Far-Infrared Photometric Mapping of G0.18-0.04 in the Galactic Center Arc

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Session 34 -- Airbourne Astronomy
Display presentation, Tuesday, 9:30-6:30, Pauley Room

[34.18] Far-Infrared Photometric Mapping of G0.18-0.04 in the Galactic Center Arc

M.Morris (UCLA), J.A.Davidson (NASA/Ames), M.W.Werner (JPL), P.M.Harvey, D.F.Lester, B.J.Smith (U.Texas)

The linear, nonthermal filaments of the radio Arc near the Galactic center encounter a dense molecular cloud where they cross the Galactic plane (Serabyn \& G\"usten 1991). At the location of the encounter, the cloud becomes ionized and is prominent as strong, thermal radio emission, constituting G0.18-0.04 and G0.15-0.05 (Yusef-Zadeh and Morris 1987; Yusef-Zadeh, Morris, \& van Gorkom 1989). In addition, this HII region is a strong source of far-infrared radiation, indicating that a great deal of energy accompanies the ionization (Odenwald \& Fazio 1984). Using the KAO, we have mapped the dust emission from G0.18-0.04 at 50 and 100 $\mu$m. These data reveal the spatial variations of dust temperature and luminosity for comparison with existing radio continuum and molecular line maps. These comparisons can be used to assess alternative hypotheses for the ionization and the production of the luminosity: stellar photoionization versus a collisional or magnetohydrodynamic process. The "quintuplet" of near-IR sources located near G0.15-0.05 is notably weak or absent as a source of far-IR radiation. This research was supported by NASA. \vskip 0in \noindent Odenwald, S.F. \& Fazio, G.G. 1984, ApJ, 283, 601. \vskip 0in \noindent Serabyn, E. \& G\"usten, R. 1991, A\&A, 242, 376. \vskip 0in \noindent Yusef-Zadeh, F. \& Morris, M. 1987, AJ, 94, 557. \vskip 0in \noindent Yusef-Zadeh, F., Morris, M. \& van Gorkom, J. 1989, in "IAU Symp. 136: The Center of the Galaxy", ed: M. Morris, Dordrecht:Kluwer, p 275.

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