Is dark matter present in NGC4736? An iterative spectral method for finding mass distribution in spiral galaxies
Abstract
An iterative method for reconstructing mass distribution in spiral galaxies using a thin disk approximation is developed. As an example, the method is applied to galaxy NGC 4736; its rotation curve does not allow one to employ a model with a massive spherical halo. We find a global mass distribution in this galaxy (without non-baryonic dark matter) that agrees perfectly with the high resolution rotation curve of the galaxy. This mass distribution is consistent with the -band luminosity profile with the mean mass-to-light ratio , and also agrees with the amount of hydrogen observed in the outermost regions of the galaxy. We predict the total mass of the galaxy to be only . It is very close to the value predicted by the modified gravity models and much less than the currently accepted value of (with of the mass in a dark matter halo).
Keywords
Cite
@article{arxiv.astro-ph/0611113,
title = {Is dark matter present in NGC4736? An iterative spectral method for finding mass distribution in spiral galaxies},
author = {Joanna Jalocha and Lukasz Bratek and Marek Kutschera},
journal= {arXiv preprint arXiv:astro-ph/0611113},
year = {2009}
}
Comments
in v2 version: 1) changed the reference luminosities of the Sun in different bands - this affects mass-to-light ratio, giving more reliable 1.2 in the I-band, 2) found typos corrected, 3) corrected references to literature, figures and equations 4) text permutations + language corrections, accepted for publication in ApJ, May 2008