Cookies

We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.


Durham Research Online
You are in:

The impact of assembly bias on the galaxy content of dark matter halos.

Zehavi, Idit and Contreras, Sergio and Padilla, Nelson and Smith, Nicholas J. and Baugh, Carlton M. and Norberg, Peder (2018) 'The impact of assembly bias on the galaxy content of dark matter halos.', Astrophysical journal., 853 (1). p. 84.

Abstract

We study the dependence of the galaxy content of dark matter halos on large-scale environment and halo formation time using semi-analytic galaxy models applied to the Millennium simulation. We analyze subsamples of halos at the extremes of these distributions and measure the occupation functions for the galaxies they host. We find distinct differences among these occupation functions. The main effect with environment is that central galaxies (and in one model, also the satellites) in denser regions start populating lower-mass halos. A similar, but significantly stronger, trend exists with halo age, where early-forming halos are more likely to host central galaxies at lower halo mass. We discuss the origin of these trends and the connection to the stellar mass–halo mass relation. We find that, at fixed halo mass, older halos and to some extent also halos in dense environments tend to host more massive galaxies. Additionally, we see a reverse trend for the occupation of satellite galaxies where early-forming halos have fewer satellites, likely due to having more time for them to merge with the central galaxy. We describe these occupancy variations in terms of the changes in the occupation function parameters, which can aid in constructing realistic mock galaxy samples. Finally, we study the corresponding galaxy auto- and cross-correlation functions of the different samples and elucidate the impact of assembly bias on galaxy clustering. Our results can inform theoretical modeling of galaxy assembly bias and attempts to detect it in the real universe.

Item Type:Article
Full text:(VoR) Version of Record
Download PDF
(5350Kb)
Status:Peer-reviewed
Publisher Web site:https://doi.org/10.3847/1538-4357/aaa54a
Publisher statement:© 2018. The American Astronomical Society. All rights reserved.
Date accepted:02 January 2018
Date deposited:08 February 2018
Date of first online publication:25 January 2018
Date first made open access:08 February 2018

Save or Share this output

Export:
Export
Look up in GoogleScholar