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

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. Here by, using these correlations in empirical models will enable fine-grained aspects of galaxy scalings to be matched.
ORCiD logo [1] ; ORCiD logo [2] ;  [1] ; ORCiD logo [3] ; ORCiD logo [4]
  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:
Grant/Contract Number:
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
Royal Astronomical Society
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; galaxies: formation; galaxies: fundamental parameters; galaxies: haloes; galaxies: kinematics and dynamics; galaxies: statistics; dark matter
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1418321