Minor Mergers are not enough: The importance of Major Mergers during Brightest Cluster Galaxy assembly

Abstract

We investigate the roles of major and minor mergers during brightest cluster galaxy (BCG) assembly using surface brightness profiles, line indices, and fundamental plane relations. Based on our own sample and consistently reanalyzed Sloan Digital Sky Survey data, we find that BCGs and luminous normal ellipticals (LNEs) have similar central velocity dispersions, central absorption line strengths, and central surface brightnesses. However, BCGs are more luminous due to their much larger radial extent. These properties result in a flattening of the Faber$-$Jackson and Mg${}_{\mathrm{b}}-$luminosity relations above 10${}^{10.6}$ L${}_{\odot ,g^{\prime }}$. We use this effect to estimate an amount of $60-80$ of accreted and merged light in BCGs relative to LNEs, which agrees with results from cosmological simulations. We determine the contribution of this excess light (EL) at each radius from the difference between the surface flux profiles of BCGs and LNEs. It is small in the center but increases steeply to 50% at $\sim$3 kpc radius. The shape of these profiles suggests that BCGs could be formed from LNEs in three major merger processes. This is also consistent with the mild increase of the Sérsic indices from $n\approx 4$ to $n\approx 6$, as confirmed in merger simulations. We note that minor mergers cannot be the dominant origin of the BCG's EL because they deposit too few stars at intermediate radii $r\lesssim 20$ kpc. The shape of the EL profile also explains a detected offset of 0.14 dex of the fundamental planes for BCGs and LNEs relative to each other.

arXiv comment40 pages, 20 figures, 10 tables. Accepted for publication in ApJS

References in corpus (124)

• The NumPy array: a structure for efficient numerical computation
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Seventh Data Release of the Sloan Digital Sky Survey
• Detailed Structural Decomposition of Galaxy Images
• The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III
• Parametric Recovery of Line-of-Sight Velocity Distributions from Absorption-Line Spectra of Galaxies via Penalized Likelihood
• Detailed Decomposition of Galaxy Images. II. Beyond Axisymmetric Models
• Galaxy Harassment and the Evolution of Clusters of Galaxies
• The hierarchical formation of the brightest cluster galaxies
• The epochs of early-type galaxy formation as a function of environment
• MILES: A Medium resolution INT Library of Empirical Spectra
• The Sixth Data Release of the Sloan Digital Sky Survey
• The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III
• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• A Cosmology Calculator for the World Wide Web
• The SAURON project - IV. The mass-to-light ratio, the virial mass estimator and the fundamental plane of elliptical and lenticular galaxies
• Minor mergers and the size evolution of elliptical galaxies
• Structure and Formation of Elliptical and Spheroidal Galaxies
• The Growth of Massive Galaxies Since z=2
• astroquery: An Astronomical Web-Querying Package in Python
• The Two Phases of Galaxy Formation
• Improved background subtraction for the Sloan Digital Sky Survey images
• The Fundamental Plane for cluster E and S0 galaxies
• Dynamical family properties and dark halo scaling relations of giant elliptical galaxies
• The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars
• Rotation-Dependent Catastrophic Disruption of Gravitational Aggregates
• Dependence of the outer density profiles of halos on their mass accretion rate
• The 1% Concordance Hubble Constant
• Dynamical Friction and Galaxy Merging Timescales
• The Masses of Nuclear Black Holes in Luminous Elliptical Galaxies and Implications for the Space Density of the Most Massive Black Holes
• Early-type galaxies in the SDSS. III. The Fundamental Plane
• How special are Brightest Group and Cluster Galaxies?
• The massive end of the luminosity and stellar mass functions: Dependence on the fit to the light profile
• How do minor mergers promote inside-out growth of ellipticals, transforming the size, density profile and dark matter fraction?
• The Importance of Mergers for the Origin of Intracluster Stars in Cosmological Simulations of Galaxy Clusters
• Analytical approximations of K-corrections in optical and near-infrared bands
• Internal and Collective Properties of Galaxies in the Sloan Digital Sky Survey
• Global Relationships Among the Physical Properties of Stellar Systems
• The luminosities, sizes and velocity dispersions of Brightest Cluster Galaxies: Implications for formation history
• Constraints on galaxy formation from alpha-enhancement in luminous elliptical galaxies
• A catalogue of 2D photometric decompositions in the SDSS-DR7 spectroscopic main galaxy sample: preferred models and systematics
• A universal ultraviolet-optical colour-colour-magnitude relation of galaxies
• On the formation and physical properties of the Intra-Cluster Light in hierarchical galaxy formation models
• Near-IR line-strengths in elliptical galaxies: evidence for IMF variations?
• Curvature in the scaling relations of early-type galaxies
• Near-Infrared Imaging of Early-Type Galaxies III. The Near-Infrared Fundamental Plane
• Relaxation and Stripping: The Evolution of Sizes, Dispersions and Dark Matter Fractions in Major and Minor Mergers of Elliptical Galaxies
• The luminosity and stellar mass Fundamental Plane of early-type galaxies
• Correlations Between Supermassive Black Holes, Velocity Dispersions, and Mass Deficits in Elliptical Galaxies with Cores
• Brightest Cluster Galaxies at the Present Epoch
• Intracluster Light at the Frontier II: The Frontier Fields Clusters
• The Dark Matter Distribution in Abell 383: Evidence for a Shallow Density Cusp from Improved Lensing, Stellar Kinematic and X-ray Data
• The Co-Evolution of Total Density Profiles and Central Dark Matter Fractions in Simulated Early-Type Galaxies
• SDSS-IV DR17: Final Release of MaNGA PyMorph Photometric and Deep Learning Morphological Catalogs
• Kinematic Properties and Stellar Populations of Faint Early-Type Galaxies. I. Velocity Dispersion Measurements of Central Coma Galaxies
• The fundamental plane of EDisCS galaxies - The effect of size evolution
• The 6dF Galaxy Survey: The Near-Infrared Fundamental Plane of Early-Type Galaxies
• The Metallicity Distribution of Intracluster Stars in Virgo
• The Dynamical Fingerprint of Core Scouring in Massive Elliptical Galaxies
• A 40-billion solar mass black hole in the extreme core of Holm 15A, the central galaxy of Abell 85
• Luminosity Dependence in the Fundamental Plane Projections of Elliptical Galaxies
• SDSS-IV MaNGA: Modeling the Spectral Line Spread Function to Sub-Percent Accuracy
• Spectroscopic Determination of the Faint End of the Luminosity Function in the Nearby Galaxy Clusters A2199 and Virgo
• The Cluster Velocity Dispersion of the Abell 2199 cD Halo of NGC 6166
• The puzzlingly small CaII triplet absorption in elliptical galaxies
• Photometric Properties and Scaling Relations of Early Type Brightest Cluster Galaxies
• Structure of Brightest Cluster Galaxies and Intracluster Light
• A tale of two tails and an off-centered envelope: diffuse light around the cD galaxy NGC 3311 in the Hydra I cluster
• 2DPHOT: A Multi-purpose Environment for the Two-dimensional Analysis of Wide-field Images
• The X-Shooter Spectral Library (XSL): Data Release 2
• The MASSIVE Survey - VIII. Stellar Velocity Dispersion Profiles and Environmental Dependence of Early-Type Galaxies
• The Fundamental Plane of Early Type Galaxies in Nearby Clusters from the WINGS Database
• The Fundamental Plane for z=0.8-0.9 cluster galaxies
• Stellar Populations of Elliptical Galaxies in the Local Universe
• SPIDER II - The Fundamental Plane of Early-type Galaxies in grizYJHK
• The Massive End of the Stellar Mass Function
• Stellar atmospheric parameters for 754 spectra from the X-shooter Spectral Library
• Evidence for recent star formation in BCGs: a correspondence between blue cores and UV excess
• The different growth pathways of Brightest Cluster Galaxies and the Intra-Cluster Light
• Photometric dissection of Intracluster Light and its correlations with host cluster properties
• On the origin of the scatter around the Fundamental Plane: correlations with stellar population parameters
• The stellar halos of ETGs in the IllustrisTNG simulations: II. Accretion, merger history, and dark halo connection
• Calibrating the fundamental plane with SDSS DR8 data
• Dual Stellar Halos in the Standard Elliptical Galaxy M105 and Formation of Massive Early-Type Galaxies
• The growth of brightest cluster galaxies in the TNG300 simulation:dissecting the contributions from mergers and in situ star formation
• The Fornax Cluster VLT Spectroscopic Survey II - Planetary Nebulae kinematics within 200 kpc of the cluster core
• Intergalactic stellar populations in intermediate redshift clusters
• LRS2: the new facility low resolution integral field spectrograph for the Hobby-Eberly Telescope
• Stellar Velocity Dispersion: Linking Quiescent Galaxies to their Dark Matter Halos
• Stellar splashback: the edge of the intracluster light
• Discovery of a Possible Splashback Feature in the Intracluster Light of MACS J1149.5+2223
• Sloshing in its cD halo: MUSE kinematics of the central galaxy NGC 3311
• Diversity in the stellar velocity dispersion profiles of a large sample of Brightest Cluster Galaxies $z\le 0.3$
• Abundance ratios in red-sequence galaxies over a wide mass range: The "X-planes" for magnesium, calcium, carbon and nitrogen
• The Kormendy Relation for early-type galaxies. Dependence on the magnitude range
• Diffuse Intracluster Light at Intermediate Redshifts: ICL observations in a X-ray cluster at z=0.29
• Accreted or Not Accreted? The Fraction of Accreted Mass in Galaxies from Simulations and Observations
• Ca, Fe, and Mg Trends Among and Within Elliptical Galaxies
• Toward Understanding the origin of the Fundamental Plane for Early-Type Galaxies
• Early-type galaxies in the Coma cluster: a new piece in the calcium puzzle
• Deep spectroscopy of nearby galaxy clusters: I. Spectroscopic luminosity function of Abell 85
• The dynamically hot stellar halo around NGC 3311: a small cluster-dominated central galaxy
• The Rising Stellar Velocity Dispersion of M87 from Integrated Starlight
• The Fundamental Plane for early-type galaxies. Dependence on the magnitude range
• Comparing PyMorph and SDSS photometry. I. Background sky and model fitting effects
• The UV-upturn in brightest cluster galaxies
• The sigma - L correlation in Nearby Early-Type Galaxies
• The Stellar Mass Fundamental Plane: The virial relation and a very thin plane for slow-rotators
• The Transition Region between Brightest Cluster Galaxies and Intra-Cluster Light in Galaxy Groups and Clusters
• Plain fundamentals of Fundamental Planes: Analytics and algorithms
• Kinematics of the diffuse intragroup and intracluster light in groups and clusters of galaxies in the Local Universe within 100 Mpc distance
• Detection of spatial correlations of fundamental plane residuals, and cosmological implications
• Deep spectroscopy of nearby galaxy clusters: II. The Hercules cluster
• Fundamental Plane of BOSS galaxies: Correlations with galaxy properties, density field and impact on RSD measurements
• MaNGA galaxy properties -- I. An extensive optical, mid-infrared photometric, and environmental catalogue
• Velocity dispersion of the brightest cluster galaxies in cosmological simulations
• The intrinsic dispersion of the Faber-Jackson relation for early-type galaxies as function of the mass and redshift
• YZiCS: On the Mass Segregation of Galaxies in Clusters
• Galaxy And Mass Assembly (GAMA): Defining Passive Galaxy Samples and Searching for the UV Upturn
• The Most Predictive Physical Properties for the Stellar Population Radial Profiles of Nearby Galaxies
• A Trail of the Invisible: Blue Globular Clusters Trace the Radial Density Distribution of the Dark Matter -- Case Study of NGC 4278
• The Fundamental Plane Relation of Early-Type Galaxies: Environmental Dependence
• The Dragonfly Wide Field Survey. II. Accurate Total Luminosities and Colors of Nearby Massive Galaxies and Implications for the Galaxy Stellar Mass Function

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• Euclid: Early Release Observations -- The intracluster light and intracluster globular clusters of the Perseus cluster
• Characterising the intra-cluster light in The Three Hundred simulations
• The supermassive black hole merger driven evolution of high-redshift red nuggets into present-day cored early-type galaxies
• Triaxial Schwarzschild Models of NGC 708: a 10-billion solar mass black hole in a low dispersion galaxy with a Kroupa IMF
• Euclid preparation LXX. Forecasting detection limits for intracluster light in the Euclid Wide Survey
• Major Mergers Mean Major Offset: Drivers of Intrinsic Scatter in The $M_{GCS}-M_h$ Scaling Relation for Massive Elliptical Galaxies
• Star Formation, Nebulae, and Active Galactic Nuclei in CLASH Brightest Cluster Galaxies. I. Dependence on Core Entropy of Intracluster Medium
• Two-phase formation of galaxies: the coevolution between galaxies and dark matter halos
• Is there a tilt in the fundamental (hyper)plane?
• Emergence of the Galaxy Morphology-Star Formation Activity-Clustercentric Radius Relations in Galaxy Clusters
• Time Delay Cosmography: Analysis of Quadruply Lensed QSO SDSSJ1433 from Wendelstein Observatory
• Isophotal signatures of the brightest cluster galaxy - intracluster light transition