HI4PI: a full-sky H i survey based on EBHIS and GASS⋆
1 Argelander-Institut für Astronomie (AIfA), University of Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
2 Max-Planck-Institut für Radioastronomie (MPIfR), Auf dem Hügel 69, 53121 Bonn, Germany
3 Department of Physics and Astronomy, University of Alabama, PO Box 870324, Tuscaloosa, AL, 35487-0324, USA
4 National Radio Astronomy Observatory, PO Box 2, Green Bank, WV, 24944, USA
5 CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710, Australia
6 Steward Observatory, University of Arizona, Tucson, AZ 85721, USA
7 E. A. Milne Centre for Astrophysics, University of Hull, Hull, HU6 7RX, UK
8 Tartu Observatory, 61602 Tõravere, Tartumaa, Estonia
9 International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
10 Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia
11 Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006, Australia
12 Graduate School of Science and Engineering, Kagoshima university, 1-21-35 Korimoto, 890-0065 Kagoshima, Japan
13 Institute of Space and Astronautical Science, Japan Aerospace Exploring Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 252-5210, Japan
14 SKA Organization, Jodrell Bank Observatory, Lower Withington, Macclesfield, Cheshire SK11 9DL, UK
15 Department of Physics and Astronomy, West Virginia University, PO Box 6315, Morgantown, WV 26506, USA
16 ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Australia
Received: 24 June 2016
Accepted: 7 September 2016
Context. Measurement of the Galactic neutral atomic hydrogen (H i) column density, NH i, and brightness temperatures, TB, is of high scientific value for a broad range of astrophysical disciplines. In the past two decades, one of the most-used legacy H i datasets has been the Leiden/Argentine/Bonn Survey (LAB).
Aims. We release the H i 4π survey (HI4PI), an all-sky database of Galactic H i, which supersedes the LAB survey.
Methods. The HI4PI survey is based on data from the recently completed first coverage of the Effelsberg-Bonn H i Survey (EBHIS) and from the third revision of the Galactic All-Sky Survey (GASS). EBHIS and GASS share similar angular resolution and match well in sensitivity. Combined, they are ideally suited to be a successor to LAB.
Results. The new HI4PI survey outperforms the LAB in angular resolution (ϑFWHM = 16́́.2) and sensitivity (σrms = 43 mK). Moreover, it has full spatial sampling and thus overcomes a major drawback of LAB, which severely undersamples the sky. We publish all-sky column density maps of the neutral atomic hydrogen in the Milky Way, along with full spectroscopic data, in several map projections including HEALPix.
Key words: surveys / ISM: atoms / techniques: spectroscopic
HI4PI datasets are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (188.8.131.52) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/594/A116
© ESO, 2016