ON THE RELATIVE RATES OF DECAY OF THE OPTICAL AND SOFT-X-RAY FLUXES IN DWARF NOVA OUTBURSTS

We present time-dependent computations utilizing the accretion disk li mit cycle instability to model the decay of the flux in dwarf nova out bursts. In particular, we model the optical and 0.1 keV fluxes in an a ttempt to account for recent findings by Ponman et al. The e-folding d ecay times of similar to 3 days for the optical and similar to 1 day f or the soft X-ray/EUV in an outburst of SS Cygni are naturally account ed for in the model by the action of the cooling front which enacts th e transition between the high and low states in the accretion disk. Th e difference in timescales; between V and EUV stems from the fact that , roughly speaking, the optical Bw: samples the surface area of the ho t part of the accretion disk, whereas the EUV samples the mass of the hot part of the accretion disk.