Quadratic genetic modifications: a streamlined route to cosmological simulations with controlled merger history. Issue 1 (24th October 2017)

• Record Type: Journal Article
• Authors: Rey, Martin P.; Pontzen, Andrew
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 474:Issue 1(2018)
• Page Start: 45
• Page End: 54
• Publication Date: 2017-10-24
• Subjects: methods: numerical -- galaxies: evolution -- galaxies: formation -- dark matter; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stx2744
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: Recent work has studied the interplay between a galaxy's history and its observable properties using 'genetically modified' cosmological zoom simulations. The approach systematically generates alternative histories for a halo, while keeping its cosmological environment fixed. Applications to date altered linear properties of the initial conditions, such as the mean overdensity of specified regions; we extend the formulation to include quadratic features, such as local variance, that determines the overall importance of smooth accretion relative to mergers in a galaxy's history. We introduce an efficient algorithm for this new class of modification and demonstrate its ability to control the variance of a region in a one-dimensional toy model. Outcomes of this work are twofold: (i) a clarification of the formulation of genetic modifications and (ii) a proof of concept for quadratic modifications leading the way to a forthcoming implementation in cosmological simulations.