Major mergers are not significant drivers of star formation or morphological transformation around the epoch of peak cosmic star formation

Abstract

We investigate the contribution of major mergers (mass ratios $>1:5$) to stellar mass growth and morphological transformations around the epoch of peak cosmic star formation ($z\sim 2$). We visually classify a complete sample of massive (M $>$ 10${}^{10}$M${}_{\odot }$) galaxies at this epoch, drawn from the CANDELS survey, into late-type galaxies, major mergers, spheroids and disturbed spheroids which show morphological disturbances. Given recent simulation work, which indicates that recent ($<$0.3-0.4 Gyr) major-merger remnants exhibit clear tidal features in such images, we use the fraction of disturbed spheroids to probe the role of major mergers in driving morphological transformations. The percentage of blue spheroids (i.e. with ongoing star formation) that show morphological disturbances is only 21 $\pm$ 4%, indicating that major mergers are not the dominant mechanism for spheroid creation at $z\sim 2$ - other processes, such as minor mergers or cold accretion are likely to be the main drivers of this process. We also use the rest-frame U-band luminosity as a proxy for star formation to show that only a small fraction of the star formation budget ($\sim$3%) is triggered by major mergers. Taken together, our results show that major mergers are not significant drivers of galaxy evolution at $z\sim 2$.

arXiv comment5 pages, 5 figures, accepted for publication in MNRAS

References in corpus (44)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Stellar population synthesis at the resolution of 2003
• Galactic Stellar and Substellar Initial Mass Function
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• Modeling feedback from stars and black holes in galaxy mergers
• CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey
• CANDELS: The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey - The Hubble Space Telescope Observations, Imaging Data Products and Mosaics
• EAZY: A Fast, Public Photometric Redshift Code
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• Gasdynamics and Starbursts in Major Mergers
• The epochs of early-type galaxy formation as a function of environment
• The Star Formation History of Field Galaxies
• The formation history of elliptical galaxies
• High molecular gas fractions in normal massive star forming galaxies in the young Universe
• Galaxies in a simulated $\Lambda$CDM Universe I: cold mode and hot cores
• The Stellar Population Histories of Local Early-Type Galaxies. I. Population Parameters
• From rings to bulges: evidence for rapid secular galaxy evolution at z~2 from integral field spectroscopy in the SINS survey
• Galaxy Merger Morphologies and Time-Scales from Simulations of Equal-Mass Gas-Rich Disc Mergers
• Star formation rate indicators in the Sloan Digital Sky Survey
• Optical Star-Formation Rate Indicators
• The structures and total (minor + major) merger histories of massive galaxies up to z = 3 in the HST GOODS NICMOS Survey: A possible solution to the size evolution problem
• On Sizes, Kinematics, M/L Gradients, and Light Profiles of Massive Compact Galaxies at z~2
• Early type galaxies have been the predominant morphological class for massive galaxies since only z~1
• The Redshift and Mass Dependence on the Formation of The Hubble Sequence at z>1 from CANDELS/UDS
• The importance of minor-merger-driven star formation and black-hole growth in disk galaxies
• CANDELS Visual Classifications: Scheme, Data Release, and First Results
• The Progenitors of the Compact Early-Type Galaxies at High-Redshift
• High-redshift major mergers weakly enhance star formation
• The Hawk-I UDS and GOODS Survey (HUGS): Survey design and deep K-band number counts
• Deconstructing the Galaxy Stellar Mass Function with UKIDSS and CANDELS: the Impact of Colour, Structure and Environment
• A coincidence of disturbed morphology and blue UV colour: minor-merger driven star formation in early-type galaxies at z~0.6
• Studying the emergence of the red sequence through galaxy clustering: host halo masses at z > 2
• Hiding in plain sight: An abundance of compact massive spheroids in the local Universe
• CANDELS: The correlation between galaxy morphology and star formation activity at z~2
• Central Stellar Mass Deficits in the Bulges of Local Lenticular Galaxies, and the Connection with Compact z ~ 1.5 Galaxies
• GEMS: which galaxies dominate the z~0.7 ultraviolet luminosity density?
• Gas Accretion as a Dominant Formation Mode in Massive Galaxies from the GOODS NICMOS Survey
• Minor vs Major Mergers: The Stellar Mass Growth of Massive Galaxies from z=3 using Number Density Selection Techniques
• The insignificance of major mergers in driving star formation at z~2
• Galaxy merger histories and the role of merging in driving star formation at z>1
• Beyond Spheroids and Discs: Classifications of CANDELS Galaxy Structure at 1.4 < z < 2 via Principal Component Analysis
• Galaxy Formation as a Cosmological Tool. I: The Galaxy Merger History as a Measure of Cosmological Parameters
• Newborn spheroids at high redshift: when and how did the dominant, old stars in today's massive galaxies form?
• The growth of galactic bulges through mergers in LCDM haloes revisited. II. Morphological mix evolution

Cited by in corpus (50)

• Galaxy Zoo DECaLS: Detailed Visual Morphology Measurements from Volunteers and Deep Learning for 314,000 Galaxies
• Age dissection of the Milky Way discs: red giants in the Kepler field
• The role of mergers in driving morphological transformation over cosmic time
• High-redshift major mergers weakly enhance star formation
• The KMOS Deep Survey (KDS) I: dynamical measurements of typical star-forming galaxies at z $\simeq$ 3.5
• Mergers, Starbursts, and Quenching in the Simba Simulation
• Morpheus: A Deep Learning Framework For Pixel-Level Analysis of Astronomical Image Data
• The three phases of galaxy formation
• Major Merging History in CANDELS. I. Evolution of the Incidence of Massive Galaxy-Galaxy Pairs from z=3 to z~0
• Interacting galaxies in the IllustrisTNG simulations -- I: Triggered star formation in a cosmological context
• Interacting galaxies in the IllustrisTNG simulations -- II: Star formation in the post-merger stage
• The cosmic evolution of the spatially-resolved star formation rate and stellar mass of the CALIFA survey
• Preparing for low surface brightness science with the Vera C. Rubin Observatory: characterisation of tidal features from mock images
• The role of mergers and interactions in driving the evolution of dwarf galaxies over cosmic time
• Galaxy pairs in the SDSS - XIII. The connection between enhanced star formation and molecular gas properties in galaxy mergers
• Identification of Low Surface Brightness Tidal Features in Galaxies Using Convolutional Neural Networks
• Star Clusters in Evolving Galaxies
• Normal black holes in bulge-less galaxies: the largely quiescent, merger-free growth of black holes over cosmic time
• A direct measurement of galaxy major and minor merger rates and stellar mass accretion histories at $z<3$ using galaxy pairs in the REFINE survey
• The limited role of galaxy mergers in driving stellar mass growth over cosmic time
• Galaxy Zoo: major galaxy mergers are not a significant quenching pathway
• Galaxy mergers up to z < 2.5 II: AGN incidence of merging galaxies at separations of 3-15 kpc
• Investigating the Effect of Galaxy Interactions on Star Formation at 0.5<z<3.0
• Galaxy mergers up to z<2.5 I : The star formation properties of merging galaxies at separations 3-15 kpc
• The role of the most luminous, obscured AGN in galaxy assembly at z~2
• Massive star cluster formation and evolution in tidal dwarf galaxies
• The spatially resolved star formation history of mergers: A comparative study of the LIRGs IC1623, NGC6090, NGC2623, and Mice
• Extremely massive disc galaxies in the nearby Universe form through gas-rich minor mergers
• Why do extremely massive disc galaxies exist today?
• Identification of tidal features in deep optical galaxy images with Convolutional Neural Networks
• Local analogues of high-redshift star-forming galaxies: integral field spectroscopy of green peas
• DustPedia - the relationships between stars, gas and dust for galaxies residing in different environments
• Frequency of Tidal Features Correlates with Age and Internal Structure of Early-type Galaxies
• The SAMI Galaxy Survey: Using Tidal Streams and Shells to Trace the Dynamical Evolution of Massive Galaxies
• The MOSDEF Survey: No Significant Enhancement in Star Formation or Deficit in Metallicity in Merging Galaxy Pairs at 1.5<=z<=3.5
• Relaxed blue ellipticals: accretion-driven stellar growth is a key evolutionary channel for low mass elliptical galaxies
• CANDELS Meets GSWLC: Evolution of the Relationship Between Morphology and Star Formation Since z = 2
• The MOSDEF Survey: Differences in SFR and Metallicity for Morphologically-Selected Mergers at z~2
• Identifying the progenitors of present-day early-type galaxies in observational surveys: correcting `progenitor bias' using the Horizon-AGN simulation
• Massive spheroids can form in single minor mergers
• The Global Environment of Small Galaxy Systems
• Regulation of star formation by large scale gravito-turbulence
• Cosmic Sands: The Origin of Dusty, Star-forming Galaxies in the Epoch of Reionization
• Real galaxy mergers from galaxy pair catalogs
• Hydrodynamical Simulations of the Triggering of Nuclear Activities by Minor Mergers of Galaxies
• Old and New Major Mergers in the SOSIMPLE galaxy, NGC 7135
• Understanding the Universal Dust Attenuation Scaling Relation of Star-Forming Galaxies
• How the spectral energy distribution and galaxy morphology constrain each other, with application to morphological selection using galaxy colours
• The MOSDEF Survey: A New View of a Remarkable z=1.89 Merger
• Chronos: A NIR spectroscopic survey to target the most important phases of galaxy evolution across cosmic time