An effective model for the tidal disruption of satellites undergoing minor mergers with axisymmetric primaries
arXiv:2406.18652 · doi:10.1051/0004-6361/202449700
Abstract
According to the hierarchical formation paradigm, galaxies form through mergers of smaller entities and massive black holes (MBHs), if lurking at their centers, migrate to the nucleus of the newly formed galaxy, where they form binary systems. The formation and evolution of MBH binaries, and in particular their coalescence timescale, is very relevant for current and future facilities aimed at detecting the gravitational-wave signal produced by the MBH close to coalescence. While most of the studies targeting this process are based on hydrodynamic simulations, the high computational cost makes a complete parameter space exploration prohibitive. Semi-analytic approaches represent a valid alternative, but they require ad-hoc prescriptions for the mass loss of the merging galaxies in minor mergers due to tidal stripping, which is not commonly considered or at most modelled assuming very idealised geometries. In this work, we propose a novel, effective model for the tidal stripping in axisymmetric potentials, to be implemented in semi-analytic models. We validate our semi-analytic approach against N-body simulations considering different galaxy sizes, inclinations, and eccentricities, finding only a moderate dependence on the orbit eccentricity. In particular, we find that, for almost circular orbits, our model mildly overestimates the mass loss, and this is due to the adjustment of the stellar distribution after the mass is removed. Nonetheless, the model exhibits a very good agreement with simulations in all the considered conditions, and thus represents an extremely powerful addition to semi-analytic calculations.
15 pages, 8 figures, 2 tables. Accepted for publication on A&A
References in corpus (17)
- The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
- Search for an isotropic gravitational-wave background with the Parkes Pulsar Timing Array
- Formation of Massive Galaxies at High Redshift: Cold Streams, Clumpy Disks and Compact Spheroids
- The second data release from the European Pulsar Timing Array III. Search for gravitational wave signals
- The effect of galaxy mass ratio on merger--driven starbursts
- Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption
- Multiple minor mergers: formation of elliptical galaxies and constraints for the growth of spiral disks
- Black hole mergers from dwarf to massive galaxies with the NewHorizon and Horizon-AGN simulations
- Growing Massive Black Hole Pairs in Minor Mergers of Disk Galaxies
- Spatially resolved star formation and fuelling in galaxy interactions
- Shocks and angular momentum flips: a different path to feeding the nuclear regions of merging galaxies
- Galaxies lacking dark matter produced by close encounters in a cosmological simulation
- IllustrisTNG in the HSC-SSP: image data release and the major role of mini mergers as drivers of asymmetry and star formation
- Galaxy Formation as a Cosmological Tool. I: The Galaxy Merger History as a Measure of Cosmological Parameters
- Orbital dynamics and histories of satellite galaxies around Milky Way-mass galaxies in the FIRE simulations
- The role of bars on the dynamical-friction driven inspiral of massive perturbers
- A jolt to the system: ram pressure on low-mass galaxies in simulations of the Local Group