2016/08/24 by Mia Sauda Bovill, Thomas H. Puzia, Massimo Ricotti +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Baryonic dark matter #Centaurus A #Dark galaxy #Dark matter #Dark matter halo #Dwarf galaxy #Dwarf galaxy problem #Galaxies: Formation, Evolution, Phenomena #Galaxy #Globular cluster #Stellar, planetary, and galactic studies #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.3847/0004-637x/832/1/88
11 pages, 10 figure, 1 table. Accepted to ApJ
arxiv created 2016/08/24 · openalex created_date 2016/09/16 · openalex publication_date 2016/11/18 · arxiv updated 2016/12/07 · openalex updated_date 2026/08/05
ABSTRACT We present theoretical constraints for the formation of the newly discovered dark star clusters (DSCs) with high mass-to-light ( <?CDATA \mathcal M / \mathcal L ?> ) ratios, from Taylor et al. These compact stellar systems photometrically resemble globular clusters (GCs) but have dynamical <?CDATA \mathcal M / \mathcal L ?> ratios of ∼10–100, closer to the expectations for dwarf galaxies. The baryonic properties of the DSCs suggest that their host dark matter halos likely virialized at high redshift with <?CDATA \mathcal M \gt 108M\odot ?> . We use a new set of high-resolution N -body simulations of Centaurus A to determine whether there is a set of z = 0 subhalos whose properties are in line with these observations. While we find such a set of subhalos, when we extrapolate the dark matter density profiles into the inner 20 pc, no dark matter halo associated with Centaurus A in our simulations, at any redshift, can replicate the extremely high central mass densities of the DSCs. Among the most likely options for explaining 10 5 – <?CDATA 107M\odot ?> within subhalos of 10 pc diameter is the presence of a central massive black hole (BH). We therefore propose that the DSCs are remnant cusps of stellar systems surrounding the central BHs of dwarf galaxies that have been almost completely destroyed by interactions with Centaurus A.