Towards a consistent framework of comparing galaxy mergers in observations and simulations

Abstract

Aims. We aim to perform consistent comparisons between observations and simulations on the mass dependence of the galaxy major merger fraction at low redshift over an unprecedentedly wide range of stellar masses (10^9 to 10^12 solar masses). Methods. We first carry out forward modelling of ideal synthetic images of major mergers and non-mergers selected from the Next Generation Illustris Simulations (IllustrisTNG) to include major observational effects. We then train deep convolutional neural networks (CNNs) using realistic mock observations of galaxy samples from the simulations. Subsequently, we apply the trained CNNs to real the Kilo-Degree Survey (KiDS) images of galaxies selected from the Galaxy And Mass Assembly (GAMA) survey. Based on the major merger samples, which are detected in a consistent manner in the observations and simulations, we determine the dependence of major merger fraction on stellar mass at z around 0.15 and make comparisons between the two. Results. The detected major merger fraction in the GAMA/KiDS observations has a fairly mild decreasing trend with increasing stellar mass over the mass range 10^9 < M_sun < M_star < 10^11.5 M_sun. There is good agreement in the mass dependence of the major merger fraction in the GAMA/KiDS observations and the IllustrisTNG simulations over 10^9.5 M_sun < M_star < 10^10.5 M_sun. However, the observations and the simulations show some differences at M_star > 10^10.5M_sun, possibly due to the supermassive blackhole feedback in its low-accretion state in the simulations which causes a sharp transition in the quenched fractions at this mass scale. The discrepancy could also be due to the relatively small volume of the simulations and/or differences in how stellar masses are measured in simulations and observations.

arXiv comment12 pages, 12 figures, accepted for publication in A&A

References in corpus (107)

• The many lives of active galactic nuclei: cooling flows, black holes and the luminosities and colours of galaxies
• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• Populating a cluster of galaxies - I. Results at z=0
• E pur si muove: Galiliean-invariant cosmological hydrodynamical simulations on a moving mesh
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• Simulating Galaxy Formation with the IllustrisTNG Model
• Hierarchical Galaxy Formation
• First results from the IllustrisTNG simulations: matter and galaxy clustering
• Detailed Decomposition of Galaxy Images. II. Beyond Axisymmetric Models
• First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies
• The hierarchical formation of the brightest cluster galaxies
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• First results from the IllustrisTNG simulations: the galaxy color bimodality
• The EAGLE simulations of galaxy formation: calibration of subgrid physics and model variations
• Properties of galaxies reproduced by a hydrodynamic simulation
• First results from the IllustrisTNG simulations: A tale of two elements -- chemical evolution of magnesium and europium
• A simple model to interpret the ultraviolet, optical and infrared emission from galaxies
• A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei
• FIRE-2 Simulations: Physics versus Numerics in Galaxy Formation
• Simba: Cosmological Simulations with Black Hole Growth and Feedback
• Galaxy and Mass Assembly (GAMA): survey diagnostics and core data release
• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• The Relationship Between Stellar Light Distributions of Galaxies and their Formation Histories
• A New Non-Parametric Approach to Galaxy Morphological Classification
• Rotation-invariant convolutional neural networks for galaxy morphology prediction
• The merger rate of galaxies in the Illustris Simulation: a comparison with observations and semi-empirical models
• Galaxy Zoo 1 : Data Release of Morphological Classifications for nearly 900,000 galaxies
• Galaxy And Mass Assembly (GAMA): end of survey report and data release 2
• Galaxy Pairs in the Sloan Digital Sky Survey I: Star Formation, AGN Fraction, and the Luminosity/Mass-Metallicity Relation
• A Merger-Driven Scenario for Cosmological Disk Galaxy Formation
• The Horizon-AGN simulation: morphological diversity of galaxies promoted by AGN feedback
• The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars
• Supermassive black holes and their feedback effects in the IllustrisTNG simulation
• The optical morphologies of galaxies in the IllustrisTNG simulation: a comparison to Pan-STARRS observations
• A New Approach to Galaxy Morphology: I. Analysis of the Sloan Digital Sky Survey Early Data Release
• Statistical Properties of Collisionless Equal- and Unequal-Mass Merger Remnants of Disk Galaxies
• A Public Ks-selected Catalog in the COSMOS/UltraVISTA Field: Photometry, Photometric Redshifts and Stellar Population Parameters
• Evolution of galaxy stellar masses and star formation rates in the EAGLE simulations
• GAMA: towards a physical understanding of galaxy formation
• The Fundamental Scaling Relations of Elliptical Galaxies
• A physical model for cosmological simulations of galaxy formation: multi-epoch validation
• The fourth data release of the Kilo-Degree Survey: ugri imaging and nine-band optical-IR photometry over 1000 square degrees
• Efficient 3D NLTE dust radiative transfer with SKIRT
• SKIRT: an Advanced Dust Radiative Transfer Code with a User-Friendly Architecture
• The star-formation activity of IllustrisTNG galaxies: main sequence, UVJ diagram, quenched fractions, and systematics
• A catalog of visual-like morphologies in the 5 CANDELS fields using deep-learning
• Cold flows and the first quasars
• The Current Status of Galaxy Formation
• Kinemetry of SINS High-Redshift Star-Forming Galaxies: Distinguishing Rotating Disks from Major Mergers
• The Greater Impact of Mergers on the Growth of Massive Galaxies: Implications for Mass Assembly and Evolution Since z~1
• The Deep2 Galaxy Redshift Survey: Evolution of Close Galaxy Pairs and Major-Merger Rates Up to z ~ 1.2
• The star formation main sequence and stellar mass assembly of galaxies in the Illustris simulation
• The Nearly Universal Merger Rate of Dark Matter Haloes in Lambda-CDM Cosmology
• Galaxy growth in the concordance $\Lambda$CDM cosmology
• Metallicity and Nuclear Star Formation in Nearby Galaxy Pairs: Evidence for Tidally Induced Gas Flows
• Discriminating Between the Physical Processes that Drive Spheroid Size Evolution
• The Metallicity Evolution of Interacting Galaxies
• Star-galaxy Classification Using Deep Convolutional Neural Networks
• The relationship between black hole mass and galaxy properties: Examining the black hole feedback model in IllustrisTNG
• The role of mergers and halo spin in shaping galaxy morphology
• A chronicle of galaxy mass assembly in the EAGLE simulation
• Finding Strong Gravitational Lenses in the Kilo Degree Survey with Convolutional Neural Networks
• Observational constraints on the merger history of galaxies since $z\approx 6$: Probabilistic galaxy pair counts in the CANDELS fields
• Minor Galaxy Interactions: Star Formation Rates and Galaxy Properties
• Galaxy And Mass Assembly (GAMA): Accurate Panchromatic Photometry from Optical Priors using LAMBDAR
• Galaxy And Mass Assembly (GAMA): Panchromatic Data Release (far-UV --- far-IR) and the low-z energy budget
• Mapping galaxy encounters in numerical simulations: The spatial extent of induced star formation
• The Luminosity Dependence of the Galaxy Merger Rate
• Using transfer learning to detect galaxy mergers
• Galaxy And Mass Assembly (GAMA): The galaxy stellar mass function to $z=0.1$ from the r-band selected equatorial regions
• Effect of galaxy mergers on star formation rates
• Resolving the Discrepancy of Galaxy Merger Fraction Measurements at z ~ 0 - 3
• The CFHTLS Deep Catalog of Interacting Galaxies I. Merger Rate Evolution to z=1.2
• The halo merger rate in the Millennium Simulation and implications for observed galaxy merger fractions
• Galaxy Pairs in COSMOS -- Merger Rate Evolution Since z=1
• A consistent measure of the merger histories of massive galaxies using close-pair statistics I: Major mergers at $z<3.5$
• Deep learning predictions of galaxy merger stage and the importance of observational realism
• Galaxy pairs in the Sloan digital sky survey - VII: The merger -- luminous infra-red galaxy connection
• Galaxy And Mass Assembly (GAMA): Refining the Local Galaxy Merger Rate using Morphological Information
• Mergers Do Trigger AGNs out to z $\sim$ 0.6
• Understanding the Structural Scaling Relations of Early-Type Galaxies
• The merger-driven evolution of massive galaxies
• Spatially resolved star formation and metallicity profiles in post-merger galaxies from MaNGA
• The diminishing importance of major galaxy mergers at higher redshifts
• Close Galaxy Counts as a Probe of Hierarchical Structure Formation
• Galaxy Merger Rates up to z $\sim$ 3 using a Bayesian Deep Learning Model $-$ A Major-Merger classifier using IllustrisTNG Simulation data
• Identifying Galaxy Mergers in Observations and Simulations with Deep Learning
• The Destruction of Thin Stellar Disks Via Cosmologically Common Satellite Accretion Events
• Merger-Induced Metallicity Dilution in Cosmological Galaxy Formation Simulations
• Redshift Evolution of the Merger Fraction of Galaxies in CDM Cosmologies
• Interacting galaxies in the IllustrisTNG simulations -- I: Triggered star formation in a cosmological context
• HOLISMOKES -- II. Identifying galaxy-scale strong gravitational lenses in Pan-STARRS using convolutional neural networks
• Galaxy mergers in EAGLE do not induce a significant amount of black hole growth yet do increase the rate of luminous AGN
• The Dynamics of Galaxy Pairs in a Cosmological Setting
• Distinguishing Mergers and Disks in High Redshift Observations of Galaxy Kinematics
• GAMA/G10-COSMOS/3D-HST: Evolution of the galaxy stellar mass function over 12.5Gyrs
• SAURON's Challenge for the Major Merger Scenario of Elliptical Galaxy Formation
• Bar Formation from Galaxy Flybys
• Automated Distant Galaxy Merger Classifications from Space Telescope Images using the Illustris Simulation
• The Frequency of Dwarf Galaxy Multiples at Low Redshift in SDSS vs. Cosmological Expectations
• Using Convolutional Neural Networks to identify Gravitational Lenses in Astronomical images
• Deep Transfer Learning for Star Cluster Classification: I. Application to the PHANGS-HST Survey
• A First Look at Galaxy Flyby Interactions: I. Characterizing the Frequency of Flybys in a Cosmological Context
• NIR Luminosity Function of Galaxies in Close Major-Merger Pairs and Mass Dependence of Merger Rate
• First Results from the KMOS Lens-Amplified Spectroscopic Survey (KLASS): Kinematics of Lensed Galaxies at Cosmic Noon
• Galaxy interactions in IllustrisTNG-100, I: The power and limitations of visual identification
• The Clustering and Host Halos of Galaxy Mergers at High Redshift

Cited by in corpus (17)

• Convolutional neural network identification of galaxy post-mergers in UNIONS using IllustrisTNG
• Hidden depths in the local Universe: The Stellar Stream Legacy Survey
• DeepMerge II: Building Robust Deep Learning Algorithms for Merging Galaxy Identification Across Domains
• Morphological signatures of mergers in the TNG50 simulation and the Kilo-Degree Survey: the merger fraction from dwarfs to Milky Way-like galaxies
• Star formation characteristics of CNN-identified post-mergers in the Ultraviolet Near Infrared Optical Northern Survey (UNIONS)
• North Ecliptic Pole merging galaxy catalogue
• AGN in post-mergers from the Ultraviolet Near Infrared Optical Northern Survey
• A Census of WISE-selected Dual and Offset AGN Across the Sky: New Constraints on Merger-Driven Triggering of Obscured AGN
• Dust and Power: Unravelling the merger - active galactic nucleus connection in the second half of cosmic history
• Galaxy merger challenge: A comparison study between machine learning-based detection methods
• ERGO-ML: Comparing IllustrisTNG and HSC galaxy images via contrastive learning
• Merger identification through photometric bands, colours, and their errors
• Determining the time before or after a galaxy merger event
• A post-merger enhancement only in star-forming Type 2 Seyfert galaxies: the deep learning view
• Classifying merger stages with adaptive deep learning and cosmological hydrodynamical simulations
• The major merger-active galactic nucleus connection up to the cosmic noon
• A Simulation Driven Deep Learning Approach for Separating Mergers and Star Forming Galaxies: The Formation Histories of Clumpy Galaxies in all the CANDELS Fields