English
Related papers

Related papers: Achieving Convergence in Galaxy Formation Models b…

200 papers

We present a simple and efficient empirical algorithm for constructing dark-matter halo merger trees that reproduce the distribution of trees in the Millennium cosmological $N$-body simulation. The generated trees are significantly better…

Astrophysics · Physics 2009-11-13 Eyal Neistein , Avishai Dekel

We present a new approach to study galaxy evolution in a cosmological context. We combine cosmological merger trees and semi-analytic models of galaxy formation to provide the initial conditions for multi-merger hydrodynamic simulations. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Benjamin P. Moster , Andrea V. Macciò , Rachel S. Somerville

We show that the discrepancy between the Tully-Fisher relation and the luminosity function predicted by most phenomenological galaxy formation models is mainly due to overmerging of galaxy haloes. We have circumvented this overmerging…

Astrophysics · Physics 2009-10-31 Eelco van Kampen , Raul Jimenez , John A. Peacock

Galaxy mergers are crucial for understanding galaxy evolution, and with large upcoming datasets, automated methods such as Convolutional Neural Networks (CNNs) are essential for efficient detection. It is understood that CNNs classify…

Astrophysics of Galaxies · Physics 2026-02-17 D. M. Chudy , W. J. Pearson , A. Pollo , L. E. Suelves , B. Margalef-Bentabol , L. Wang , V. Rodriguez-Gomez , A. La Marca

We investigate the evolution of the galaxy merger rate predicted by two semi-analytical galaxy formation models implemented on the Millennium Simulation of dark matter structure growth. The fraction of merging galaxy pairs at each time-step…

Astrophysics · Physics 2008-02-21 Abilio Mateus

We have constructed merger trees for galaxies in the Illustris Simulation by directly tracking the baryonic content of subhalos. These merger trees are used to calculate the galaxy-galaxy merger rate as a function of descendant stellar…

We have made a detailed comparison of the results of large N-body simulations with the analytical description of the merging histories of dark matter halos presented in Lacey & Cole 1993, which is based on an extension of the Press-…

Astrophysics · Physics 2015-06-24 Cedric Lacey , Shaun Cole

Context. Sheen and collaborators recently found that a surprisingly large portion (38%) of massive early-type galaxies in heavy clusters show strong merger-related disturbed features. This contradicts the general understanding that massive…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Sukyoung K. Yi , Jaehyun Lee , Intae Jung , Inchan Ji , Yun-Kyeong Sheen

The merging history of dark matter halos is computed with the Merging Cell Model proposed by Rodrigues & Thomas (1996). While originally discussed in the case of scale-free power spectra, it is developed and tested here in the framework of…

Astrophysics · Physics 2009-10-31 Barbara Lanzoni , Gary A. Mamon , Bruno Guiderdoni

We present a simple and efficient method to set up spherical structure models for N-body simulations with a multimass technique. This technique reduces by a substantial factor the computer run time needed in order to resolve a given scale…

Astrophysics · Physics 2009-10-12 Marcel Zemp , Ben Moore , Joachim Stadel , C. Marcella Carollo , Piero Madau

We consider non-gravitational heating effects on galaxy clusters on the basis of the Monte-Carlo modeling of merging trees of dark matter halos combined with the thermal evolution of gas inside each halo. Under the assumption of hydrostatic…

Astrophysics · Physics 2015-06-24 Mamoru Shimizu , Tetsu Kitayama , Shin Sasaki , Yasushi Suto

A key obstacle to understanding the galaxy merger rate and its role in galaxy evolution is the difficulty in constraining the merger properties and time-scales from instantaneous snapshots of the real universe.The most common way to…

Astrophysics · Physics 2009-11-13 Jennifer M. Lotz , Patrik Jonsson , T. J. Cox , Joel R. Primack

We present a new cosmological galaxy formation model, $\nu^2$GC, as an updated version of our previous model $\nu$GC. We adopt the so-called "semi-analytic" approach, in which the formation history of dark matter halos is computed by ${\it…

Tracking the formation and evolution of dark matter haloes is a critical aspect of any analysis of cosmological $N$-body simulations. In particular, the mass assembly of a halo and its progenitors, encapsulated in the form of its merger…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-16 Sownak Bose , Daniel J. Eisenstein , Boryana Hadzhiyska , Lehman H. Garrison , Sihan Yuan

We present a method of including galaxy formation in dissipationless N-body simulations. Galaxies that form during the evolution are identified at several epochs and replaced by single massive soft particles. This allows one to produce…

Astrophysics · Physics 2007-05-23 Eelco van Kampen

A simple, 1-equation, galaxy formation model is applied to both the halo merger tree derived from a high-resolution dissipationless cosmological simulation and to 1/4 million Monte-Carlo halo merger trees. The galaxy formation model…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Gary A. Mamon , Dylan Tweed , Trinh X. Thuan , Andrea Cattaneo

Merger trees harvested from cosmological $N$-body simulations encode the assembly histories of dark matter halos over cosmic time, and are a fundamental component of semi-analytical models (SAMs) of galaxy formation. The ability to compare…

Astrophysics of Galaxies · Physics 2019-02-20 Rhys J. J. Poulton , Aaron S. G. Robotham , Chris Power , Pascal J. Elahi

We present a scheme to extend the halo mass resolution of N-body simulations of the hierarchical clustering of dark matter. The method uses the density field of the simulation to predict the number of sub-resolution dark matter haloes…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Raul E. Angulo , Carlton M. Baugh , Carlos S. Frenk , Cedric G. Lacey

A method for creating a forest of model trees to fit samples of a function defined on images is described in several steps: down-sampling the images, determining a tree's hyperplanes, applying convolutions to the hyperplanes to handle small…

Machine Learning · Computer Science 2026-01-28 William Ward Armstrong , Hongyi Li , Jun Xu

Merger trees track the evolution of halos across multiple snapshots. They assign for halos of a particular snapshot, the set of halos from previous snapshots they possibly originated from. In this work, Association rule analysis a well…

Instrumentation and Methods for Astrophysics · Physics 2017-01-18 B. Hareesh Gautham , Rahul Nigam