Galaxy merger
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The Galaxy in Context: Structural, Kinematic, and Integrated Properties Open
Our Galaxy, the Milky Way, is a benchmark for understanding disk galaxies. It is the only galaxy whose formation history can be studied using the full distribution of stars from faint dwarfs to supergiants. The oldest components provide us…
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Theoretical Challenges in Galaxy Formation Open
Numerical simulations have become a major tool for understanding galaxy formation and evolution. Over the decades the field has made significant progress. It is now possible to simulate the formation of individual galaxies and galaxy popul…
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The Galaxy platform for accessible, reproducible, and collaborative data analyses: 2024 update Open
Galaxy (https://galaxyproject.org) is deployed globally, predominantly through free-to-use services, supporting user-driven research that broadens in scope each year. Users are attracted to public Galaxy services by platform stability, too…
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The Horizon-AGN simulation: morphological diversity of galaxies promoted by AGN feedback Open
The interplay between cosmic gas accretion on to galaxies and galaxy mergers\ndrives the observed morphological diversity of galaxies. By comparing the\nstate-of-the-art hydrodynamical cosmological simulations Horizon-AGN and\nHorizon-noAG…
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The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars Open
We use the Illustris simulation to study the relative contributions of in situ star formation and stellar accretion to the build-up of galaxies over an unprecedentedly wide range of masses (M* = 109-1012 M⊙), galaxy types, environments, an…
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Supermassive black holes and their feedback effects in the IllustrisTNG simulation Open
We study the population of supermassive black holes (SMBHs) and their effects\non massive central galaxies in the IllustrisTNG cosmological hydrodynamical\nsimulations of galaxy formation. The employed model for SMBH growth and\nfeedback a…
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The dark nemesis of galaxy formation: why hot haloes trigger black hole growth and bring star formation to an end Open
Galaxies fall into two clearly distinct types: `blue-sequence' galaxies that\nare rapidly forming young stars, and `red-sequence' galaxies in which star\nformation has almost completely ceased. Most galaxies more massive than\n$3\\times10^…
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SEMI-ANALYTIC GALAXY EVOLUTION (SAGE): MODEL CALIBRATION AND BASIC RESULTS Open
This paper describes a new publicly available codebase for modeling galaxy formation in a cosmological context, the "Semi-Analytic Galaxy Evolution" model, or sage for short.5 sage is a significant update to the 2006 model of Croton et al.…
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Galaxy And Mass Assembly (GAMA): Data Release 4 and the <i>z</i> < 0.1 total and <i>z</i> < 0.08 morphological galaxy stellar mass functions Open
In Galaxy And Mass Assembly Data Release 4 (GAMA DR4), we make available our full spectroscopic redshift sample. This includes 248 682 galaxy spectra, and, in combination with earlier surveys, results in 330 542 redshifts across five sky r…
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Growing supermassive black holes in the late stages of galaxy mergers are heavily obscured Open
Mergers of galaxies are thought to cause significant gas inflows to the inner\nparsecs, which can activate rapid accretion onto supermassive black holes\n(SMBHs), giving rise to Active Galactic Nuclei (AGN). During a significant\nfraction …
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The role of mergers and halo spin in shaping galaxy morphology Open
Mergers and the spin of the dark matter halo are factors traditionally believed to determine the morphology of galaxies within a $\Lambda$CDM cosmology. We study this hypothesis by considering approximately 18,000 central galaxies at $z=0$…
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Galaxy interactions trigger rapid black hole growth: An unprecedented view from the Hyper Suprime-Cam survey Open
Collisions and interactions between gas-rich galaxies are thought to be pivotal stages in their formation and evolution, causing the rapid production of new stars, and possibly serving as a mechanism for fueling supermassive black holes (B…
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A chronicle of galaxy mass assembly in the EAGLE simulation Open
We analyse the mass assembly of central galaxies in the Evolution and Assembly of Galaxies and their Environments (EAGLE) hydrodynamical simulations. We build merger trees to connect galaxies to their progenitors at different redshifts and…
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A definitive merger-AGN connection at z ∼ 0 with CFIS: mergers have an excess of AGN and AGN hosts are more frequently disturbed Open
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Galaxy assembly, stellar feedback and metal enrichment: the view from the gaea model Open
One major problem of current theoretical models of galaxy formation is given\nby their inability to reproduce the apparently `anti-hierarchical' evolution of\ngalaxy assembly: massive galaxies appear to be in place since $z\\sim 3$, while\…
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A dust-enshrouded tidal disruption event with a resolved radio jet in a galaxy merger Open
An expanding radio jet from a destroyed star If a star gets too close to a supermassive black hole, it gets ripped apart in a tidal disruption event (TDE). Mattila et al. discovered a transient source in the merging galaxy pair Arp 299, wh…
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Bulgeless Giant Galaxies Challenge Our Picture Of Galaxy Formation By Hierarchical Clustering Open
To better understand the prevalence of bulgeless galaxies in the nearby field, we dissect giant Sc-Scd galaxies with Hubble Space Telescope (HST) photometry and Hobby-Eberly Telescope (HET) spectroscopy. We use the HET High Resolution Spec…
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On the frequency, intensity, and duration of starburst episodes triggered by galaxy interactions and mergers Open
We investigate the intensity enhancement and the duration of starburst episodes triggered by major galaxy interactions and mergers. We analyze two large statistical datasets of numerical simulations. These have been obtained using two inde…
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Chemodynamics of barred galaxies in cosmological simulations: On the Milky Way’s quiescent merger history and <i>in-situ</i> bulge Open
We explore the chemodynamical properties of a sample of barred galaxies in the Auriga magnetohydrodynamical cosmological zoom-in simulations, which form boxy/peanut (b/p) bulges, and compare these to the Milky Way (MW). We show that the Au…
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ALMA uncovers the [C <span>ii</span>] emission and warm dust continuum in a <i>z</i> = 8.31 Lyman break galaxy Open
We report on the detection of the [C ii] 157.7 μm emission from the Lyman break galaxy (LBG) MACS0416_Y1 at z = 8.3113, by using the Atacama Large Millimeter/submillimeter Array (ALMA). The luminosity ratio of [O iii] 88 μm (from previous …
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Simulations of ram-pressure stripping in galaxy-cluster interactions Open
Observationally, the quenching of star-forming galaxies appears to depend both on their mass and environment. The exact cause of the environmental dependence is still poorly understood, yet semi-analytic models (SAMs) of galaxy formation n…
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Quantifying the impact of mergers on the angular momentum of simulated galaxies Open
We use eagle to quantify the effect galaxy mergers have on the stellar specific angular momentum of galaxies, jstars. We split mergers into dry (gas-poor)/wet (gas-rich), major/minor and different spin alignments and orbital parameters. We…
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Dark-ages reionization and galaxy formation simulation – III. Modelling galaxy formation and the epoch of reionization Open
We introduce MERAXES, a new, purpose-built semi-analytic galaxy formation model designed for studying galaxy growth during reionization. MERAXES is the first model of its type to include a temporally and spatially coupled treatment of reio…
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RESOLVING THE DISCREPANCY OF GALAXY MERGER FRACTION MEASUREMENTS AT z ∼ 0–3 Open
We measure the merger fraction of massive galaxies using the UltraVISTA/COSMOS catalog, complemented with the deeper, higher resolution 3DHST+CANDELS catalog, presenting the largest mass-complete photometric merger sample up to . We find t…
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The role of mergers in driving morphological transformation over cosmic time Open
Understanding the processes that trigger morphological transformation is\ncentral to understanding how and why the Universe transitions from being\ndisc-dominated at early epochs to having the morphological mix that is observed\ntoday. We …
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How to quench a galaxy Open
We show how the interplay between active galactic nuclei (AGNs) and merger history determines whether a galaxy quenches star formation (SF) at high redshift. We first simulate, in a full cosmological context, a galaxy of total dynamical ma…
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High-redshift major mergers weakly enhance star formation Open
Galaxy mergers are believed to trigger strong starbursts. This is well assessed by observations in the local Universe. However, the efficiency of this mechanism has poorly been tested so far for high-redshift, actively star-forming, galaxi…
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Semi-analytic forecasts for JWST – II. Physical properties and scaling relations for galaxies at z = 4–10 Open
The long anticipated James Webb Space Telescope (JWST) will be able to directly detect large samples of galaxies at very high redshift. Using the well-established, computationally efficient Santa Cruz semi-analytic model, with recently imp…
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Deep learning predictions of galaxy merger stage and the importance of observational realism Open
Machine learning is becoming a popular tool to quantify galaxy morphologies and identify mergers. However, this technique relies on using an appropriate set of training data to be successful. By combining hydrodynamical simulations, synthe…
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Mergers, starbursts, and quenching in the simba simulation Open
We use the simba cosmological galaxy formation simulation to investigate the relationship between major mergers ($\lesssim$4:1), starbursts, and galaxy quenching. Mergers are identified via sudden jumps in stellar mass M* well above that e…