Stellar Tidal Disruption Events by Direct Collapse Black Holes

We analyze the early growth stage of direct-collapse black holes (DCBHs) with $\sim {10}^5{\mathrm{M}}_{\odot }$, which are formed by collapse of supermassive stars in atomic-cooling halos at $z\gtrsim 10$. A nuclear accretion disk around a newborn DCBH is gravitationally unstable and fragments into clumps with a few $10{\mathrm{M}}_{\odot }$ at $\sim 0.01-0.1\mathrm{p}\mathrm{c}$ from the center. Such clumps evolve into massive population III stars with a few $10-100{\mathrm{M}}_{\odot }$ via successive gas accretion and a nuclear star cluster is formed. Radiative and mechanical feedback from an inner slim disk and the star cluster will significantly reduce the gas accretion rate onto the DCBH within $\sim 10^6
\rm yr$. Some of the nuclear stars can be scattered onto the loss cone orbits also within $\lesssim {10}^6\mathrm{y}\mathrm{r}$ and tidally disrupted by the central DCBH. The jet luminosity powered by such tidal disruption events can be $L_{\rm j} \gtrsim 10^{50} \ \rm erg \ s^{-1}$. The prompt emission will be observed in X-ray bands with a peak duration of $\delta t_{\rm obs} \sim 10^{5-6} \ (1+z)
\rm s$followedbyatail$\propto t_{\rm obs}^{-5/3}$, which can be detectable by Swift BAT and eROSITA even from $z\sim 20$. Follow-up observations of the radio afterglows with, e.g., eVLA and the host halos with JWST could probe the earliest AGN feedback from DCBHs.