Using a suite of fully relativistic hydrodynamic simulations applied to main-sequence stars with realistic internal density profiles, we examine full and partial tidal disruptions across a wide range of black hole mass ($10^{ 5}\leq M_{ \rm BH}/\mathrm{ M}_{ \odot}\leq 5\times 10^{ 7}$) and stellar mass ($0.3 \leq M_{ \star} /\mathrm{ M}_{ \odot}\leq 3$) as larger $M_{ \rm BH}$ leads to stronger relativistic effects. For fixed $M_{ \star}$, as $M_{ \rm BH}$ increases, the ratio of the maximum pericenter distance yielding full disruptions ($\mathcal{ R}_{ \rm t}$) to its Newtonian prediction rises rapidly, becoming triple the Newtonian value for $M_{ \rm BH} = 5\times10^{ 7}~{ \rm M}_\odot$, while the ratio of the energy width of the stellar debris for full disruptions to the Newtonian prediction decreases steeply, resulting in a factor of two correction at $M_{ \rm BH} = 5 \times 10^7~{ \rm M}_\odot$. We find that for partial disruptions, the fractional remnant mass for a given ratio of the pericenter to $\mathcal{ R}_{ \rm t}$ is higher for larger $M_{ \rm BH}$. These results have several implications. As $M_{ \rm BH}$ increases above $\sim 10^7~{ \rm M}_\odot$, the cross section for complete disruptions is suppressed by competition with direct capture. However, the cross section ratio for partial to complete disruptions depends only weakly on $M_{ \rm BH}$. The relativistic correction to the debris energy width delays the time of peak mass-return rate and diminishes the magnitude of the peak return rate. For $M_{ \rm BH} \gtrsim 10^7~{ \rm M}_\odot$, the $M_{ \rm BH}$-dependence of the full disruption cross section and the peak mass-return rate and time is influenced more by relativistic effects than by Newtonian dynamics.
Categories: astro-ph.HE astro-ph.GA astro-ph.SR