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Bibliographic Details
Main Authors: Tomaselli, Giovanni Maria, Caputo, Andrea
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2509.03568
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author Tomaselli, Giovanni Maria
Caputo, Andrea
author_facet Tomaselli, Giovanni Maria
Caputo, Andrea
contents The orbits of stars around Sgr A*, the Milky Way's supermassive black hole, provide a unique laboratory for testing its environment with unprecedented precision. In this work, we compute the apsidal precession induced by extended matter distributions through Lagrange's equations and compare it with the measured precession of S2, reproducing and extending GRAVITY's constraints. In particular, we push bounds on boson clouds to larger gravitational couplings $α$ and to the second-fastest superradiant mode. We also show that environments with mass of order $1\%$ of Sgr A* drive stellar orbits to decay by dynamical friction within a few Myr. The inner star cluster is however efficiently replenished, masking this effect observationally. We also show that orbital resonances from boson clouds have no impact on relevant timescales. While S2 currently provides the cleanest dataset, our framework is readily applicable to other stars that we identify as particularly promising, whose orbits will be measured with increasing accuracy, opening up new opportunities to probe the environment of Sgr A*.
format Preprint
id arxiv_https___arxiv_org_abs_2509_03568
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Probing dense environments around Sgr A* with S-stars dynamics
Tomaselli, Giovanni Maria
Caputo, Andrea
Astrophysics of Galaxies
General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
The orbits of stars around Sgr A*, the Milky Way's supermassive black hole, provide a unique laboratory for testing its environment with unprecedented precision. In this work, we compute the apsidal precession induced by extended matter distributions through Lagrange's equations and compare it with the measured precession of S2, reproducing and extending GRAVITY's constraints. In particular, we push bounds on boson clouds to larger gravitational couplings $α$ and to the second-fastest superradiant mode. We also show that environments with mass of order $1\%$ of Sgr A* drive stellar orbits to decay by dynamical friction within a few Myr. The inner star cluster is however efficiently replenished, masking this effect observationally. We also show that orbital resonances from boson clouds have no impact on relevant timescales. While S2 currently provides the cleanest dataset, our framework is readily applicable to other stars that we identify as particularly promising, whose orbits will be measured with increasing accuracy, opening up new opportunities to probe the environment of Sgr A*.
title Probing dense environments around Sgr A* with S-stars dynamics
topic Astrophysics of Galaxies
General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2509.03568