HIPASS

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HIPASS
Website www.atnf.csiro.au/research/multibeam/

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.

Contents

Survey

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).

Southern Sky observations

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.

Discoveries

Leading arm of Magellanic Stream

HIPASS discovered the Leading Arm of the Magellanic Stream. This is an extension of the Magellanic Stream beyond the Magellanic clouds. The existence of the Leading Arm is predicted by models of a tidal interaction between the Magellanic Clouds and the Milky Way.

HIPASS J0731-69

HIPASS J0731-69 is a cloud of gas devoid of any stars. [7] It is associated with the asymmetric spiral galaxy NGC 2442. [7] It is likely that HIPASS J0731-69 was torn loose from NGC 2442 by a companion. [7]

HIPASS J1712-64

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.

New galaxies in the Centaurus A/M83 Group

Ten new galaxies were identified in the Centaurus A/M83 Group, bringing the total (at the time) to 31 galaxies. [9]

See also

Related Research Articles

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<span class="mw-page-title-main">Tarantula Nebula</span> H II region in the constellation Dorado

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<span class="mw-page-title-main">NGC 3109</span> Galaxy in the constellation Hydra

NGC 3109 is a small barred Magellanic type spiral or irregular galaxy around 4.35 Mly away in the direction of the constellation of Hydra. NGC 3109 is believed to be tidally interacting with the dwarf elliptical galaxy Antlia Dwarf. It was discovered by John Herschel on March 24, 1835 while he was in what is now South Africa.

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<span class="mw-page-title-main">NGC 1569</span> Galaxy in the constellation Camelopardalis

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<span class="mw-page-title-main">NGC 2442 and NGC 2443</span> Spiral galaxy in the constellation Volans

NGC 2442 and NGC 2443 are two parts of a single intermediate spiral galaxy, commonly known as the Meathook Galaxy or the Cobra and Mouse. It is about 50 million light-years away in the constellation Volans. It was discovered by Sir John Herschel on December 23, 1834 during his survey of southern skies with a 18.25 inch diameter reflecting telescope from an observatory he set up in Cape Town, South Africa. Associated with this galaxy is HIPASS J0731-69, a cloud of gas devoid of any stars. It is likely that the cloud was torn loose from NGC 2442 by a companion.

<span class="mw-page-title-main">NGC 1566</span> Galaxy in the constellation Dorado

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<span class="mw-page-title-main">NGC 346</span> Open cluster in the constellation Tucana

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<span class="mw-page-title-main">NGC 1808</span> Galaxy in the constellation Columba

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NGC 290 is an open cluster of stars in the southern constellation of Tucana. This cluster was discovered September 5, 1826, by Scottish astronomer James Dunlop. It lies some 200,000 light years away from the Sun in the Small Magellanic Cloud galaxy. The cluster is an estimated 30–63 million years old and is around 65 light years across.

<span class="mw-page-title-main">NGC 4449</span> Galaxy in the constellation Canes Venatici

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<span class="mw-page-title-main">Dorado Group</span> Galaxy cluster in the constellation Dorado

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<span class="mw-page-title-main">NGC 24</span> Galaxy in the constellation Sculptor

NGC 24 is a spiral galaxy in the southern constellation of Sculptor, about 23.8 megalight-years distant from the Milky Way. It was discovered by British astronomer William Herschel in 1785, and measures some 40,000 light-years across. The general shape of this galaxy is specified by its morphological classification of SA(s)c, which indicates it is an unbarred spiral with no ring-like structure and moderate to loosely-wound spiral arms. This galaxy is positioned in the vicinity of the Sculptor Group, but is actually a background object that is more than three times as distant. It may form a pair with another background galaxy, NGC 45.

<span class="mw-page-title-main">NGC 2552</span> Magellanic Spiral galaxy in the constellation Lynx

NGC 2552 is a Magellanic spiral galaxy located some 22 million light years away. It can be found in constellation of Lynx. This is a type of unbarred dwarf galaxy, usually with a single spiral arm. It is inclined by 41° to the line of sight from the Earth along a position angle of 229°. The measured velocity dispersion of the stars in NGC 2552 is relatively low—a mere 19 ± 2 km/s. This galaxy forms part of a loose triplet that includes NGC 2541 and NGC 2500, which together belong to the NGC 2841 group.

<span class="mw-page-title-main">NGC 2397</span> Galaxy in the constellation Volans

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<span class="mw-page-title-main">NGC 299</span> Open star cluster in the constellation Tucana

NGC 299 is an open cluster of stars in the main body of the Small Magellanic Cloud – a nearby dwarf galaxy. It is located in the southern constellation of Tucana, just under 200,000 light years distant from the Sun. The cluster was discovered on August 12, 1834, by English astronomer John Herschel.

<span class="mw-page-title-main">NGC 376</span> Globular cluster located in the constellation Tucana

NGC 376 is a young open cluster of stars in the southern constellation of Tucana. It was discovered on September 2, 1826, by Scottish astronomer James Dunlop. Dreyer, a Danish/British astronomer, described it as a "globular cluster, bright, small, round." It is irregular in form, with a central spike.

<span class="mw-page-title-main">NGC 3256</span> Peculiar galaxy in the constellation Vela

NGC 3256 is a peculiar galaxy formed from the collision of two separate galaxies in the constellation of Vela. NGC 3256 is located about 100 million light-years away and belongs to the Hydra–Centaurus Supercluster complex. NGC 3256 provides a nearby template for studying the properties of young star clusters in tidal tails. The system hides a double nucleus and a tangle of dust lanes in the central region. The telltale signs of the collision are two extended luminous tails swirling out from the galaxy. The tails are studded with a particularly high density of star clusters. NGC 3256 is the most luminous galaxy in the infrared spectrum located within z 0.01 from Earth.

<span class="mw-page-title-main">NGC 3175</span> Galaxy in the constellation Antlia

NGC 3175 is a spiral galaxy located in the far eastern part of the southern constellation of Antlia at an approximate distance of 54 million light-years. NGC 3175 was discovered on March 30, 1835 by English astronomer John Herschel, whose notes described it as, "considerably bright, large, much extended NE-SW, very gradually little brighter middle". This galaxy is the namesake of the NGC 3175 group of galaxies, which includes the spiral galaxy NGC 3137.

References

  1. "HI Parkes All Sky Survey (homepage)".
  2. Koribalski, B. S.; et al. (2004). "HIPASS Bright Galaxy Catalog". The Astronomical Journal. 128 (1): 16. arXiv: astro-ph/0404436 . Bibcode:2004AJ....128...16K. doi:10.1086/421744. S2CID   16229767.
  3. 1 2 Meyer, M. J.; et al. (2004). "Southern HIPASS catalog". Monthly Notices of the Royal Astronomical Society. 350 (4): 1195. arXiv: astro-ph/0406384 . Bibcode:2004MNRAS.350.1195M. doi: 10.1111/j.1365-2966.2004.07710.x . S2CID   10336076.
  4. 1 2 Wong, O. I.; et al. (2006). "Northern HIPASS Catalog". Monthly Notices of the Royal Astronomical Society. 371 (4): 1855–1864. arXiv: astro-ph/0607491 . Bibcode:2006MNRAS.371.1855W. doi: 10.1111/j.1365-2966.2006.10846.x . S2CID   22014830.
  5. Calabretta, Mark R.; Staveley-Smith, Lister; Barnes, David G. (2014). "A New 1.4 GHz Radio Continuum Map of the Sky South of Declination +25°". Publications of the Astronomical Society of Australia. 31: e007. arXiv: 1310.2414 . Bibcode:2014PASA...31....7C. doi: 10.1017/pasa.2013.36 . ISSN   1323-3580.
  6. 1 2 "Multibeam Receiver". Archived from the original on 2000-08-19.
  7. 1 2 3 Ryder, S.D.; et al. (July 2001). "HIPASS Detection of an Intergalactic Gas Cloud in the NGC 2442 Group". The Astrophysical Journal. 555 (1): 232–239. arXiv: astro-ph/0103099 . Bibcode:2001ApJ...555..232R. doi:10.1086/321453. S2CID   14455875.
  8. 1 2 Kilborn V.A.; et al. (September 2002). "An Extragalactic H I Cloud with No Optical Counterpart?". The Astronomical Journal. 120 (3): 1342. arXiv: astro-ph/0005267 . Bibcode:2000AJ....120.1342K. doi:10.1086/301542. S2CID   11668655.
  9. Banks D.G.; et al. (October 1999). "New Galaxies Discovered in the First Blind H I Survey of the Centaurus A Group". The Astrophysical Journal. 524 (2): 612–622. arXiv: astro-ph/9906146 . Bibcode:1999ApJ...524..612B. doi:10.1086/307854. S2CID   118921426.