| Website | www |
|---|---|
TheH I Parkes All Sky Survey (HIPASS) is a largesurvey forneutral atomic hydrogen (H I).[1] Most of the data was taken between 1997 and 2002 using CSIRO's 64 mParkes 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 theMagellanic Stream and a few gas clouds devoid ofstars.
HIPASS covers avelocity range of −1,280 to 12,700 km/s. It was the first blind HI survey to cover the entiresouthern 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 HIPASS extended the survey into thenorthern sky. The entireVirgo Cluster region was observed in Northern HIPASS. NHICAT,[4] the catalogue of the northern extension of HIPASS contains 1,002 H I sources.
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 ofdeclination +25°. Its relatively highsensitivity andresolution (compared to other single-dish surveys) and low level of artefacts has made this survey invaluable, particularly for merging with interferometric data such asWALLABY to improve the coverage of extended structure.[5]
Observations for HIPASS were taken using the Parkes 21-cm Multibeam Receiver.[6] The instrument consists of afocal-plane array of 13 individual receivers arranged in a hexagonal pattern.[6] Built in a collaboration between numerous institutions, it was funded by theAustralian Research Council (ARC) and theAustralia Telescope National Facility (ATNF) to undertake the HIPASS and ZOA surveys.
HIPASS discovered the Leading Arm of the Magellanic Stream. This is an extension of the Magellanic Stream beyond theMagellanic clouds. The existence of the Leading Arm is predicted by models of atidal interaction between the Magellanic Clouds and the Milky Way.
HIPASS J0731-69 is a cloud of gas devoid of any stars.[7] It is associated with the asymmetric spiral galaxyNGC 2442.[7] It is likely that HIPASS J0731-69 was torn loose from NGC 2442 by a companion.[7]
HIPASS J1712-64 is an isolated extragalactic cloud of neutral hydrogen with no associated stars.[8] The cloud is a binary system and is not dense enough to form stars.[8] HIPASS J1712-64 was probably ejected during an interaction between the Magellanic clouds and the Milky way.
Ten new galaxies were identified in theCentaurus A/M83 Group, bringing the total (at the time) to 31 galaxies.[9]
| Photographic | |
|---|---|
| Infra-red | |
| Radio | |
| Spectroscopic |
|
