Estimating disk parameters of black hole X-ray binary MAXI J1543-564: Effect of disk irradiation

We study the central mass accretion rate and its variation with time during the outburst of X-ray transients using disk irradiation effect once the outer boundary of the disk is defined by the binary parameters. We show that the decay of the light curve and its characteristics time are well linked to the disk aspect ratio (H / R) and the binary parameters. For that we parametrize viscosity (α) parameter with H / R , assuming that there is a vertical height dependence on the energy dissipated in the disk. We derive the central accretion rate to check the sensitivity on H / R . Mass accretion rate changes notably with disk height, orbital period (P) and with binary mass function (q). For the consistency check, we apply the solution to a low mass X-ray binary (LMXRB) 4U 1543-47, whose binary parameters are dynamically measured. Finally, we estimate the unknown binary parameters of MAXI J1543-564. Using this solution for the first time we propose some predictability on P for the unknown system. The estimated value of P varies in a range from ∼10.5 to 15.5 h, when the companion mass is ∼ 0.66M_⊙ . Our estimated decay time scale is ∼ 40d with α ∼ 0.18.