Spectroscopic Studies of the Galactic Center Region

scientific abstract the center 10. (about 20 pc) of the milky way contains several interesting phenomena which are not found elsewhere in the galaxy. very near to the dynamical center, there is a unique nonthermal radio point source, sgr a*, which may well be a massive (10^6 m solar) black hole. small scale (1 pc) radio filaments appear to circulate about sgr a* (the minispiral). sgr a* is also enveloped by both a massive and dense stellar cluster and a rotating circumnuclear gas and dust disk (cnd). about 20 pc from sgr a*, there are several straight nonthermal radio filaments which extend about 30 pc perpendicular to the galactic plane. these nonthermal filaments appear to be linked to the galactic center by a series of thermal radio arches. enveloping (and perhaps constraining) these large scale radio structures are several massive molecular clouds. we propose to investigate the physical conditions, dynamics, energetics and ionization structure of many of these phenomena through a series of lws fabryperot and grating studies. besides being a unique and interesting source in of itself, the center of the milky way also provides a nearby prototype to study and compare to more distant spiral nuclei. observation summary our highest priority is to obtain fully sampled grating spectra over a fully sampled region enclosing the cnd and thermal arc, and nonthermal arc, over the full grating range. our map will be aligned with the cnd major axis and fully sample regions 350x1100 and 200x500 in extent. the integration time (total of 7.5 hours) was chosen to ensure detection of lines at the level of 1e15 w/m^2 over the entire band, and ten times weaker at the more sensitive wavelengths; the value is 100 times weaker than the currently known oi line in this beam. the aot was crafted to use detector lw4 on this strong source. the observations will provide information about the ionization structure (e.g. trunca [truncated!, Please see actual data for full text]