Next Generation Virgo Cluster Survey (NGVS). XXXII:~Search for a Globular Cluster Substructure in the Virgo Galaxy Cluster Core

Abstract

Substructure in globular cluster (GC) populations around large galaxies is expected in galaxy formation scenarios that involve accretion or merger events, and it has been searched for using direct associations between GCs and structure in the diffuse galaxy light, or with GC kinematics. Here, we present a search for candidate substructures in the GC population around the Virgo cD galaxy M87 through the analysis of the spatial distribution of the GC colors.~The study is based on a sample of $\sim 1800$ bright GCs with high-quality $u,g,r,i,z,K_s$ photometry, selected to ensure a low contamination by foreground stars or background galaxies.~The spectral energy distributions of the GCs are associated with formal estimates of age and metallicity, which are representative of its position in a 4-D color-space relative to standard single stellar population models.~Dividing the sample into broad bins based on the relative formal ages, we observe inhomogeneities which reveal signatures of GC substructures.~The most significant of these is a spatial overdensity of GCs with relatively young age labels, of diameter $\sim 0.1$\,deg ($\sim 30$kpc), located to the south of M87.~The significance of this detection is larger than about 5$\sigma$ after accounting for estimates of random and systematic errors.~Surprisingly, no large Virgo galaxy is present in this area, that could potentially host these GCs.~But candidate substructures in the M87 halo with equally elusive hosts have been described based on kinematic studies in the past.~The number of GC spectra available around M87 is currently insufficient to clarify the nature of the new candidate substructure.

arXiv comment11 pages, 6 figures, Accepted for publication in ApJ

References in corpus (45)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Stellar population synthesis at the resolution of 2003
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Evolutionary tracks and isochrones for low- and intermediate-mass stars: from 0.15 to 7 M_sun, and from Z=0.0004 to 0.03
• Evolutionary population synthesis: models, analysis of the ingredients and application to high-z galaxies
• The propagation of uncertainties in stellar population synthesis modeling I: The relevance of uncertain aspects of stellar evolution and the IMF to the derived physical properties of galaxies
• MILES: A Medium resolution INT Library of Empirical Spectra
• Evolution of asymptotic giant branch stars II. Optical to far-infrared isochrones with improved TP-AGB models
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• A standard stellar library for evolutionary synthesis: I. Calibration of theoretical spectra
• Improving PARSEC models for very low mass stars
• PARSEC evolutionary tracks of massive stars up to $350M_{\odot }$ at metallicities 0.0001$\le Z\le$0.04
• A standard stellar library for evolutionary synthesis: II. The M dwarf extension
• New PARSEC evolutionary tracks of massive stars at low metallicity: testing canonical stellar evolution in nearby star forming dwarf galaxies
• STELIB: a library of stellar spectra at R~2000
• Evolution of asymptotic giant branch stars I. Updated synthetic TP-AGB models and their basic calibration
• The Formation of Giant Elliptical Galaxies and Their Globular Cluster Systems
• Stellar population models at high spectral resolution
• MIUSCAT: extended MILES spectral coverage. I. Stellar populations synthesis models
• A standard stellar library for evolutionary synthesis. III. Metallicity calibration
• On the Formation of Globular Cluster Systems in a Hierarchical Universe
• Wide-Field Precision Kinematics of the M87 Globular Cluster System
• The Next Generation Virgo Cluster Survey. VIII. The Spatial Distribution of Globular Clusters in the Virgo Cluster
• A Large Stellar Evolution Database for Population Synthesis Studies. III. Inclusion of the full Asymptotic Giant Branch phase and Web tools for stellar population analyses
• Diffuse Tidal Structures in the Halos of Virgo Ellipticals
• The ongoing assembly of a central cluster galaxy: Phase-space substructures in the halo of M87
• Stellar population models in the UV: I. Characterisation of the New Generation Stellar Library
• Optical Colors of Intracluster Light in the Virgo Cluster Core
• The Next Generation Virgo Cluster Survey - Infrared (NGVS-IR): I. A new Near-UV/Optical/Near-IR Globular Cluster selection tool
• Galactic Globular Clusters as a test for Very Low-Mass stellar models
• The build-up of the cD halo of M87 - evidence for accretion in the last Gyr
• The Next Generation Virgo Cluster Survey (NGVS). XIII. The Luminosity and Mass Function of Galaxies in the Core of the Virgo Cluster and the Contribution from Disrupted Satellites
• MIUSCAT: extended MILES spectral coverage. II. Constraints from optical photometry
• The globular cluster system of the Milky Way: accretion in a cosmological context
• The effect of diffusion on the Red Giant luminosity function 'bump'
• The role of galaxy mergers on the evolution of star clusters
• Specific Frequencies and Luminosity Profiles of Cluster Galaxies and Intracluster Light in Abell 1689
• The Next Generation Virgo cluster Survey (NGVS). XXV. Fiducial panchromatic colors of Virgo core globular clusters and their comparison to model predictions
• Globular Clusters As Tracers of Fine Structure in the Dramatic Shell Galaxy NGC 474
• New Constraints on a complex relation between globular cluster colors and environment
• The Next Generation Virgo cluster Survey (NGVS). XXVI. The issues of photometric age and metallicity estimates for globular clusters
• The Next Generation Virgo Cluster Survey. XIX. Tomography of Milky Way Substructures in the NGVS Footprint
• Main Sequence Star Populations in the Virgo Overdensity Region
• Merger Induced Globular Cluster Formation and Galaxy Evolution

Cited by in corpus (7)

• Fossil stellar streams and their globular cluster populations in the E-MOSAICS simulations
• The Next Generation Virgo Cluster Survey (NGVS) XXXI. The kinematics of intra-cluster globular clusters in the core of the Virgo cluster
• A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE).V. Properties of the ionised gas filament of M87
• The Next Generation Virgo Cluster Survey. XXXIII. Stellar Population Gradients in the Virgo Cluster Core Globular Cluster System
• Substructure in the Globular Cluster Populations of the Virgo Cluster Elliptical Galaxies M84 and M86
• The Color Gradients of the Globular Cluster Systems in M87 and M49
• Isophotal signatures of the brightest cluster galaxy - intracluster light transition