Journal Article

The baryonic haloes of elliptical galaxies: radial distribution of globular clusters and diffuse hot gas

Duncan A. Forbes, Trevor Ponman and Ewan O'Sullivan

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 425, issue 1, pages 66-73
Published in print September 2012 | ISSN: 0035-8711
Published online September 2012 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2012.21368.x
The baryonic haloes of elliptical galaxies: radial distribution of globular clusters and diffuse hot gas

Show Summary Details

Preview

Abstract

For a sample of nine well-studied giant ellipticals, we compare the projected radial distribution of their red and blue globular cluster (GC) subpopulations with their host galaxy stellar and X-ray surface brightness profiles. We support previous findings that the surface density distribution of red (metal-rich) GCs follows that of the host galaxy starlight. We find good agreement between the outer slope of the blue GC surface density and that of the galaxy X-ray emission. This coincidence of projected radial profiles is likely due to the fact that both blue GCs and X-ray emitting hot gas share the same gravitational potential in equilibrium. When deprojected the X-ray emitting hot gas has a radial density dependence that is the square root of that for the GC density. We further show that the energy per unit mass for blue GCs is roughly half that of the hot gas.

Keywords: globular clusters: general; galaxies: formation; galaxies: individual; galaxies: star clusters

Journal Article.  5767 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.