| Full text | |
| Author(s): |
Limberg, Guilherme
Total Authors: 1
|
| Document type: | Journal article |
| Source: | Astrophysical Journal Letters; v. 977, n. 1, p. 7-pg., 2024-12-10. |
| Abstract | |
The discovery of fast moving stars in Milky Way's most massive globular cluster, omega Centauri (omega Cen), has provided strong evidence for an intermediate-mass black hole (IMBH). However, omega Cen is known to be the stripped nuclear star cluster (NSC) of an ancient, now-destroyed, dwarf galaxy. The best candidate to be the original host progenitor of omega Cen is the tidally disrupted dwarf Gaia-Sausage/Enceladus (GSE), a former Milky Way satellite as massive as the Large Magellanic Cloud. I compare omega Cen/GSE with other central BH hosts and place it within the broader context of BH-galaxy (co)evolution. The IMBH of omega Cen/GSE follows the scaling relation between central BH mass and host stellar mass (M-BH-M-star) extrapolated from local massive galaxies (M-star greater than or similar to 10(10) M-circle dot). Therefore, the IMBH of omega Cen/GSE suggests that this relation extends to the dwarf-galaxy regime. I verify that omega Cen (GSE), as well as other NSCs with candidate IMBHs and ultracompact galaxies also follow the M-BH-sigma(star) relation with stellar velocity dispersion. Under the assumption of direct collapse BH, omega Cen/GSE's IMBH would require a low initial mass (less than or similar to 10,000 M-circle dot) and almost no accretion over similar to 3 Gyr, which could be the extreme opposite of high-z galaxies with overmassive BHs such as GN-z11. If omega Cen/GSE's IMBH formed from a Population III supernova remnant, then it could indicate that both light and heavy seeding mechanisms of central BH formation are at play. Other stripped NSCs and dwarf galaxies could help further populate the M-BH-M-star and M-BH-sigma(star) relations in the low-mass regime and constrain IMBH demographics and their formation channels. (AU) | |
| FAPESP's process: | 21/10429-0 - The chemodynamical structure of the ancient galactic halo |
| Grantee: | Guilherme Limberg |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |