Open AccessOn the apparent coupling of neutral hydrogen and dark matter in spiral galaxies
Author(s) -
Hoekstra H.,
Van Albada T. S.,
Sancisi R.
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.1365-8711.2001.04214.x
Subject(s) - physics , astrophysics , galaxy rotation curve , spiral galaxy , dark matter , galaxy , elliptical galaxy , spiral (railway) , astronomy , galaxy formation and evolution , mathematical analysis , mathematics
We have studied a mass model for spiral galaxies in which the dark matter surface density is a scaled version of the observed H i surface density. Applying this mass model to a sample of 24 spiral galaxies with reliable rotation curves, one obtains good fits for most galaxies. The scaling factors cluster around 7, after correction for the presence of primordial helium. For several cases, however, different, often larger, values are found. For galaxies that cannot be fitted well, the discrepancy occurs at large radii and results from a fairly rapid decline of the H i surface density in the outermost regions. Because of such imperfections and in view of possible selection effects, it is not possible to conclude here that there is a real coupling between H i and dark matter in spiral galaxies.