ar X iv : a st ro - p h / 98 11 34 8 v 1 2 1 N ov 1 99 8 SHARC 350 μ m Mapping of the Galactic Center from the Caltech Submillimeter Observatory

Using the 20-pixel camera SHARC, we have surveyed the 350 µm emission from a 60 ′ by 12 ′ region in the Galactic center. A comparable region has been observed at 800 µm by Lis & Carlstrom (1994); the SHARC map has better spatial resolution and sensitivity to extended emission, however. This paper introduces several features not visible in prior maps of dust emission. We have detected a 10+ pc band of emission peaking at l = −0.14 • , b = +0.02 • , which is probably associated with the 'negative velocity arc' observed in 13 CO (Bally et al. 1988). We suggest an association of a rounded 350 µm feature near the Radio Arc with an expanding shell observed in CS (Tsuboi, Ukita, & Handa 1997). Faint emission at the same Galactic longitude as the Dust Ridge (Lis & Carl-strom 1994) but at opposite latitude is visible as well as a compact source at the base of a thermal radio filament at negative Galactic latitude. Diffuse dust emission within a few arcminutes of the Sgr D core is detected for the first time. 350 µm sources are associated with both H 2 O masers in Sgr D, but only one out of four OH masers (Mehringer et al. 1998). The mean 350 µm/800 µm flux ratio for the Galactic center is approximately 17 (β ∼ 2.0) over the map but is higher (β ∼ 2.5) in parts of the Dust Ridge and lower in Sgr B2 (N).