The Baryonic Halos of Isolated Elliptical Galaxies

• Main Authors: Ricardo Salinas, Adebusola Alabi, Nicklas Hammar, Tom Richtler, Richard R. Lane, Mischa Schirmer
• Format: Article
• Language: English
• Published: MDPI AG 2017-08-01
• Series: Galaxies
• Subjects: galaxies: star clusters: general; galaxies: halos; galaxies: elliptical and lenticular; CD
• Online Access: https://www.mdpi.com/2075-4434/5/3/42

Without the interference of a number of events, galaxies may suffer in crowded environments (e.g., stripping, harassment, strangulation); isolated elliptical galaxies provide a control sample for the study of galaxy formation. We present the study of a sample of isolated ellipticals using imaging from a variety of telescopes, focusing on their globular cluster systems as tracers of their stellar halos. Our main findings are: (a) GC color bimodality is common even in the most isolated systems; (b) the specific frequency of GCs is fairly constant with galaxy mass, without showing an increase towards high-mass systems like in the case of cluster ellipticals; (c) on the other hand, the red fraction of GCs follows the same inverted V shape trend with mass as seen in cluster ellipticals; and (d) the stellar halos show low Sérsic indices which are consistent with a major merger origin.