Examining Baryonic Faber-Jackson Relation in Galaxy Groups

Fuente: arXiv
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Autores principales: Sadhu, Pradyumna, Tian, Yong
Formato: Preprint
Publicado: 2024
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author Sadhu, Pradyumna
Tian, Yong
author_facet Sadhu, Pradyumna
Tian, Yong
contents We investigate the Baryonic Faber-Jackson Relation (BFJR), examining the correlation between baryonic mass and velocity dispersion in galaxy groups and clusters. Originally analysed in elliptical galaxies, the BFJR is derivable from the empirical Radial Acceleration Relation (RAR) and MOdified Newtonian Dynamics (MOND), both showcasing a characteristic acceleration scale $g_\mathrm{\dagger}=1.2\times10^{-10}\,\mathrm{m}\,\mathrm{s}^{-2}$. Recent interpretations within MOND suggest that galaxy group dynamics can be explained solely by baryonic mass, hinting at a BFJR with $g_{\dagger}$ in these systems. To explore this BFJR, we combined X-ray and optical measurements for six galaxy clusters and 13 groups, calculating baryonic masses by combining X-ray gas and stellar mass estimates. Simultaneously, we computed spatially resolved velocity dispersion profiles from membership data using the biweight scale in radial bins. Our results indicate that the BFJR in galaxy groups, using total velocity dispersion, aligns with MOND predictions. Conversely, galaxy clusters exhibit a parallel BFJR with a larger acceleration scale. Analysis using tail velocity dispersion in galaxy groups shows a leftward deviation from the BFJR. Additionally, stacked velocity dispersion profiles reveal two distinct types: declining and flat, based on two parallel BFJRs. The declining profile, if not due to the anisotropy parameters or the incomplete membership, suggests a deviation from standard dark matter density profiles. We further identify three galaxy groups with unusually low dark matter fractions.
format Preprint
id arxiv_https___arxiv_org_abs_2402_13320
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Examining Baryonic Faber-Jackson Relation in Galaxy Groups
Sadhu, Pradyumna
Tian, Yong
Cosmology and Nongalactic Astrophysics
Astrophysics of Galaxies
We investigate the Baryonic Faber-Jackson Relation (BFJR), examining the correlation between baryonic mass and velocity dispersion in galaxy groups and clusters. Originally analysed in elliptical galaxies, the BFJR is derivable from the empirical Radial Acceleration Relation (RAR) and MOdified Newtonian Dynamics (MOND), both showcasing a characteristic acceleration scale $g_\mathrm{\dagger}=1.2\times10^{-10}\,\mathrm{m}\,\mathrm{s}^{-2}$. Recent interpretations within MOND suggest that galaxy group dynamics can be explained solely by baryonic mass, hinting at a BFJR with $g_{\dagger}$ in these systems. To explore this BFJR, we combined X-ray and optical measurements for six galaxy clusters and 13 groups, calculating baryonic masses by combining X-ray gas and stellar mass estimates. Simultaneously, we computed spatially resolved velocity dispersion profiles from membership data using the biweight scale in radial bins. Our results indicate that the BFJR in galaxy groups, using total velocity dispersion, aligns with MOND predictions. Conversely, galaxy clusters exhibit a parallel BFJR with a larger acceleration scale. Analysis using tail velocity dispersion in galaxy groups shows a leftward deviation from the BFJR. Additionally, stacked velocity dispersion profiles reveal two distinct types: declining and flat, based on two parallel BFJRs. The declining profile, if not due to the anisotropy parameters or the incomplete membership, suggests a deviation from standard dark matter density profiles. We further identify three galaxy groups with unusually low dark matter fractions.
title Examining Baryonic Faber-Jackson Relation in Galaxy Groups
topic Cosmology and Nongalactic Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2402.13320