Open AccessThe dark matter distribution in disc galaxies
Author(s) -
Borriello Annamaria,
Salucci Paolo
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04077.x
Subject(s) - physics , astrophysics , galaxy rotation curve , dark matter halo , cuspy halo problem , dark matter , halo , galaxy , astronomy , surface brightness , hot dark matter , cosmology , dark energy
We use high‐quality optical rotation curves of nine low‐luminosity disc galaxies to obtain the velocity profiles of the surrounding dark matter haloes. We find that they increase linearly with radius at least out to the edge of the stellar disc, implying that, over the entire stellar region, the density of the dark halo is about constant. The properties of the mass structure of these haloes are similar to those found for a number of dwarf and low surface brightness galaxies, but provide a more substantial evidence of the discrepancy between the halo mass distribution predicted in the cold dark matter scenario and those actually detected around galaxies. We find that the density law proposed by Burkert reproduces the halo rotation curves, with halo central densities ( ρ 0 ∼1–4×10 −24 g cm −3 ) and core radii (r 0 ∼5–15 kpc) scaling as ρ 0 ∝ r 0 −2/3 .