2022MNRAS.511.4251E -
Mon. Not. R. Astron. Soc., 511, 4251-4264 (2022/April-2)
Dark and luminous mass components of Omega Centauri from stellar kinematics.
EVANS A.J., STRIGARI L.E. and ZIVICK P.
Abstract (from CDS):
We combine proper motion data from Gaia EDR3 and HST with line-of-sight velocity data to study the stellar kinematics of the ω Cen globular cluster. Using a steady-state, axisymmetric dynamical model, we measure the distribution of both the dark and luminous mass components. Assuming both Gaussian and Navarro-Frenk-White mass profiles, depending on the data set, we measure an integrated mass of <=106 M☉ within the ω Cen half-light radius for a dark component that is distinct from the luminous stellar component. For the HST and radial velocity data, models with a non-luminous mass component are strongly statistically preferred relative to a stellar mass-only model with a constant mass-to-light ratio. While a compact core of stellar remnants may account for a dynamical mass up to ∼5 x 105 M☉, they likely cannot explain the higher end of the range. This leaves open the possibility that this non-luminous dynamical mass component comprises non-baryonic dark matter. In comparison to the dark matter distributions around dwarf spheroidal galaxies, the ω Cen dark mass component is much more centrally concentrated. Interpreting the non-luminous mass distribution as particle dark matter, we use these results to obtain the J-factor, which sets the sensitivity to the annihilation cross-section. For the data sets considered, the range of median J-factors is ∼1022-1024 GeV2 cm–5, which is larger than that obtained for any dwarf spheroidal galaxy.
Abstract Copyright:
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society
Journal keyword(s):
Galaxy: globular clusters - galaxies: kinematics and dynamics - cosmology: dark matter
Simbad objects:
2
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2022MNRAS.511.4251E and select 'bookmark this link' or equivalent in the popup menu