eprintid: 1447158 rev_number: 41 eprint_status: archive userid: 608 dir: disk0/01/44/71/58 datestamp: 2014-09-06 19:14:02 lastmod: 2021-10-24 23:46:18 status_changed: 2017-01-23 14:24:08 type: article metadata_visibility: show item_issues_count: 0 creators_name: Tortora, C creators_name: La Barbera, F creators_name: Napolitano, NR creators_name: Romanowsky, AJ creators_name: Ferreras, I creators_name: de Carvalho, RR title: Systematic variations of central mass density slopes in early-type galaxies ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F60 keywords: Galaxies: elliptical and lenticular, cD – galaxies: evolution – galaxies: general. note: 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. abstract: 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. date: 2014-09-23 official_url: http://dx.doi.org/10.1093/mnras/stu1616 vfaculties: VMPS oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green article_type_text: Journal Article verified: verified_manual elements_source: arXiv elements_id: 972571 doi: 10.1093/mnras/stu1616 lyricists_name: Ferreras, Ignacio lyricists_id: IFERR71 full_text_status: public publication: Monthly Notices of the Royal Astronomical Society volume: 445 number: 1 pagerange: 115-127 issn: 1365-2966 citation: Tortora, C; La Barbera, F; Napolitano, NR; Romanowsky, AJ; Ferreras, I; de Carvalho, RR; (2014) Systematic variations of central mass density slopes in early-type galaxies. Monthly Notices of the Royal Astronomical Society , 445 (1) pp. 115-127. 10.1093/mnras/stu1616 <https://doi.org/10.1093/mnras%2Fstu1616>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1447158/1/Tortora_Systematic%20variations%20of%20central%20mass%20density%20slopes%20in%20early-type%20galaxies.pdf