Detection of the 205 μm [NII] Line from the Carina Nebula

• Main Authors: Stacey, G. J., Oberst, T. E., Loehr, A., Nikolal, T., Parshley, S. C., Tothill, N. F. H., Harnett,, J. I., Lane, A. P., Stark, A. A., Tucker, Carole
• Other Authors: Maestrini, Dr. Alain, Beaudin, Dr. Gerard
• Format: Conference Object
• Language: unknown
• Published: Kluwer Academic 2006
• Subjects: QB Astronomy; Antarctic; The Antarctic; South Pole; Antarc*; South pole
• Online Access: https://orca.cardiff.ac.uk/id/eprint/71339/

We report the first detection of the 205 micron 3P1-3P0 [NII] line from a ground based observatory using a direct detection spectrometer. The line was detected and mapped in emission from the Carina star formation region in the Galaxy using the South Pole Imaging Fabry-Perot Interfereometer (SPIFI) on the Antarctic Submillimeter Telescope and Remote Observatory AST/RO at the South Pole. The [NII] line is an important coolant for the diffuse ionized ISM, and (together with the 122 um [NII] line) is an excellent probe of gas density. The [NH] 205 micron line emission peaks at the Carina II HII region, and its strength indicates a low density (n < 30 cm-3) ionized medium. When compared with the ISO [CII] observations of this region, we find about half the [CII] line emission arises from this low density ionized gas as well. The detection of this line demonstrates the utility of Antarctic sites for THz spectroscopy.