skip to main content

Title: MATCHING THE DARK MATTER PROFILES OF dSph GALAXIES WITH THOSE OF SIMULATED SATELLITES: A TWO-PARAMETER COMPARISON

We compare the dark matter halos’ structural parameters derived for four Milky Way dwarf spheroidal galaxies to those of subhalos found in cosmological N-body simulations. We confirm that estimates of the mass at a single fixed radius are fully consistent with the observations. However, when a second structural parameter such as the logarithmic slope of the dark halo density profile measured close to the half-light radius is included in the comparison, we find little to no overlap between the satellites and the subhalos. Typically the right mass subhalos have steeper profiles at these radii than measurements of the dSph suggest. Using energy arguments we explore if it is possible to solve this discrepancy by invoking baryonic effects. Assuming that feedback from supernovae (SNe) can lead to a reshaping of the halos, we compute the required efficiency and find entirely plausible values for a significant fraction of the subhalos and even as low as 0.1%. This implies that care must be taken not to exaggerate the effect of SNe feedback as this could make the halos too shallow. These results could be used to calibrate and possibly constrain feedback recipes in hydrodynamical simulations.
Authors:
;  [1] ;  [2]
  1. Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV Groningen (Netherlands)
  2. Department of Astronomy, University of Wisconsin, 2535 Sterling Hall, 475 N. Charter Street, Madison, WI 53076 (United States)
Publication Date:
OSTI Identifier:
22518671
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 814; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BARYONS; COMPARATIVE EVALUATIONS; COSMOLOGY; DENSITY; EFFICIENCY; HYDRODYNAMICS; MASS; MILKY WAY; NONLUMINOUS MATTER; SATELLITES; SUPERNOVAE; VISIBLE RADIATION