Fallback Rates in Tidal Disruptions: How Far Below the Density and Shear Ceilings the Returning Debris Flows

This paper computes a grid of black hole masses from 10^5 to 10^8 solar masses disrupting a solar-type star and compares the resulting quantities with the density and shear ceilings set by the Aldred Limit on the neutron branch, rho_A = 9.72e54 g per cubic centimetre. For a black hole of a million solar masses disrupting a solar-type star, the fallback time is 41.0 days and the peak fallback rate is 2.97 solar masses per year. Across the full set of cases examined, the astrophysical quantities remain separated from the ceilings by margins of tens of orders of magnitude, so the ceilings do not participate in the dynamics of these events; their role is that of an audit scale against which claimed extremes can be checked arithmetically. All values are computed from stated assumptions and published event properties. This study is simulated and computed, not measured.