December 20, 2023

Demographics of Tidal Disruption Events with L-Galaxies: I. Volumetric TDE rates and the abundance of Nuclear Star Clusters

Polkas, Markos; Bonoli, Silvia; Bortolas, Elisa; Izquierdo-Villalba, David; Sesana, Alberto; Broggi, Luca; Hoyer, Nils; Spinoso, Daniele Stars can be ripped apart by tidal forces in the vicinity of a massive black hole, causing luminous flares classified as tidal disruption events (TDEs). These events could be contributing to the mass growth of intermediate-mass black holes, while new samples from ongoing transient surveys can provide useful information on this unexplored growth channel.

March 24, 2023

Gravitational waves from an eccentric population of primordial black holes orbiting Sgr A⋆

Bondani, Stefano; Bonetti, Matteo; Broggi, Luca; Haardt, Francesco; Sesana, Alberto; Dotti, Massimo. Primordial black holes (PBH), supposedly formed in the very early Universe, have been proposed as a possible viable dark matter candidate. In this work we characterize the expected gravitational wave (GW) losses from a population of PBHs orbiting Sgr A⋆, the super-massive black hole at the Galactic center, and assess the signal detectability by the planned space-borne interferometer LISA and by the proposed next generation space-borne interferometer μAres.

March 8, 2023

Partial stellar tidal disruption events and their rates

Bortolas, Elisa; Ryu, Taeho; Broggi, Luca; Sesana, Alberto. Tidal disruption events (TDEs) of stars operated by massive black holes (MBHs) will be detected in thousands by upcoming facilities such as the Vera Rubin Observatory. In this work, we assess the rates of standard total TDEs, destroying the entire star, and partial TDEs, in which a stellar remnant survives the interaction, by solving 1-D Fokker-Planck equations. Our rate estimates are based on a novel definition of the loss cone whose size is commensurate to the largest radius at which partial disruptions can occur, as motivated by relativistic hydrodynamical simulations.