I am an astrophysicist. Currently a Postdoctoral Researcher at Università degli Studi di Milano-Bicocca, in the group of prof. Alberto Sesana.
Recent Posts
Repeating partial disruptions and two-body relaxation
Broggi, Luca; Stone, Nicholas C.; Ryu, Taeho; Bortolas, Elisa; Dotti, Massimo; Bonetti, Matteo; Sesana, Alberto
Two-body relaxation may drive stars onto near-radial orbits around a massive black hole, resulting in a tidal disruption event (TDE). In some circumstances, stars are unlikely to undergo a single terminal disruption, but rather to have a sequence of many grazing encounters with the black hole. It has long been unclear what is the physical outcome of this sequence: each of these encounters can only liberate a small amount of stellar mass, but may significantly alter the orbit of the star.
read moreDemographics 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.
read moreGravitational 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.
read morePartial 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.
read moreExtreme mass ratio inspirals and tidal disruption events in nuclear clusters - I. Time-dependent rates
Broggi, Luca; Bortolas, Elisa; Bonetti, Matteo; Sesana, Alberto; Dotti, Massimo.
In this paper, we develop a computationally efficient, two-population, time-dependent Fokker–Plank approach in the two dimensions of energy and angular momentum to study the rates of tidal disruption events (TDEs), extreme mass ratio inspirals (EMRIs), and direct plunges occurring around massive black holes (MBHs) in galactic nuclei. We test our code by exploring a wide range of the astrophysically relevant parameter space, including MBH masses, galaxy central densities, and inner density slopes.
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