Mon. Not. R. Astron. Soc., 464, 3742-3756 (2017/January-3)
The co-evolution of total density profiles and central dark matter fractions in simulated early-type galaxies.
REMUS R.-S., DOLAG K., NAAB T., BURKERT A., HIRSCHMANN M., HOFFMANN T.L. and JOHANSSON P.H.
Abstract (from CDS):
We present evidence from cosmological hydrodynamical simulations for a co-evolution of the slope of the total (dark and stellar) mass density profile, γtot, and the dark matter fraction within the half-mass radius, fDM, in early-type galaxies. The relation can be described as γtot = A fDM + B for all systems at all redshifts. The trend is set by the decreasing importance of gas dissipation towards lower redshifts and for more massive systems. Early-type galaxies are smaller, more concentrated, have lower fDM and steeper γtot at high redshifts and at lower masses for a given redshift; fDM and γtot are good indicators for growth by 'dry' merging. The values for A and B change distinctively for different feedback models, and this relation can be used as a test for such models. A similar correlation exists between γtot and the stellar mass surface density Σ*. A model with weak stellar feedback and feedback from black holes is in best agreement with observations. All simulations, independent of the assumed feedback model, predict steeper γtot and lower fDM at higher redshifts. While the latter is in agreement with the observed trends, the former is in conflict with lensing observations, which indicate constant or decreasing γtot. This discrepancy is shown to be artificial: the observed trends can be reproduced from the simulations using observational methodology to calculate the total density slopes.
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
methods: numerical - galaxies: evolution - galaxies: formation - dark matter - dark matter
View the reference in ADS
To bookmark this query, right click on this link: simbad:2017MNRAS.464.3742R and select 'bookmark this link' or equivalent in the popup menu