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We have recently carried out the first wide-field hydrogen Paschen-alpha line imaging survey of the Galactic Center (GC), using the NICMOS instrument aboard the Hubble Space Telescope. The survey maps out a region of 2253 pc^2 around the central supermassive black hole (Sgr A*) in the 1.87 and 1.90 Micron narrow bands with a spatial resolution of 0.01 pc at a distance of 8 kpc. Here we present an overview of the observations, data reduction, preliminary results, and potential scientific implications, as well as a description of the rationale and design of the survey. We have produced mosaic maps of the Paschen-alpha line and continuum emission, giving an unprecedentedly high resolution and high sensitivity panoramic view of stars and photo-ionized gas in the nuclear environment of the Galaxy. We detect a significant number of previously undetected stars with Paschen-alpha in emission. They are most likely massive stars with strong winds, as confirmed by our initial follow-up spectroscopic observations. About half of the newly detected massive stars are found outside the known clusters (Arches, Quintuplet, and Central). Many previously known diffuse thermal features are now resolved into arrays of intriguingly fine linear filaments indicating a profound role of magnetic fields in sculpting the gas. The bright spiral-like Paschen-alpha emission around Sgr A* is seen to be well confined within the known dusty torus. In the directions roughly perpendicular to it, we further detect faint, diffuse Paschen-alpha emission features, which, like earlier radio images, suggest an outflow from the structure. In addition, we detect various compact Paschen-alpha nebulae, probably tracing the accretion and/or ejection of stars at various evolutionary stages.
Our HST/NICMOS Pa survey of the Galactic center (GC) provides a uniform, panoramic, high-resolution map of stars and ionized diffuse gas in the central 416 arcmin^2 of the Galaxy. This survey was carried out with 144 HST orbits using two narrow-band
The Galactic Center contains some of the most extreme conditions for star formation in our Galaxy as well as many other phenomena that are unique to this region. Given our relative proximity to the Galactic Center, we are able to study details of phy
We present preliminary results of our hst Pa$alpha$ survey of the Galactic Center (gc), which maps the central 0.65$times$0.25 degrees around Sgr A*. This survey provides us with a more complete inventory of massive stars within the gc, compared to p
We present a survey of atomic hydrogen HI) emission in the direction of the Galactic Center conducted with the CSIRO Australia Telescope Compact Array (ATCA). The survey covers the area -5 deg < l < +5, -5 deg < b <+5 deg over the velocity range -309
We report the discovery of a widespread population of collisionally excited methanol J = 4_{-1} to 3$_0 E sources at 36.2 GHz from the inner 66x18 (160x43 pc) of the Galactic center. This spectral feature was imaged with a spectral resolution of ~16.