EVIDENCE FOR THE RAPID FORMATION OF LOW-MASS EARLY-TYPE GALAXIES IN DENSE ENVIRONMENTS

2015/12/01 by Yiqing Liu, Eric W. Peng, John Blakeslee +6 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Globular cluster #Halo #RADIUS #Star formation #Stars #Stellar, planetary, and galactic studies #Virgo Cluster #Virial theorem #astro-ph.GA

paper · pdf · doi:10.3847/0004-637x/818/2/179

11 pages, 8 figures

arxiv created 2015/12/01 · openalex publication_date 2016/02/18 · arxiv updated 2016/03/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

ABSTRACT We explore the environmental dependence of star formation timescales in low-mass galaxies using the [ α /Fe] abundance ratio as an evolutionary clock. We present integrated [ α /Fe] measurements for 11 low-mass ( ) early-type galaxies (ETGs) with a large range of cluster-centric distance in the Virgo Cluster. We find a gradient in [ α /Fe], where the galaxies closest to the cluster center (the cD galaxy, M87) have the highest values. This trend is driven by galaxies within a projected radius of 0.4 Mpc (0.26 times the virial radius of Virgo A), all of which have super-solar [ α /Fe]. Galaxies in this mass range exhibit a large scatter in the [ α /Fe]– σ diagram, and do not obviously lie on an extension of the relation defined by massive ETGs. In addition, we find a correlation between [ α /Fe] and globular cluster specific frequency ( S N ), suggesting that low-mass ETGs that formed their stars over a short period of time were also efficient at forming massive star clusters. The innermost low-mass ETGs in our sample have [ α /Fe] values comparable to that of M87, implying that environment is the controlling factor for star formation timescales in dense regions. These low-mass galaxies could be the surviving counterparts of the objects that have already been accreted into the halo of M87, and may be the link between present-day low-mass galaxies and the old, metal-poor, high-[ α /Fe], high- S N stellar populations seen in the outer halos of massive ETGs.

Citations

• The ACS Virgo Cluster Survey. VI. Isophotal Analysis and the Structure of Early‐Type Galaxies
• Implications for the formation of star clusters from extragalactic star formation rates
• Stellar population models of Lick indices with variable element abundance ratios
• Morphological evolution of discs in clusters
• Population Synthesis in the Blue. IV. Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations
• Virgo Cluster Early-Type Dwarf Galaxies with the Sloan Digital Sky Survey. I. On the Possible Disk Nature of Bright Early-Type Dwarfs
• A NEAR-INFRARED CENSUS OF THE MULTICOMPONENT STELLAR STRUCTURE OF EARLY-TYPE DWARF GALAXIES IN THE VIRGO CLUSTER
• The relation between stellar populations, structure and environment for dwarf elliptical galaxies from the MAGPOP-ITP
• Compositions of halo clusters and the formation of the galactic halo
• Globular Clusters in Dense Clusters of Galaxies
• The ACS Virgo Cluster Survey. XII. The Luminosity Function of Globular Clusters in Early‐Type Galaxies
• HSTPhotometry of Dwarf Elliptical Galaxies in Coma, and an Explanation for the Alleged Structural Dichotomy between Dwarf and Bright Elliptical Galaxies
• The ACS Virgo Cluster Survey. XV. The Formation Efficiencies of Globular Clusters in Early‐Type Galaxies: The Effects of Mass and Environment
• The ACS Virgo Cluster Survey. XIII. SBF Distance Catalog and the Three‐dimensional Structure of the Virgo Cluster
• Nearby early-type galaxies with ionized gas

Cited by

• THE INFLUENCE OF ENVIRONMENT ON THE CHEMICAL EVOLUTION IN LOW-MASS GALAXIES
• The MASSIVE Survey. XII. Connecting Stellar Populations of Early-type Galaxies to Kinematics and Environment