A Search for Sgr A* at 8.8$\mu$m
Session 22 -- Galactic Structure; Galactic Center
Display presentation, Monday, 9, 1995, 9:20am - 6:30pm

## [22.14] A Search for Sgr A* at 8.8$\mu$m

Susan R. Stolovy (Cornell University), Thomas Hayward (Cornell University), Terry Herter (Cornell University)

We present a deep continuum map of the central parsec of the Galaxy at 8.8 $\mu$m obtained with SpectroCam-10 at Palomar Observatory in June and July 1994 with 0.8" spatial resolution. These observations were conducted in order to search for a point source at the position of Sgr A*. The infrared position of Sgr A* was determined by registering the infrared and radio positions of the supergiant IRS 7 and then offsetting by the relative radio positions of IRS 7 and Sgr A*.

The predicted flux from a thin accretion disk around a supermassive black hole at the position of Sgr A* is 19 mJy at 8.8 $\mu$m based on the detection of a near infrared source at K$\approx$12. \footnote{Close, L., McCarthy, D., and Melia, F. ApJ. 1994, in press.} This infrared wavelength was chosen in order to maximize the ratio of expected flux to background dust continuum, which dominates the point source sensitivity rather than the noise level. We discuss the results of various methods employed in an attempt to detect a point source in the region. A point-like source was detected 1.5" to the southwest of Sgr A*; however, we estimate our absolute positioning to be correct to better than 0.5", so it is unlikely that this source is coincident with Sgr A*. We also detected a tail'' of continuum emission extending northward of IRS 7. This tail was previously observed in the radio continuum \footnote{Yusef-Zadeh, F. and Melia, F. 1992, ApJ 385, L41.} and is thought to be a cometary feature created by strong stellar winds originating from the IRS16 cluster.