Samenvatting
We present a new strategy for fitting the structure and kinematics of
the H I in edge-on galaxies using a fit to the terminal-velocity channel
maps of a H I data cube. The strategy can deal with self-absorbing H I
gas and the presence of warps. The method is first tested on a series of
models. We demonstrate that fitting optically thin models to real
galaxies will lead to an overestimation of the thickness and velocity
dispersion, and to a serious underestimation of the H I face-on column
densities. We subsequently fit both self-absorption and optically thin
models to the H I data of six edge-on galaxies. In three of these, we
have also measured the velocity dispersion. On average, 27 ± 6
per cent of the total H I mass of edge-on galaxies is hidden by
self-absorption. This implies that the H I mass, thickness and velocity
dispersion of galaxies is typically underestimated in the literature.
Originele taal-2 | English |
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Pagina's (van-tot) | 32-47 |
Aantal pagina's | 16 |
Tijdschrift | Monthly Notices of the Royal Astronomical Society |
Volume | 464 |
Nummer van het tijdschrift | 1 |
DOI's | |
Status | Published - jan.-2017 |