Discovery of a new flaring class in GRS 1915+105 using AstroSat
Abstract
Highly variable Black Hole X-ray Binary (BHXB) GRS~1915+105 has shown many flaring classes when the source oscillates between the High Soft state (HS) and the Hard Intermediate state (HIMS) with a transition time of less than 10 s. The X-ray flux is anti-correlated with hardness ratio (HR2) during these X-ray flaring classes. We have analyzed Astrosat/LAXPC \& SXT data and report here a new X-ray flaring class named class when the source oscillates between two HS states (the power-law index is always greater than 4) with transition time around 50 s. The X-ray flux is correlated with hardness ratio. This class is quasi-regular, and we have detected High Frequency Quasi Periodic Oscillations (HFQPOs) around 70 Hz during this new flaring class. The accretion rate changes by a factor of three over the burst cycle. We report here the results of our extensive study of spectral and timing characteristics of this new class.
Keywords
Cite
@article{arxiv.2504.00892,
title = {Discovery of a new flaring class in GRS 1915+105 using AstroSat},
author = {Ruchika Dhaka and JS Yadav and Ranjeev Misra and Pankaj Jain},
journal= {arXiv preprint arXiv:2504.00892},
year = {2025}
}
Comments
12 pages, 7 figures