The COBE-FIRAS Far-IR Spectral Survey of the Galaxy
Session 114 -- Multi-Phase Interstellar Medium
Display presentation, Saturday, January 15, 9:30-6:45, Salons I/II Room (Crystal Gateway)

## [114.09] The COBE-FIRAS Far-IR Spectral Survey of the Galaxy

C.L. Bennett, J.C. Mather (NASA/GSFC), D.J. Fixsen (ARC), G. Hinshaw (HSTX), E.L. Wright (UCLA)

The FIRAS instrument on the COBE satellite has conducted an unbiased survey of the far-infrared emission from our Galaxy. The first results of this survey were reported by Wright et al. (1991). We report the results of new analyses of this spectral survey, which includes emission lines from 158 $\mu$m C$^+$, 122 $\mu$m and 205 $\mu$m N$^+$, 370 $\mu$m and 609 $\mu$m C$^0$, and CO J=2-1 through 5-4. We report the morphological distribution along the galactic plane ($b=0^\circ$) of the spectral line emission, and the high galactic latitude intensities of the C$^+$ and 205 $\mu$m N$^+$ emission. The 205 $\mu$m line of N$^+$ generally follows the 158 $\mu$m C$^+$ line distributions, but the intensities scale as $I({\rm N}^+\;205 \;\mu{\rm m})\propto I({\rm C}^+\;158\;\mu{\rm m})^{1.5}$. The C$^+$ is closely correlated with neutral atomic hydrogen, and the C$^+$ cooling rate is presented. We conclude that this emission arises almost entirely from the Cold Neutral Medium. The high galactic latitude intensity of the 205 $\mu$m fine structure transition from N$^+$, also reported, arises almost entirely from the Warm Ionized Medium.

The COBE Project is supported by the NASA Office of Space Sciences and Applications, and managed by the Goddard Space Flight Center.