Speaker
Description
We present the results of a spectral and timing analysis of the X-ray emission from the actively accreting supermassive black hole in RX J1301.9+2747, which exhibits quasi-periodic X-ray burst-like eruptions. To investigate the features of the X-ray spectrum formation in this source during the bursts, data from ASCA, ROSAT, XMM-Newton, and NICER observations were used with a Comptonization model. We detected an increase of the photon index Γ with the mass accretion rate Ṁ, with the index saturating at Γsat = 2.7 ± 0.1 at high Ṁ values during the flare peaks. This Γ–Ṁ correlation was used to estimate the mass of the supermassive black hole in RX J1301.9+2747, M ~ 5×10^6 M⊙, using a scaling method with HLX-1 in ESO 243-49, OJ 287, and 1H 0707-495 as reference sources. We also estimated the black hole mass in RX J1301.9+2747 using an alternative method for the source's quiescent state, applying power spectral density method, in which we estimate the size of the Compton cloud (CC) as LCC$~ 5 × 10^{11} cm$. Assuming this LCC value is close to the Schwarzschild radius of the black hole, we confirmed that the mass of the supermassive black hole at the center of RX J1301.9+2747 is on the order of $2 × 10^6 M⊙$.
