Author ORCID Identifier
Document Type
Article
Publication Date
3-25-2021
Abstract
We investigate the mass-velocity dispersion relation (MVDR) in 29 galaxy clusters in the HIghest X-ray FLUx Galaxy Cluster Sample (HIFLUGCS). We measure the spatially resolved, line-of-sight velocity dispersion profiles of these clusters, which we find to be mostly flat at large radii, reminiscent of the rotation curves of galaxies. We discover a tight empirical relation between the baryonic mass M bar and the flat velocity dispersion σ of the member galaxies, i.e., MVDR,, with the lognormal intrinsic scatter of 12 -3 +3. The residuals of the MVDR are uncorrelated with other cluster properties like temperature, cluster radius, baryonic mass surface density, and redshift. These characteristics are reminiscent of the MVDR for individual galaxies, albeit at about a ten times larger characteristic acceleration scale. The cluster baryon fraction falls short of the cosmic value, exposing a problem: the discrepancy increases systematically for clusters of lower mass and lower baryonic acceleration.
Keywords
dark matter, galaxy clusters, galaxy groups, intracluster medium, X-ray astronomy
Language
English
Publication Title
Astrophysical Journal
Grant
1911909
Rights
© 2021. The American Astronomical Society. All rights reserved. This content is free to access, download, and share. For all other uses, you must obtain permission to reuse content: https://journals.aas.org/article-charges-and-copyright/#AAS_material
Recommended Citation
Yong Tian et al 2021 . Mass-Velocity Dispersion Relation in HIFLUGCS Galaxy Clusters. ApJ 910 56
Manuscript Version
Final Publisher Version