HIPASS
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The H I Parkes All Sky Survey (HIPASS) is a large survey for neutral atomic hydrogen (H I).[1] Most of the data was taken between 1997 and 2002 using CSIRO's 64 m Parkes Telescope. HIPASS covered 71% of the sky and identified more than 5000 galaxies; the major galaxy catalogs are: the "HIPASS Bright Galaxy Catalog" (HIPASS BGC),[2] the southern HIPASS catalog (HICAT),[3] and the northern HIPASS catalog (NHICAT)[4] Discoveries include over 5000 galaxies (incl. several new galaxies), the Leading Arm of the Magellanic Stream and a few gas clouds devoid of stars.
Southern Sky observations
HIPASS covers a velocity range of −1,280 to 12,700 km/s. It was the first blind HI survey to cover the entire southern sky and the northern sky up to +25°. Technical overview, calibration and imaging (Barnes et al. 2001).
Observations of the southern sky started in February 1997, and were completed in March 2000, consisting of 23,020 eight-degree scans of each of 9 minutes duration. HIPASS scanned the entire southern sky five times. The southern HIPASS galaxy catalog (HICAT)[3] contains 4315 HI sources.
Northern Sky observations
Northern HIPASS extended the survey into the northern sky. The entire Virgo Cluster region was observed in Northern HIPASS. NHICAT,[4] the catalogue of the northern extension of HIPASS contains 1,002 H I sources.
CHIPASS
Archival data from HIPASS and the HI Zone of Avoidance (HIZOA) survey were reprocessed to make a new 20cm confusion-limited continuum map of the sky south of declination +25°. Its relatively high sensitivity and resolution (compared to other single-dish surveys) and low level of artefacts has made this survey invaluable, particularly for merging with interferometric data such as WALLABY to improve the coverage of extended structure.[5]
Multibeam Receiver
Observations for HIPASS were taken using the Parkes 21-cm Multibeam Receiver.[6] The instrument consists of a focal-plane array of 13 individual receivers arranged in a hexagonal pattern.[6] Built in a collaboration between numerous institutions, it was funded by the Australian Research Council (ARC) and the Australia Telescope National Facility (ATNF) to undertake the HIPASS and ZOA surveys.
