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Dark matter in disc galaxies - II. Density profiles as constraints on feedback scenarios

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journal contribution
posted on 13.10.2015, 11:46 by P. R. Hague, Mark I. Wilkinson
The disparity between the density profiles of galactic dark matter haloes predicted by dark matter only cosmological simulations and those inferred from rotation curve decomposition, the so-called cusp–core problem, suggests that baryonic physics has an impact on dark matter density in the central regions of galaxies. Using a Markov Chain Monte Carlo analysis of galactic rotation curves we constrain density profiles and an estimated minimum radius for baryon influence, r[subscript: 1], which we couple with a feedback model to give an estimate of the fraction of matter within that radius that must be expelled to produce the observed halo profile. We examine the rotation curves of eight galaxies taken from the THINGS (The HI Nearby Galaxy Survey) data set and determine constraints on the radial density profiles of their dark matter haloes. For some of the galaxies, both cored haloes and cosmological ρ ∝ r[superscript: −1] cusps are excluded which requires finely tuned baryonic feedback. For galaxies which exhibit extended cores in their haloes (e.g. NGC 925), the use of a split power-law halo profile yields models without the unphysical, sharp features seen in models based on the Einasto profile. We have found there is no universal halo profile which can describe all the galaxies studied here.

History

Citation

Monthly Notices of the Royal Astronomical Society, 2014, 443 (4), pp. 3712-3727 (16)

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

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

Acceptance date

07/07/2014

Copyright date

2014

Available date

13/10/2015

Publisher version

http://mnras.oxfordjournals.org/content/443/4/3712

Language

en