Stellar population and the origin of intra-cluster stars around brightest cluster galaxies: the case of NGC 3311

Abstract

Context. We investigate the stellar population and the origin of diffuse light around brightest cluster galaxies. Aims. We study the stellar population of the dynamically hot stellar halo of NGC 3311, the brightest galaxy in the Hydra I cluster, and that of photometric substructures in the diffuse light to constrain the origin of these components. Methods. We analyze absorption lines in medium-resolution, long-slit spectra in the wavelength range 4800-5800 angstrom obtained with FORS2 at the Very Large Telescope. We measure the equivalent width of Lick indices out to 20 kpc from the center of NGC 3311 and fit them with stellar population models that account for the [alpha/Fe] overabundance. Results. Stars in the dynamically hot halo of NGC 3311 are old (age > 13 Gyr), metal-poor ([Z/H] ~ -0.35), and alpha-enhanced ([alpha/Fe] ~ 0.48). Together with the high velocity dispersion, these measurements indicate that the stars in the halo were accreted from the outskirts of other early-type galaxies, with a possible contribution from dwarf galaxies. We identify a region in the halo of NGC 3311 associated with a photometric substructure where the stellar population is even more metal-poor ([Z/H] ~ -0.73). In this region, our measurements are consistent with a composite stellar population superposed along the line of sight, consisting of stars from the dynamically hot halo of NGC 3311 and stars stripped from dwarf galaxies. The latter component contributes < 28% to the local surface brightness. Conclusions. The build-up of diffuse light around NGC 3311 is on-going. Based on the observed stellar population properties, the dominant part of these stars may have come from the outskirts of bright early-type galaxies, while stars from stripped dwarf galaxies are presently being added.

8 pages, 4 figures. Accepted for publication in Astronomy & Astrophysics

References in corpus (24)

• The hierarchical formation of the brightest cluster galaxies
• The Two Phases of Galaxy Formation
• The Importance of Mergers for the Origin of Intracluster Stars in Cosmological Simulations of Galaxy Clusters
• A method to remove residual OH emission from near infrared spectra
• Flux-calibrated stellar population models of Lick absorption-line indices with variable element abundance ratios
• Dissecting the size evolution of elliptical galaxies since z~1: puffing up vs minor merging scenarios
• The Formation and Evolution of Intracluster Light
• On the interpretation of age and chemical composition of composite stellar populations determined with line-strength indices
• The stellar population histories of early-type galaxies. III. The Coma Cluster
• The Fossil Record of Two-phase Galaxy Assembly: Kinematics and Metallicities in the Nearest S0 Galaxy
• Evidence for Two Phases of Galaxy Formation from Radial Trends in the Globular Cluster System of NGC 1407
• The Metallicity Distribution of Intracluster Stars in Virgo
• The relation between stellar populations, structure and environment for dwarf elliptical galaxies from the MAGPOP-ITP
• The Stellar Populations of Stripped Spiral Galaxies in the Virgo Cluster
• The early-type dwarf galaxy population of the Hydra I cluster
• Spatially resolved kinematics and stellar populations of brightest cluster and group galaxies
• The Kinematics of Intracluster Planetary Nebulae and the On-Going Subcluster Merger in the Coma Cluster Core
• Dating the formation of the counter-rotating stellar disc in the spiral galaxy NGC 5719 by disentangling its stellar populations
• Stellar Populations of Bulges in 14 Cluster Disc Galaxies
• Radial kinematics of brightest cluster galaxies
• The unmixed kinematics and origins of diffuse stellar light in the core of the Hydra I cluster (Abell 1060)
• The early-type galaxies NGC 1407 and NGC 1400 - II: star formation and chemical evolutionary history
• Line strengths of early-type galaxies
• Diffuse Intracluster Light at Intermediate Redshifts: ICL observations in a X-ray cluster at z=0.29

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• The Stellar Halos of Massive Elliptical Galaxies II: Detailed Abundance Ratios at Large Radius
• Intra Cluster Light properties in the CLASH-VLT cluster MACS J1206.2-0847
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• A tale of two tails and an off-centered envelope: diffuse light around the cD galaxy NGC 3311 in the Hydra I cluster
• The Fornax Deep Survey with VST. VIII. Connecting the accretion history with the cluster density
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• The Fornax3D project: Tracing the assembly history of the cluster from the kinematic and line-strength maps
• The first detection of ultra-diffuse galaxies in the Hydra I cluster from VEGAS survey
• Theoretical Predictions of Colors and Metallicity of the Intra-Cluster Light
• The MASSIVE Survey - XII Connecting Stellar Populations of Early-Type Galaxies to Kinematics and Environment
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• A Detection of the Environmental Dependence of the Sizes and Stellar Haloes of Massive Central Galaxies
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• The Fornax3D project: The assembly history of massive early-type galaxies in the Fornax cluster from deep imaging and integral field spectroscopy
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• L-GALAXIES 2020: The formation and chemical evolution of stellar haloes in Milky Way Analogues and galaxy clusters
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