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  • A 10’ × 10’ Map Of 205 Micron [NII] In The Carina II Star-forming Nebula

    Paper ID

    6115

    author

    • Thomas E. Oberst
    • Gordon J. Stacey
    • Stephen C. Parshley
    • Thomas Nikola
    • Julia Kamenetzky
    • Andrea Loehr
    • Adiar P. Lane
    • Antony Stark

    company

    Cornell University;

    country

    United States

    year

    2007

    abstract

    We present the results of an extended ~10’ × 12’ mapping of the 205 $\mu$m $^{3}P_{1}$ $\to$ $^{3}P_{0}$ [NII] line in Carina II, an active star-forming region in the Galactic plane. The observations were performed using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) from the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) at the South Pole. Together with a companion mapping of Carina I (Oberst et al., in prep.), these observations constitute the first ever ground-based direct detection of the 205 $\mu$m [NII] line and the first detection of this line overall in more than 10 years, as first reported in Oberst et al., 2006 (which presents data from the single peak position of Carina II only). The 205 $\mu$m [NII] line is among the brightest of far-infrared and submillimeter spectral lines –- accounting for ~0.03 \% of the total Milky Way luminosity at these wavelengths --- and is a key diagnostic for galaxies. The relative line strength of 205 $\mu$m to 122 $\mu$m [NII] traces the density of ionized gas, and that of 205 $\mu$m [NII] to 158 $\mu$m [CII] traces the relative abundance of C$^{+}$ arising from ionized gas and the neutral interstellar medium (ISM). Because C$^{+}$ is the dominant coolant for much of the ISM in galaxies, these findings provide important constraints for molecular cloud and photodissociation region models. We derive these constraints here by comparing our results with prior observations of 158 $\mu$m [CII] and 122 $\mu$m [NII] from ESA’s International Space Observatory (ISO). This work extends the pioneering studies of C$^{+}$ and N$^{+}$ by NASA’s Kuiper Airborne Observatory (KAO) and Cosmic Microwave Background Explorer (COBE) Far Infrared Absolute Spectrophotometer (FIRAS), and provides reference data points for future observations, in particular those of ESA’s Herschel Space Observatory and NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA).