1. A Panoramic HST Infrared View of the Galactic Center Q. D. Wang, H. Dong, D. Calzetti (UMass), A. Cotera (SETI), S. Stolovy, M. Muno, J. Mauerhan, (Caltech/IPAC/JPL), C. C. Lang (U. of Iowa), M. R. Morris, E. A. Mills (UCLA), G. Schneider (U. Arizona) Q. Daniel Wang (UMass; wqd@astro.umass.edu) Please see also the posters by Hui (415.01) and Mills (416.10) et al. today. More information can be obtained at www.astro.umass.edu/~wqd/gcps/web/www.astro.umass.edu/~wqd/gcps/web/

2. HST/NICMOS 1.90  m Map of the Galactic Center Distance to the Galactic center: 26,000 light-year Resolution: 0.025 light-year (0.2”) 144 HST orbits, taken between Feb and June, 2008  144X4X4=2304 images for each of the two wavelength filters 39’ (300 light-year) 15’ (115 light-year) Q. Daniel Wang (UMass; wqd@astro.umass.edu) Sgr A* Arches cluster Quintuplet cluster  l l  b b Foreground dusty clouds

3. HST/NICMOS 1.87  m Map of the Galactic Center The 1.9  m filter is sensitive to the stellar continuum emission. The 1.87  m filter covers the P  line. Subtracting the 1.9  m map from the 1.87  m map adaptively.  A net P  line emission map (see the poster by Dong et al.; 415.01). Q. Daniel Wang (UMass; wqd@astro.umass.edu) Sgr A* Arches cluster Quintuplet cluster Arched HII filaments Sickle HII region

4. Net Pα Map of the Galactic Center Why do we need the HST? Excellent imaging stability Only observable from the space Little background due to the Earth’s warm atmosphere Q. Daniel Wang (UMass; wqd@astro.umass.edu)

5. Map of Pα + stellar continuum: Preliminary Results ~0.6 million stars, resolving ~65% of the total stellar light observed. ~300 stars show enhanced Pα emission (green dots). ~2/3 of them are located outside the three known clusters. 13 have been followed up spectroscopically, confirming that they are indeed massive stars  a new population of massive stars. Ionized gas features resolved into arrays of organized linear filaments  strong local magnetic fields. Q. Daniel Wang (UMass; wqd@astro.umass.edu)

6. Sickle HII Region Red: radio continuum Green: P  Blue: 1.9  m Detailed structure of ionized gas pillars sculpted by the intense radiation and wind from the Quintuplet cluster. But magnetic field may also play a critical role (see the poster by Mills et al.; 416.10). Q. Daniel Wang (UMass; wqd@astro.umass.edu)

7. Red: 8  m (IRAC) Green: P  Blue: 1.9  m Ionized gas around the supermassive black hole is confined to a spiral embedded in a circumnuclear dusty torus. Evidence for ionized gas outflows from this torus. Nuclear Spiral/Torus Q. Daniel Wang (UMass; wqd@astro.umass.edu) Sgr A*

8. Detailed views of inidividual compact HII regions Q. Daniel Wang (UMass; wqd@astro.umass.edu)

9. Summery We have produced an unprecedented high-resolution infrared panorama of the Galactic center. Initial results: –Discovery of a new population of very massive stars in relative isolation and with strong winds. –Fine filamentary structures of ionized diffuse gas indicating profound influence of local strong magnetic field. –Detections of compact nebulae, tracing various stages of massive star evolution We aim to understand the formation modes of massive stars and their interplay with the extreme environment in galactic nuclei. Q. Daniel Wang (UMass; wqd@astro.umass.edu) Please see posters by Dong (415.01) and Mills (416.10) et al. today More information available at www.astro.umass.edu/~wqd/gcps/web/ www.astro.umass.edu/~wqd/gcps/web/ The research is supported by NASA/STScI

10. GC2009 Workshop: The window to nuclear environment of disk galaxies Place: Shanghai Dates: October 19-23 –a 4.5 full-day science program, including “min-debates” focusing on key unsolved issues. –A half-day tour (a small ancient town, the famous Bund, a banquet dinner on a boat touring the Huang-Pu river). http://www.shao.ac.cn/gc2009/ Q. Daniel Wang (UMass; wqd@astro.umass.edu)

11. Topics physics of the accretion flow around SMBHs, including the mechanism of the flaring activity in Sgr A* high energy phenomena -- gamma rays and cosmic rays star formation in circumnuclear regions and the distinction from "normal" star formation environment stellar dynamics around SMBHs population and distribution of compact objects around SMBHs stellar and gaseous contents in the nuclear and circumnuclear regions and the fueling of SMBHs SMBH feedback effects on the nuclear and circumnuclear environment interplay between stars and the interstellar medium magnetic field and its role in regulating the gas dynamics fundamental physics at the Galactic Center (e.g., dark matter annihilation and GR effects) formation and evolution of SMBHs Q. Daniel Wang (Umass) wqd@astro.umass.edu)