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Related papers: Identifying mergers using non-parametric morpholog…

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Merging galaxies play a key role in galaxy evolution, and progress in our understanding of galaxy evolution is slowed by the difficulty of making accurate galaxy merger identifications. We use GADGET-3 hydrodynamical simulations of merging…

Astrophysics of Galaxies · Physics 2020-03-18 Nevin , R. , Blecha , L. , Comerford , J. , Greene , J

We present two new non-parametric methods for quantifying galaxy morphology: the relative distribution of the galaxy pixel flux values (the Gini coefficient or G) and the second-order moment of the brightest 20% of the galaxy's flux (M20).…

Astrophysics · Physics 2010-04-06 Jennifer M. Lotz , Joel Primack , Piero Madau

It is difficult to accurately identify galaxy mergers and it is an even larger challenge to classify them by their mass ratio or merger stage. In previous work we used a suite of simulated mergers to create a classification technique that…

Astrophysics of Galaxies · Physics 2023-04-12 R. Nevin , L. Blecha , J. Comerford , J. Simon , B. A. Terrazas , R. S. Barrows , J. A. Vázquez-Mata

Utilizing a high-resolution (114 pc/h) adaptive mesh-refinement cosmological galaxy formation simulation of the standard cold dark matter model with a large (2000-3000 galaxies with stellar mass greater than 1e9 Msun) statistical sample, we…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-04 Renyue Cen

Spatially resolved kinematics have been used to determine the dynamical status of star-forming galaxies with ambiguous morphologies, and constrain the importance of galaxy interactions during the assembly of galaxies. However, measuring the…

Understanding the role of mergers in galaxy formation is one of the most outstanding problems in extragalactic astronomy. While we now have an idea for how the merger fraction evolves at redshifts z < 3, converting this merger fraction into…

Astrophysics of Galaxies · Physics 2015-05-13 Christopher J. Conselice

We present new results on the physical nature of infrared-luminous sources at 0.5<z<2.8 as revealed by HST/NICMOS imaging and IRS mid-infrared spectroscopy. Our sample consists of 134 galaxies selected at 24\mum with a flux of S(24\mum) >…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Michel Zamojski , Lin Yan , Kalliopi Dasyra , Anna Sajina , Jason Surace , Tim Heckman , George Helou

We apply a new approach to quantifying galaxy morphology and identifying galaxy mergers to the rest-frame far-ultraviolet images of 82 z ~ 4 Lyman break galaxies (LBGs) and 55 1.2 < z < 1.8 emission-line galaxies in the GOODS and Ultra Deep…

Astrophysics · Physics 2007-05-23 J. M. Lotz , P. Madau , M. Giavalisco , J. Primack , H. C. Ferguson

The morphology of galaxies can be quantified to some degree using a set of scale-invariant parameters. Concentration (C), Asymmetry (A), Smoothness (S), the Gini index (G), relative contribution of the brightest pixels to the second order…

HST images of a sample of 285 galaxies with measured z from the CFRS and Autofib-LDSS redshift surveys are analysed to derive the evolution of the merger fraction out to z~1. We have performed visual and machine-based merger…

We present the results of a series of empirical computations regarding the role of major mergers in forming the stellar masses of modern galaxies based on measurements of galaxy merger and star formation histories from z~0.5-3. We…

Astrophysics · Physics 2009-11-13 Christopher J. Conselice

Galaxy mergers are thought to be one of the main mechanisms of the mass assembly of galaxies. Recently, many works have suggested a possible increase in the fraction of major mergers in the early Universe, reviving the debate on which…

Active galactic nuclei (AGN), particularly the most luminous AGN, are commonly assumed to be triggered through major mergers, however observational evidence for this scenario is mixed. To investigate any influence of galaxy mergers on AGN…

Astrophysics of Galaxies · Physics 2017-07-05 Tim Hewlett , Carolin Villforth , Vivienne Wild , Jairo Mendez-Abreu , Milena Pawlik , Kate Rowlands

Galaxy merging is the late time manifestation of the galaxy formation process and likely significantly effects $z<1$ galaxies. A ``maximum reasonable rate'' model for merging finds a $\sim2$ mag K band increase in the luminosities of dwarf…

Astrophysics · Physics 2016-08-30 R. G. Carlberg

The classification of galaxy mergers and isolated disks is key for understanding the relative importance of galaxy interactions and secular evolution during the assembly of galaxies. The kinematic properties of galaxies as traced by…

We present a detailed analysis of predicted galaxy-galaxy merger fractions and rates in the Millennium simulation and compare these with the most up to date observations of the same quantities up to z~3. We carry out our analysis by…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-29 Serena Bertone , Christopher J. Conselice

Calculating the galaxy merger rate requires both a census of galaxies identified as merger candidates, and a cosmologically-averaged `observability' timescale T_obs(z) for identifying galaxy mergers. While many have counted galaxy mergers…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jennifer M. Lotz , Patrik Jonsson , T. J. Cox , Darren Croton , Joel R. Primack , Rachel S. Somerville , Kyle Stewart

We investigate the fraction of close pairs and morphologically identified mergers on and above the star-forming main sequence (MS) at 0.2$\leq z\leq$2.0. The novelty of our work lies in the use of a non-parametric morphological…

We explore the galaxy-galaxy merger rate with the empirical model for galaxy formation, Emerge. On average, we find that between $2$ per cent and $20$ per cent of massive galaxies ($\log_{10}(m_{*}/M_{\odot}) \geq 10.3$) will experience a…

Astrophysics of Galaxies · Physics 2021-01-19 Joseph A. O'Leary , Benjamin P. Moster , Thorsten Naab , Rachel S. Somerville

We use hydrodynamic simulations to examine how the baryonic components of galaxies are assembled, focusing on the relative importance of mergers and smooth accretion in the formation of ~L_* systems. In our primary simulation, which models…

Astrophysics · Physics 2009-11-06 Chigurupati Murali , Neal Katz , Lars Hernquist , David H. Weinberg , Romeel Dave