Accretion Properties and Estimation of Spin of Galactic Black Hole Candidate Swift J1728.9-3613 with NuSTAR during its 2019 outburst

Abstract

Black hole X-ray binaries (BHXRBs) play a crucial role in understanding the accretion of matter onto a black hole. Here, we focus on exploring the transient BHXRB \source~discovered by Swift/BAT and MAXI/GSC during its January 2019 outburst. We present measurements on its accretion properties, long time-scale variability, and spin. To probe these properties we make use of several NICER observations and an unexplored data set from NuSTAR, as well as long term light curves from MAXI/GSC. In our timing analysis we provide estimates of the cross-correlation functions between light curves in various energy bands. In our spectral analysis we employ numerous phenomenological models to constrain the parameters of the system, including flavours of the relativistic reflection model Relxill to model the Fe K$\alpha$ line and the $>15$ keV reflection hump. Our analysis reveals that: (i) Over the course of the outburst the total energy released was $\sim 5.2\times 10^{44}$~ergs, corresponding to roughly 90\% the mass of Mars being devoured. (ii) We find a continuum lag of $8.4\pm 1.9$ days between light curves in the $2-4$ keV and $10-20$ keV bands which could be related to the viscous inflow time-scale of matter in the standard disc. (iii) Spectral analysis reveals a spin parameter of $\sim 0.6-0.7$ with an inclination angle of $\sim 45^{\circ }-70^{\circ }$, and an accretion rate during the NuSTAR observation of $\sim 17\%L_{\mathrm{Edd}}$.

13 pages 6 figures, Accepted for publication in MNRAS, Comments are welcome

References in corpus (16)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• X-ray Properties of Black-Hole Binaries
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• Modelling the behaviour of accretion flows in X-ray binaries
• The role of the reflection fraction in constraining black hole spin
• A Determination of the Spin of the Black Hole Primary in LMC X-1
• AstroSat view of MAXI J1535-571: broadband spectro-temporal features
• Failed-Transition outbursts in Black hole low-mass X-ray binaries
• An X-ray reverberation mass measurement of Cygnus X-1
• Effects of Compton Cooling on Outflow in a Two Component Accretion Flow around a Black Hole: Results of a Coupled Monte Carlo-TVD Simulation
• AstroSat Observation of X-ray Dips and State Transition in the Black Hole Candidate MAXI J1803-298
• Estimation of the black hole spin in LMC X-1 using AstroSat
• NuSTAR and Swift Observations of the Extragalactic Black Hole X-ray Binaries
• Time-domain variability properties of XTE J1650-500 during its 2001 outburst: Evidence of disc-jet connection
• The long-stable hard state of XTE J1752-223 and the disk truncation dilemma
• The development of a testbed for the X-ray Interferometer mission