TY  - JOUR
SN  - 1365-2966
N1  - This article has been accepted for publication in  Monthly Notices of the Royal Astronomical Society ©: 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
ID  - discovery1447158
AV  - public
JF  - Monthly Notices of the Royal Astronomical Society
EP  - 127
N2  - We study the total density distribution in the central regions (?1 effective radius, Re) of earlytype galaxies (ETGs), using data from SPIDER and ATLAS3D. Our analysis extends the range of galaxy stellar mass (M*) probed by gravitational lensing, down to ~1010M. We model each galaxy with two components (dark matter halo + stars), exploring different assumptions for the dark matter halo profile (i.e. NFW, NFW-contracted, and Burkert profiles), and leaving stellar mass-to-light (M*/L) ratios as free fitting parameters to the data. For all plausible halo models, the best-fitting M*/L, normalized to that for a Chabrier initial mass function, increases systematically with galaxy size and mass. For anNFWprofile, the slope of the total mass profile is non-universal, independently of several ingredients in the modelling (e.g. halo contraction, anisotropy, and rotation velocity in ETGs). For the most massive (M* ~ 1011.5M) or largest (Re ~ 15 kpc) ETGs, the profile is isothermal in the central regions (~Re/2), while for the low-mass (M* ~ 1010.2M) or smallest (Re ~ 0.5 kpc) systems, the profile is steeper than isothermal, with slopes similar to those for a constant-M/L profile. For a steeper concentration- mass relation than that expected from simulations, the correlation of density slope with galaxy mass tends to flatten, while correlations with Re and velocity dispersions are more robust. Our results clearly point to a 'non-homology' in the total mass distribution of ETGs, which simulations of galaxy formation suggest may be related to a varying role of dissipation with galaxy mass. 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.
VL  - 445
SP  - 115
UR  - http://dx.doi.org/10.1093/mnras/stu1616
TI  - Systematic variations of central mass density slopes in early-type galaxies
KW  - Galaxies: elliptical and lenticular
KW  -  cD ? galaxies: evolution ? galaxies: general.
IS  - 1
A1  - Tortora, C
A1  - La Barbera, F
A1  - Napolitano, NR
A1  - Romanowsky, AJ
A1  - Ferreras, I
A1  - de Carvalho, RR
Y1  - 2014/09/23/
ER  -