . Furthermore, the presence of an O VIII Ly α line confirms the existence of an O-rich accretion disk extending to the ISCO, which challenges the standard accretion disk model. We discussed our results within the framework of a standard accretion disk and advection-dominated accretion flows. Our results are compatible with the condensation-fed inner accretion flows.

Related

  1. Spectral evolution of NS binary system GX 349+2 using AstroSat observations
    Garima Tyagi, Suchismito Chattopadhyay, Sree Bhattacherjee +3
    arXivPreprintarXiv licenceFull textHigh-energy astrophysicsarXiv
  2. Electromagnetic Counterparts of Stellar-mass Binary Black Hole Mergers in AGN Accretion Disks: Theoretical Models and Observational Status
    Lei He, Liang-Gui Zhu, Ken Chen +4
    arXivPreprintCC BY 4.0Full textCosmologyHigh-energy astrophysicsarXiv
  3. Magnetized accretion onto rapidly spinning binary black holes: mini-disk thermodynamics, magnetic transport, and dual jets
    Luciano Combi, Manuela Campanelli, Sean M. Ressler +2
    arXivPreprintCC BY 4.0Full textHigh-energy astrophysicsGravitation & general relativityarXiv
  4. Preferential accretion onto eccentric and unequal binary black holes
    Stanislav DeLaurentiis, Zoltán Haiman, Magdalena Siwek
    arXivPreprintarXiv licenceFull textHigh-energy astrophysicsarXiv
  5. AT 2016blu: Accretion-powered Outbursts in a Luminous Blue Variable and Compact Object Binary
    Mojgan Aghakhanloo, Núria Torres-Albà, Nathan Smith +33
    The Astrophysical JournalPeer-reviewedCC BY 4.0Full textSolar & stellar physicsIOP/AASCrossref

Cite

BibTeXRIS
BibTeX
@article{das2026accretion,
  title = {{Accretion Geometry of the Ultracompact X-Ray Binary 4U 1543–624: AstroSat View}},
  author = {Subhasish Das and Raj Kumar},
  journal = {The Astrophysical Journal},
  year = {2026},
  month = oct,
  doi = {10.3847/1538-4357/aea837},
  url = {https://iopscience.iop.org/article/10.3847/1538-4357/aea837},
  note = {CC BY 4.0},
}
RIS
TY  - JOUR
TI  - Accretion Geometry of the Ultracompact X-Ray Binary 4U 1543–624: AstroSat View
AU  - Subhasish Das
AU  - Raj Kumar
PY  - 2026
DA  - 2026/10/19
JO  - The Astrophysical Journal
DO  - 10.3847/1538-4357/aea837
UR  - https://iopscience.iop.org/article/10.3847/1538-4357/aea837
AB  - We present a broadband spectral analysis of the ultracompact X-ray binary (UCXB) 4U 1543–624, using AstroSat observation during 2017 March. The X-ray spectra in the 0.5–25.0 keV energy band are well described by a combination of a multicolor disk component, a single-temperature blackbody emission from the NS surface/BL, a Comptonization component, and a relativistically broad O VIII Ly α emission line. During this observation, a cool disk with kT in ∼ 0.6 keV reached toward the innermost stable circular orbit (ISCO) at a low accretion rate m ̇ / m ̇ E d d ≃ 0.016 . Furthermore, the presence of an O VIII Ly α line confirms the existence of an O-rich accretion disk extending to the ISCO, which challenges the standard accretion disk model. We discussed our results within the framework of a standard accretion disk and advection-dominated accretion flows. Our results are compatible with the condensation-fed inner accretion flows.
SN  - 0004-637X
SN  - 1538-4357
ER  -