Title: On the galaxy–halo connection in the EAGLE simulation

Abstract

Empirical models of galaxy formation require assumptions about the correlations between galaxy and halo properties. These may be calibrated against observations or inferred from physical models such as hydrodynamical simulations. In this Letter, we use the EAGLE simulation to investigate the correlation of galaxy size with halo properties. We motivate this analysis by noting that the common assumption of angular momentum partition between baryons and dark matter in rotationally supported galaxies overpredicts both the spread in the stellar mass-size relation and the anticorrelation of size and velocity residuals, indicating a problem with the galaxy-halo connection it implies. We find the EAGLE galaxy population to perform significantly better on both statistics, and trace this success to the weakness of the correlations of galaxy size with halo mass, concentration and spin at fixed stellar mass. Using these correlations in empirical models will enable fine-grained aspects of galaxy scalings to be matched.

Authors:

Desmond, Harry  ^[1];

• Search DOE PAGES for author "Desmond, Harry"
• Search DOE PAGES for ORCID "0000-0003-0685-9791"

Mao, Yao -Yuan  ^[2];

• Search DOE PAGES for author "Mao, Yao -Yuan"
• Search DOE PAGES for ORCID "0000-0002-1200-0820"

Wechsler, Risa H. ^[1]; Crain, Robert A.  ^[3];

• Search DOE PAGES for author "Crain, Robert A."
• Search DOE PAGES for ORCID "0000-0001-6258-0344"

Schaye, Joop  ^[4]

• Search DOE PAGES for author "Schaye, Joop"
• Search DOE PAGES for ORCID "0000-0002-0668-5560"

---

+ Show Author Affiliations

1. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
2. Univ. of Pittsburgh, Pittsburgh, PA (United States); Pittsburgh Particle Physics, Pittsburgh, PA (United States)
3. Liverpool John Moores Univ., Liverpool (United Kingdom)
4. Leiden Univ., Leiden (The Netherlands)

Publication Date:

Tue Jun 13 00:00:00 EDT 2017

Research Org.:

SLAC National Accelerator Lab., Menlo Park, CA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1407427

Alternate Identifier(s):

OSTI ID: 1418321

Grant/Contract Number:  

AC02-76SF00515

Resource Type:

Accepted Manuscript

Journal Name:

Monthly Notices of the Royal Astronomical Society: Letters

Additional Journal Information:

Journal Volume: 471; Journal Issue: 1; Journal ID: ISSN 1745-3925

Publisher:

Royal Astronomical Society

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; galaxies: formation; galaxies: fundamental parameters; galaxies: haloes; galaxies: kinematics and dynamics; galaxies: statistics; dark matter