AAS 201st Meeting, January, 2003
Session 47. The Interstellar Medium I
Poster, Tuesday, January 7, 2003, 9:20am-6:30pm, Exhibit Hall AB

## [47.11] CO and H2 in the Diffuse Interstellar Medium

E. B. Burgh (UW-Madison), K. France, S. R. McCandliss (JHU), J. C. Howk (UCSD)

We are investigating the molecular content of the diffuse interstellar medium along sightlines to stars that have been observed by the Space Telescope Imaging Spectrograph aboard the \textit{Hubble Space Telescope} and the \textit{Far-Ultraviolet Spectroscopic Explorer}. A sample of stars was chosen from archival data originally observed as part of several snapshot surveys. Both CO and H2 have extensive absorption bands in the ultraviolet, the measurement of which allows for a direct comparison of the molecular abundances along a given line-of-sight.

The data presented here cover the diffuse ISM, i.e. AV \lesssim 1, with 0.07 \lesssim EB-V \lesssim 0.5. A preliminary analysis has been performed on a number of stars. Absorption line-shape models were used to fit the CO J''~=~0 and 1 and H2 0~\le~J''\le 4 rotational features. Correlations of CO with H2 as well as CO/H2 with EB-V and environment are investigated.

Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.