Unveiling the Temporal Properties of MAXI J1820+070 through AstroSat Observations
Abstract
We present here the results of the first broadband simultaneous spectral and temporal studies of the newly detected black hole binary MAXI J1820+070 as seen by Soft X-ray Telescope and Large Area X-ray Proportional Counter (LAXPC) on board AstroSat. The observed combined spectra in the energy range 0.7-80 keV were well modeled using disk blackbody emission, thermal Comptonization, and a reflection component. The spectral analysis revealed that the source was in its hard spectral state (Γ = 1.61) with a cool disk (kTin = 0.22 keV). We report the energy dependent time-lag and root mean squared (rms) variability at different frequencies in the energy range 3-80 keV using LAXPC data. We also modeled the flux variability using a single-zone stochastic propagation model to quantify the observed energy dependence of time lag and fractional rms variability, and then compared the results with that of Cygnus X-1. Additionally, we confirm the detection of a quasi-periodic oscillation with the centroid frequency at 47.7 mHz.
- Publication:
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The Astrophysical Journal
- Pub Date:
- January 2020
- DOI:
- arXiv:
- arXiv:2001.00755
- Bibcode:
- 2020ApJ...889L..17M
- Keywords:
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- Black hole physics;
- Stellar accretion disks;
- Low-mass x-ray binary stars;
- X-ray transient sources;
- Stellar accretion;
- X-ray astronomy;
- Stellar mass black holes;
- Black holes;
- 159;
- 1579;
- 939;
- 1852;
- 1578;
- 1810;
- 1611;
- 162;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted for publication in Astrophysical Journal Letters (ApJL). The article contains 8 pages, 4 figures and 1 Table. Missing reference added. Some typos corrected