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A constant dark matter halo surface density in galaxies

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journal contribution
posted on 24.10.2012, 09:15 by F. Donato, G. Gentile, P. Salucci, Frigerio Martins C., M. I. Wilkinson, G. Gilmore, E. K. Grebel, A. Koch, R. Wyse
We confirm and extend the recent finding that the central surface density μ0D≡r0ρ0 of galaxy dark matter haloes, where r0 and ρ0 are the halo core radius and central density, is nearly constant and independent of galaxy luminosity. Based on the co-added rotation curves (RCs) of ∼1000 spiral galaxies, the mass models of individual dwarf irregular and spiral galaxies of late and early types with high-quality RCs, and the galaxy–galaxy weak-lensing signals from a sample of spiral and elliptical galaxies, we find that log μ0D= 2.15 ± 0.2 in units of log(M⊙ pc−2). We also show that the observed kinematics of Local Group dwarf spheroidal galaxies are consistent with this value. Our results are obtained for galactic systems spanning over 14 mag, belonging to different Hubble types and whose mass profiles have been determined by several independent methods. In the same objects, the approximate constancy of μ0D is in sharp contrast to the systematical variations, by several orders of magnitude, of galaxy properties, including ρ0 and central stellar surface density.

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Citation

Monthly Notices of the Royal Astronomical Society, 2009, 397 (3), pp. 1169-1176

Version

VoR (Version of Record)

Published in

Monthly Notices of the Royal Astronomical Society

Publisher

Oxford University Press (OUP)

issn

0035-8711

eissn

1365-2966

Copyright date

2009

Available date

24/10/2012

Publisher version

http://mnras.oxfordjournals.org/content/397/3/1169

Language

en

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