A stochastic propagation model to the energy dependent rapid temporal behaviour of Cygnus X-1 as observed by AstroSat in the hard state
- Title
- A stochastic propagation model to the energy dependent rapid temporal behaviour of Cygnus X-1 as observed by AstroSat in the hard state
- Creator
- Maqbool B.; Mudambi S.P.; Misra R.; Yadav J.S.; Gudennavar S.B.; Bubbly S.G.; Rao A.; Jogadand S.; Patil M.K.; Bhattacharyya S.; Singh K.P.
- Description
- We report the results from analysis of six observations of Cygnus X-1 by Large Area X-ray Proportional Counter (LAXPC) and Soft X-ray Telescope (SXT) onboard AstroSat, when the source was in the hard spectral state as revealed by the broad-band spectra. The spectra obtained from all the observations can be described by a single-temperature Comptonizing region with disc and reflection components. The event mode data from LAXPC provides unprecedented energy dependent fractional root mean square (rms) and time-lag at different frequencies which we fit with empirical functions.We invoke a fluctuation propagation model for a simple geometry of a truncated disc with a hot inner region. Unlike other propagation models, the hard X-ray emission (>4 keV) is assumed to be from the hot inner disc by a single-temperature thermal Comptonization process. The fluctuations first cause a variation in the temperature of the truncated disc and then the temperature of the inner disc after a frequency dependent time delay.We find that the model can explain the energy dependent rms and time-lag at different frequencies. 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
- Source
- Monthly Notices of the Royal Astronomical Society, Vol-486, No. 2, pp. 2964-2975.
- Date
- 2019-01-01
- Publisher
- Oxford University Press
- Subject
- accretion, accretion discs; black hole physics -X-rays: binaries; X-rays: individual: Cygnus X-1.
- Coverage
- Maqbool B., Inter-University Centre for Astronomy and Astrophysics, Ganeshkind, Pune, 411007, India; Mudambi S.P., Department of Physics and Electronics, CHRIST (Deemed to Be University), Hosur Road, Bengaluru, 560029, India; Misra R., Inter-University Centre for Astronomy and Astrophysics, Ganeshkind, Pune, 411007, India; Yadav J.S., Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India; Gudennavar S.B., Department of Physics and Electronics, CHRIST (Deemed to Be University), Hosur Road, Bengaluru, 560029, India; Bubbly S.G., Department of Physics and Electronics, CHRIST (Deemed to Be University), Hosur Road, Bengaluru, 560029, India; Rao A., Department of Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, Southampton, SO17 1BJ, United Kingdom; Jogadand S., Swami Ramanand Teerth Marathwada University, Nanded, 431 606, India; Patil M.K., Swami Ramanand Teerth Marathwada University, Nanded, 431 606, India; Bhattacharyya S., Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India; Singh K.P., Indian Institute of Science Education and Research Mohali, Knowledge City, Sector 81 SAS Nagar, Manauli, 140306, India
- Rights
- All Open Access; Bronze Open Access; Green Open Access
- Relation
- ISSN: 358711; CODEN: MNRAA
- Format
- Online
- Language
- English
- Type
- Article
Collection
Citation
Maqbool B.; Mudambi S.P.; Misra R.; Yadav J.S.; Gudennavar S.B.; Bubbly S.G.; Rao A.; Jogadand S.; Patil M.K.; Bhattacharyya S.; Singh K.P., “A stochastic propagation model to the energy dependent rapid temporal behaviour of Cygnus X-1 as observed by AstroSat in the hard state,” CHRIST (Deemed To Be University) Institutional Repository, accessed February 26, 2025, https://archives.christuniversity.in/items/show/16693.