Final Selection

The final MHONGOOSE sample of 30 galaxies was selected from the proto-sample of 88 galaxies in two steps. In the first step, optical SINGG and DSS images were examined and galaxies that were affected by bright foreground stars were rejected.  We also rejected cases where the galaxy is too big to comfortably fit in to the MeerKAT primary beam, or where there is a very strong interaction between galaxies. These out-right rejections are given in this table

As noted before, the aim is to retain 5 galaxies in each of our 6 bins of HI mass. We stepped through each of these bins and used DSS, SINGG and WISE images to pick what was considered to be the best edge-on, the best face-on, and the best intermediate inclination galaxy in each bin.  The factors that went in to deciding which galaxy was "best" were how close they were to edge-on or face-on as judged from the images, their angular size, and distance (nearest galaxies preferred).  The remaining two galaxies in each bin were selected to cover a range of interesting properties, such as surface brightness, and the appearance of extra-planar H-alpha (while still taking into account the desired inclination ranges). 

Galaxies that were neither edge-on, face-on, nor near 60 deg inclination were given lower rankings.  A-typical galaxies, e.g., well-known AGN or galaxies with very peculiar morphology, as well as remaining cases with significant but not disabling image blemishes (e.g., bright foreground stars) were given lower priority.

Ranks beyond the first 5 in each bin were done primarily by angular size and inclination, with the atypical galaxies and blemish affected galaxies listed at the end (largest rank number).  This table and this table list the rankings, as well as notes on the galaxy morphologies and selection. 

A table with the final sample is given on this page. Note that even though this is to be considered our final sample, there is still the option to swap galaxies in and out should further characterization of galaxies (e.g., during commissioning) show that there are scientifically valid reasons to do so. Note that the Table lists 31 galaxies instead of 30 as NGC 3511 and NGC 3513 share the same MeerKAT pointing.

Further work is underway regarding the sample characterisation. This consists of retrieving and analysing archival HI data, mainly from ATCA and KAT 7. These data are available for about half of the sample. 

© Erwin de Blok 2017