Astrophys. J., 524, 612-622 (1999/October-3)
New galaxies discovered in the first blind H I survey of the Centaurus A group.
BANKS G.D., DISNEY M.J., KNEZEK P.M., JERJEN H., BARNES D.G., BHATAL R., DE BLOK W.J.G., BOYCE P.J., EKERS R.D., FREEMAN K.C., GIBSON B.K., HENNING P.A., KILBORN V., KORIBALSKI B., KRAAN-KORTEWEG R.C., MALIN D.F., MINCHIN R.F., MOULD J.R., OOSTERLOO T., PRICE R.M., PUTMAN M.E., RYDER S.D., SADLER E.M., STAVELEY-SMITH L., STEWART I., STOOTMAN F., VAILE R.A., WEBSTER R.L. and WRIGHT A.E.
Abstract (from CDS):
We have commenced a 21 cm survey of the entire southern sky (δ<0°, -1200 km.s–1<v☉<12,700 km.s–1) that is ``blind'', i.e., unbiased by previous optical information. In the present paper we report on the results of a pilot project that is based on data from this all-sky survey. The project was carried out on an area of 600 deg2 centered on the nearby Centaurus A (Cen A) group of galaxies at a mean velocity of v☉∼500 km.s–1. This was recently the subject of a separate and thorough optical survey. We found 10 new group members to add to 21 galaxies already known in the Cen A group: five of these are previously uncataloged galaxies, while five were previously catalogued but not known to be associated with the group. Most of the new members have H I masses close to our survey limit of 107 M☉ at the assumed group distance of 3.5 Mpc. The new detection with the largest H I mass is ESO 174-G?001 with M_HI_=2.1x108 M☉. Prior to our survey this galaxy was an uncertain optical identification because of high Galactic extinction. We found optical counterparts for all the H I detections, most of them intrinsically very faint (MB>-13.0), low surface brightness dwarf galaxies with H I profile line-widths suggestive of dynamics dominated by dark matter. The new group members add approximately 6% to the H I mass of the group and 4% to its light. The H I mass function, derived from all the known group galaxies in the interval 107 M☉<M_HI_<109 M☉, has a faint-end slope of 1.30±0.15, allowing us to rule out a slope of 1.7 at 95% confidence. Even if the number in the lowest mass bin is increased by 50%, the slope only increases to 1.45±0.15.
galaxies: clusters: individual (Centaurus A) - Galaxies: Distances and Redshifts - Galaxies: ISM - Radio Lines: Galaxies - Surveys
Table 1: [K99b] HIPASS JHHMM+DD N=5, 3 are new.
View the reference in ADS
To bookmark this query, right click on this link: simbad:1999ApJ...524..612B and select 'bookmark this link' or equivalent in the popup menu