Remnants of recent mergers in nearby early-type galaxies and their classification

Abstract

We search for signatures of recent galaxy close interactions and mergers in a sample of 202 early-type galaxies in the local universe from the public SDSS Stripe82 deep images (${\mu }_r\sim 28.5$ mag arcsec${}^{-2}$). Using two different methods to remove galaxies' smooth and symmetric light distribution, we identify and characterize eleven distinct types of merger remnants embedded in the diffuse light of these early-type galaxies. We discuss how the morphology of merger remnants can result from different kinds of minor and major mergers, and estimate the fraction of early-type galaxies in the local universe with evidence of recent major (27%) and minor (57%) mergers. The merger fractions deduced are higher than in several earlier surveys. Among remnants, we find that shells are the dominant merger debris (54%) associated with early-type galaxies, resulting from both major and minor mergers, with those characteristics of major mergers being significant (24% of shell host galaxies). The most uncommon merger-related structures are boxy isophotes of the stellar distribution and the presence of disk fragments near the cores of galaxies. We develop a classification scheme for these fine structures that may be used to infer their likely genesis histories. The classification is primarily based on the mass ratios of the merged galaxies. This work, when combined with predictions from numerical simulations, indicates that most (if not all) early-type galaxies in the local Universe are continually evolving as a result of (minor) merger activities.

Accepted for publication in MNRAS [with 9 Figures, 3 Tables]

References in corpus (35)

• Overview of the SDSS-IV MaNGA Survey: Mapping Nearby Galaxies at Apache Point Observatory
• Galaxy Merger Morphologies and Time-Scales from Simulations of Equal-Mass Gas-Rich Disc Mergers
• Tracing Galaxy Formation with Stellar Halos II: Relating Substructure in Phase- and Abundance-Space to Accretion Histories
• The Atlas3D project -- XXIX. The new look of early-type galaxies and surrounding fields disclosed by extremely deep optical images
• A Classical Morphological Analysis of Galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S4G)
• Multiple minor mergers: formation of elliptical galaxies and constraints for the growth of spiral disks
• A Catalogue of Morphologically Classified Galaxies from the Sloan Digital Sky Survey: North Equatorial Region
• The Millennium Galaxy Catalogue: The connection between close pairs and asymmetry; implications for the galaxy merger rate
• The Luminosity Dependence of the Galaxy Merger Rate
• Peanuts, brezels and bananas: food for thought on the orbital structure of the Galactic bulge
• Probing the merger history of red early-type galaxies with their faint stellar substructures
• On the lifetime of merger features of equal-mass disk mergers
• A Comparison of Galaxy Merger History Observations and Predictions from Semi-Analytic Models
• Atlas and Catalog of Collisional Ring Galaxies
• Tidal debris in elliptical galaxies as tracers of mergers with disks
• Enhanced mergers of galaxies in low-redshift clusters
• Characterization of Low Surface Brightness structures in annotated deep images
• The diverse nature and formation paths of slow rotator galaxies in the EAGLE simulations
• Galactic Rings Revisited. I. CVRHS Classifications of 3962 Ringed Galaxies from the Galaxy Zoo 2 Database
• Morphology and enhanced star formation in a Cartwheel-like ring galaxy
• A Recent Major Merger Tale for the Closest Giant Elliptical Galaxy Centaurus A
• Young stellar populations in early-type galaxies in the Sloan Digital Sky Survey
• The Complex North Transition Region of Centaurus A: A Galactic Wind
• A large sample of Kohonen selected E+A (post-starburst) galaxies from the Sloan Digital Sky Survey
• NGC 741 - Mergers and AGN feedback on galaxy group scale
• Modelling X-shaped Radio Galaxies: Dynamical and Emission Signatures from the Back-flow model
• A giant umbrella-like stellar stream around the tidal ring galaxy NGC 922
• Long Tidal Tails in Merging Galaxies and Their Implications
• Dynamical Modelling and Emission Signatures of a Candidate Dual AGN with Precessing Radio Jets
• Galaxies with Shells in the Illustris Simulation: Metallicity Signatures
• External gas accretion provides a fresh gas supply to the active S0 galaxy NGC 5077
• Morphology and surface photometry of a sample of isolated early-type galaxies from deep imaging
• MOND prediction of a new giant shell in the elliptical galaxy NGC3923
• Ubiquitous signs of interactions in early-type galaxies with prolate rotation
• Discovery of a near-infrared bar and a pseudobulge in the collisional ring galaxy Cartwheel

Cited by in corpus (8)

• Constraining the Gravitational Potential from the Projected Morphology of Extragalactic Tidal Streams
• Extragalactic Stellar Tidal Streams in the Dark Energy Survey
• Extragalactic Stellar Tidal Streams: Observations meet Simulation
• 3D spectroscopy with GTC-MEGARA of the triple AGN candidate in SDSS J102700.40+174900.8
• STRRINGS: STReams in Residual Images of Nearby GalaxieS
• Kinematics of the lens host S0 galaxy NGC 1553: role of secular processes
• HI gas in the rejuvenated radio galaxy PKS 2014-55
• Stellar Abundances at the Center of Early Type Galaxies with Fine Structure