Saved in:
Bibliographic Details
Main Authors: Akiba, Tatsuya, Naoz, Smadar, Madigan, Ann-Marie
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2410.19881
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916478427594752
author Akiba, Tatsuya
Naoz, Smadar
Madigan, Ann-Marie
author_facet Akiba, Tatsuya
Naoz, Smadar
Madigan, Ann-Marie
contents The Galactic Center hosts a rotating disk of young stars between 0.05 and 0.5 pc of Sgr A*. The ``S-stars'' at a distance $<0.04$ pc, however, are on eccentric orbits with nearly isotropically distributed inclinations. The dynamical origin of the S-star cluster has remained a theoretical challenge. Using a series of $N$-body simulations, we show that a recent massive black hole merger with Sgr A* can self-consistently produce many of the orbital properties of the Galactic nuclear star cluster within 0.5 pc. A black hole merger results in a gravitational wave recoil kick, which causes the surrounding cluster to form an apse-aligned, eccentric disk. We show that stars near the inner edge of an eccentric disk migrate inward and are driven to high eccentricities and inclinations due to secular torques similar to the eccentric Kozai-Lidov mechanism. In our fiducial model, starting with a thin eccentric disk with $e = 0.3$, the initially unoccupied region within $0.04$ pc is populated with high eccentricity, high inclination S-stars within a few Myr. This dynamical channel would suggest that a black hole of mass $2^{+3}_{-1.2} \times 10^5 \ M_{\odot}$ merged with Sgr A* within the last 10 Myr.
format Preprint
id arxiv_https___arxiv_org_abs_2410_19881
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On the Formation of S-stars from a Recent Massive Black Hole Merger in the Galactic Center
Akiba, Tatsuya
Naoz, Smadar
Madigan, Ann-Marie
Astrophysics of Galaxies
The Galactic Center hosts a rotating disk of young stars between 0.05 and 0.5 pc of Sgr A*. The ``S-stars'' at a distance $<0.04$ pc, however, are on eccentric orbits with nearly isotropically distributed inclinations. The dynamical origin of the S-star cluster has remained a theoretical challenge. Using a series of $N$-body simulations, we show that a recent massive black hole merger with Sgr A* can self-consistently produce many of the orbital properties of the Galactic nuclear star cluster within 0.5 pc. A black hole merger results in a gravitational wave recoil kick, which causes the surrounding cluster to form an apse-aligned, eccentric disk. We show that stars near the inner edge of an eccentric disk migrate inward and are driven to high eccentricities and inclinations due to secular torques similar to the eccentric Kozai-Lidov mechanism. In our fiducial model, starting with a thin eccentric disk with $e = 0.3$, the initially unoccupied region within $0.04$ pc is populated with high eccentricity, high inclination S-stars within a few Myr. This dynamical channel would suggest that a black hole of mass $2^{+3}_{-1.2} \times 10^5 \ M_{\odot}$ merged with Sgr A* within the last 10 Myr.
title On the Formation of S-stars from a Recent Massive Black Hole Merger in the Galactic Center
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2410.19881