Globular cluster systems of six shell galaxies

Abstract

Shells in Elliptical Galaxies are faint, sharp-edged features, believed to provide evidence of a recent ($\sim 0.5-2\times 10^9$ years ago) merger event. We analyse the Globular Cluster (GC) systems of six shell elliptical galaxies, to examine the effects of mergers upon the GC formation history. We examine the colour distributions, and investigate differences between red and blue globular cluster populations. We present luminosity functions, spatial distributions and specific frequencies ($S_N$) at 50 kpc radius for our sample. We present V and I magnitudes for cluster candidates measured with the HST Advanced Camera for Surveys (ACS). Galaxy background light is modelled and removed, and magnitudes are measured in 8 pixel (0.4 arcsec) diameter apertures. Background contamination is removed using counts from HDFS. We find that the colour distributions for NGC 3923 and NGC 5982 have a bimodal form typical of bright ellipticals, with peaks near $V-I=0.92\pm 0.04$ and $V-I=1.18\pm 0.06$. In NGC 7626, we find in addition a population of abnormally luminous clusters at $M_I=-12.5$. In NGC 2865 we find an unusually blue population, which may also be young. In NGC1344 and NGC474 the red cluster population is marginally detected. The radial surface density profiles are more flattened than the galaxy light in the cores. As already known, in NGC3923, which has a high $S_N$ of 5.6, the radial density distribution is more shallower than the diffuse galaxy light. The clusters in NGC 2865 and NGC 7626 provide evidence for formation of a population associated with a recent merger. In the other galaxies, the properties of the clusters are similar to those observed in other, non-shell, elliptical galaxies.

17 pages, 12 figures, accepted and to be published in A&A

References in corpus (48)

• Cosmic-Ray Rejection by Laplacian Edge Detection
• The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances
• The Photometric Performance and Calibration of the HST Advanced Camera For Surveys
• The Luminosity Function of Young Star Clusters In "The Antennae" Galaxies (NGC 4038/4039)
• The SAURON project - III. Integral-field absorption-line kinematics of 48 elliptical and lenticular galaxies
• Dynamical Evolution of the Mass Function of Globular Star Clusters
• New Insights from HST Studies of Globular Cluster Systems I: Colors, Distances and Specific Frequencies of 28 Elliptical Galaxies
• A Catalogue and Analysis of X-ray luminosities of Early-type galaxies
• On the Formation of Globular Cluster Systems in a Hierarchical Universe
• Globular Cluster Systems I: V-I Color Distributions
• The Globular Cluster System of NGC 1399. I. A Wide-field Photometric Study
• Explaining the Color Distributions of Globular Cluster Systems in Elliptical Galaxies
• The Fundamental Plane at z=1.27: First Calibration of the Mass Scale of Red Galaxies at Redshifts z>1
• The Globular Cluster Systems of the Early-type Galaxies NGC3379, NGC4406, and NGC4594 and Implications for Galaxy Formation
• Stellar Populations and Kinematics of Red Galaxies at z>2: Implications for the Formation of Massive Galaxies
• A photometric and spectroscopic study of dwarf and giant galaxies in the Coma cluster -- III. Spectral ages and metallicities
• Scaling Mass Profiles around Elliptical Galaxies Observed with Chandra and XMM-Newton
• Early-type galaxies in low-density environments
• Kinematics, ages, and metallicities of star clusters in NGC 1316: A 3 Gyr old merger remnant
• Extragalactic Globular Clusters: Old Spectroscopic Ages and New Views on Their Formation
• The Optical and Near-Infrared Morphologies of Isolated Early Type Galaxies
• The Globular Cluster System in the Outer Regions of NGC 4472
• The star cluster system of the 3 Gyr old merger remnant NGC 1316: Clues from optical and near-infrared photometry
• The Age Difference between the Globular Cluster Sub-populations in NGC 4472
• New Insights from HST Studies of Globular Cluster Systems II: Analysis of 29 S0 Systems
• The Connection between Globular Cluster Systems and the Host Galaxies
• The Photometric Properties of Isolated Early-Type Galaxies
• The Ages and Abundances of a Sample of Globular Clusters in M49 (NGC 4472)
• Group, field and isolated early-type galaxies II. Global trends from nuclear data
• A wide-field photometric study of the globular cluster system of NGC 4636
• Metal-Poor Globular Clusters and Galaxy Formation
• Deep Luminosity Functions of Old and Intermediate-Age Globular Clusters in NGC 1316: Evidence for Dynamical Evolution of Second-Generation Globular Clusters
• VLT Spectroscopy of Globular Cluster Systems, I. The Photometric and Spectroscopic Dataset
• Age Estimates for Globular Clusters in NGC 1399
• The Globular Cluster Luminosity Function: New Progress in Understanding an Old Distance Indicator
• The Globular Cluster System of the Canis Major Dwarf Galaxy
• The Luminosity Functions of Old and Intermediate-Age Globular Clusters in NGC 3610
• Spatially resolved stellar populations in the isolated elliptical NGC 821
• Gemini/GMOS Imaging of Globular Clusters in the Virgo Galaxy NGC 4649 (M60)
• The Low Surface Brightness Extent of the Fornax Cluster
• Imaging of the protoelliptical NGC 1700 and its globular cluster system
• Planetary nebulae and stellar kinematics in the flattened elliptical galaxy NGC 1344
• Keck Imaging of the Globular Cluster Systems in the Early--type Galaxies NGC 1052 and NGC 7332
• The Globular Cluster Systems in the Coma Ellipticals. II: Metallicity Distribution and Radial Structure in NGC 4874, and Implications for Galaxy Formation
• A Search for HI in Five Ellipticals with Fine Structure
• Evolution of globular cluster systems in three galaxies of the Fornax cluster
• Infrared Photometry of the Globular Cluster Palomar 6
• Secondary Globular Cluster Populations

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• The Ubiquity and Dual Nature of Ultra Compact Dwarfs
• Gemini/GMOS Imaging of Globular Cluster Systems in Five Early-type Galaxies
• Dependence of the LMXB population on stellar age
• The SLUGGS Survey: The mass distribution in early-type galaxies within five effective radii and beyond
• Dynamical Evolution of Globular Cluster Systems formed in Galaxy Mergers: Deep HST/ACS Imaging of Old and Intermediate-Age Globular Clusters in NGC 3610
• Gemini/GMOS Spectroscopy of the Spheroid and Globular Cluster System of NGC 3923
• HST/ACS observations of shell galaxies: inner shells, shell colours and dust
• Surface Brightness Fluctuations from archival ACS images: a stellar population and distance study
• The Globular Cluster Kinematics and Galaxy Dark Matter Content of NGC 3923
• Globular Cluster System erosion in elliptical galaxies
• The globular cluster system of NGC1316. I. Wide-field photometry in the Washington system
• Isolated ellipticals and their globular cluster systems III. NGC 2271, NGC 2865, NGC 3962, NGC 4240 and IC 4889
• Deep imaging of the shell elliptical galaxy NGC3923 with MegaCam
• Globular Clusters As Tracers of Fine Structure in the Dramatic Shell Galaxy NGC 474
• The globular cluster system in NGC5866: optical observations from HST Advanced Camera for Surveys
• Dissolved Massive Metal-Rich Globular Clusters Can Cause the Range of UV Upturn Strengths Found among Early-type Galaxies
• The merger remnant NGC 3610 and its globular cluster system: a large-scale study
• LMXB populations in galaxy outskirts: globular clusters and supernova kicks
• Intermediate-age Globular Clusters in Four Galaxy Merger Remnants
• Further Definition of the Mass-Metallicity Relation in Globular Cluster Systems Around Brightest Cluster Galaxies
• Revealing the formation mechanism of the shell galaxy NGC474 with MUSE
• Property of Young Massive Clusters in a Galaxy-Galaxy Merger Remnant
• Evidence for Three Subpopulations of Globular Clusters in the Early-Type Post-Starburst Shell Galaxy AM 0139-655
• Spatial Structures in the Globular Cluster Distribution of Fornax Cluster Galaxies
• Star formation in low density HI gas around the Elliptical Galaxy NGC2865