Disk instability and the time-dependent X-ray emission from the intermediate polar GK persei

According to the disk instability model for the 1981-1989 outbursts of the intermediate polar GK Per, the mass accretion rate at the inner disk edge (Min) varies from ∼2 × 10¹⁶ g s^-1 in quiescence to ∼3 × 10¹⁹ g s^-1 in outburst, while the mass transfer rate from the companion weakly fluctuates around 10¹⁸ g s^-1. During quiescence, the postshock region of the accretion column is characterized by optically thin bremsstrahlung emission with a …