18-cm VLA observations of OH towards the Galactic Centre: Absorption and emission in the four ground-state OH lines
2003 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 403, 1011-1021 p.Article in journal (Refereed) Published
The OH distribution in the Sgr A Complex has been observed in the 1612-, 1665-, 1667- and 1720-MHz OH transitions with the Very Large Array (VLA) in BnA configuration. Maps are presented with a channel velocity resolution of about 9 km s -1 and with angular resolutions of . Some clear results are highlighted here, such as absorption from the Circumnuclear Disk (CND) and the OH-Streamer inside the CND near Sgr , strong absorption towards most of the eastern and western parts of the Sgr A East shell, lack of absorption towards both Sgr A West and the compact H II-regions to the east of Sgr A East, and double-lobed structure of the High Negative Velocity Gas (HNVG) oriented northeast and southwest of Sgr , and finally compact, point-like maser emission in all four transitions, in particular a 1720-MHz maser at -132 km s -1 in the CND as counterpart to a 1720-MHz maser at +132 km s -1 in the CND.
Place, publisher, year, edition, pages
2003. Vol. 403, 1011-1021 p.
Astronomy, Astrophysics and Cosmology
Research subject Astronomy
IdentifiersURN: urn:nbn:se:su:diva-122685DOI: 10.1051/0004-6361:20030309OAI: oai:DiVA.org:su-122685DiVA: diva2:868097