The ``HIPASS Bright Galaxy Catalog''

B. Koribalski (ATNF) + HIPASS/ZOA Teams

(updated: 3 - August - 2001)


Procedure and selection criteria:

The following steps were carried out to obtain the final catalog.

  1. Virginia Kilborn's program gfinder was run on 388 luthered and edge-masked HIPASS cubes, covering the whole southern sky, over all 1024 channels (i.e. -1281 to 12741 km/s), with an HI peak flux cutoff of 60 mJy/beam.
    (March 2000: newg_finder.pl -i cube -c 0.06 -b 5 -d 0 ).
    This procedure generated a list of 245230 source candidates.

    Note that the finder is optimised to find point sources and rejects detections which appear in one channel only. The large number of candidates is mostly due to artifacts generated in areas of strong continuum flux, mostly the Galactic Plane, (causing a baseline ripple), the HI emission in our Galaxy, and lots of interference (1408 MHz birdie, GPS etc.). The candidate list also contains a large number of hydrogen recombination line detections. Many galaxies, especially those with double or multi-horn profiles, also have several entries.

  2. From that list a sample with the following parameters was extracted (using BK's fortran program gcutoff2) :

  3. Multiple entries were removed (diff(pos) < 6 arcmin and diff(vsys) < 200 km/s; using VK's perl program compare.pl ).

  4. For each candidate a cube number and velocity range, both for the HI emission analysis and the baseline fit, was calculated based on the systemic velocity and velocity width given by the finder (BK's program cubeno). All candidate spectra were displayed with the miriad program mbspect and classified as "good", "bad" or "check". The latter positions were inspected in the original cubes and assigned a "good" or "bad" or other appropriate label (e.g. "HVC", "LArm") according to their apparent nature.

  5. All sources in the remaining sample were inspected with the miriad program mbspect, based on the gfinder parameter output (RA, DEC, vsys, w50), and non-galaxy entries (recombination lines, interference, etc.) were removed. At the same time the start and end velocities for fitting the source HI spectrum as well as the range of continuum channels to fit a baseline were adjusted.

  6. Optical identifications were obtained from NED

    Catalog name HIPASS
    HI peak flux
    Number of
    candidates
    -multiples Number of galaxies:
    all # new + HVCs
    HIP > 120 2191 1130 618 # 26 + 5
    ADD 100 - 120 1375 896 258 # 25 + 10
    ADE 90 - 100 1342 1060 175 # 10 + 10
    ADF 80 - 90 2478 1980 177 # 23 + 3
    ADG 70 - 80 5094 4091 not done yet
    ADH 60 - 70 9316 7713 not done yet

  7. The following sub-samples were searched in addition:

    Catalog name Selection(*) Number of
    candidates
    -multiples Number of galaxies
    all # new + HVCs
    NAR / HVC velocity width 10-30 km/s 691 613 20 # 4 + 19
    NEG / HVC systemic velocity <-350 km/s 307 248 ---- + 9
    * only one selection criterion was changed each time, the rest remained as in step (2)

  8. The following galaxies were added to this sample:
    Catalog name Selection Number of
    galaxies
    HI peak flux
    > 80 mJy/beam
    NEDsystemic velocity <350 km/s 85 24?
    HIZSS latitude |b| < 5 degr
    int. HI flux > 4 Jy km/s
    110 51? (31 new)

  9. Using mbspect preliminary HI parameters were obtained for all objects using the gfinder positions and assuming they are point sources.

  10. Accurate galaxy center positions and an estimate of the source diameter were then obtained by using the miriad program imfit on moment-0 maps produced using the recorded start and end velocity information of each source in the sample (by Stuart Ryder; currently complete for HIP, ADD, ADE galaxies).

  11. Divide sample into point sources and extended sources (not done yet).

  12. mbspect needs to be run again on all extended sources.


CSIRO - Australian Science, Australia's Future
Bärbel Koribalski (bkoribal @ atnf.csiro.au)