Single-Dish Observations of H$^{13}$CO$^+$ and SiO in the Circumnuclear Molecular Disk of the Galactic Center
Session 50 -- The Milky Way
Display presentation, Thursday, June 15, 1995, 9:20am - 4:00pm

## [50.03] Single-Dish Observations of H$^{13}$CO$^+$ and SiO in the Circumnuclear Molecular Disk of the Galactic Center

Leslie A. Sherman (Vassar College), Jonathan M. Marr (Haverford College)

We will present the results from observations with the 37-meter telescope at the Haystack Observatory of H$^{13}$CO$^+$ (J=1$\rightarrow$0) and SiO (J=2$\rightarrow$1, v=0) in two particular clumps of the circumnuclear molecular disk at the Galactic Center. The H$^{13}$CO$^+$ intensity is used in conjuction with previous data of H$^{12}$CO$^+$ and HCN (Marr, Wright, and Backer 1993) to estimate the abundance ratio of HCO$^+$ to HCN in one clump. Marr, Wright, and Backer (1993) had found this abundance ratio to be exceptionally low throughout the disk.

In the brightest clump of the circumnuclear disk, where enhanced emission by shocked H$_2$ is also seen (DePoy, Gatley, and McLean 1989), we obtain an upper limit to the opacity of SiO, which when compared to that of HCN (Marr, Wright, and Backer 1993) is a good indicator of shocked regions (Ziurys et al. 1989).

\bigskip \bigskip We are grateful to the William Keck foundation for providing primary support for this research, including summer salary for LES, through the Keck Northeast Astronomy Consortium.