CSOLOGO1 CSOLOGO2Flare activities towards the Galactic Center Sagittarius A*.  

Using the SHARCII camera at the CSO, a team of astronomers captured a submillimeter-wavelength flare from the environment of the supermassive black hole at the center of our Milky Way galaxy.  Known as Sagittarius A*, the medium surrounding the black hole has been studied for decades at radio wavelengths, where electrons moving near the speed of light through magnetic fields in the vicinity of the black hole emit synchrotron radiation.  More recently, it has been possible to study the higher energy electrons which emit at the shorter submillimeter (450 micron and 850 micron) wavelengths in which the CSO specializes.  Yusef-Zadeh et al. report a dramatic flare at 850 microns -- one of the first few measured -- in which Sagittarius A* increased in brightness by 40% within one hour.  The same flare was also seen by the Hubble Space Telescope, observing at the same time as the CSO at a shorter wavelength (2micron).  The results are to appear in the Astrophysical Journal in 2006(astro-ph 0510787).


sgrastar_image1

Figure 1. Dust images at submillimeter wavelengths towards Sgr A* (Dowell et al. 2005).



sgrastar_image1

Figure 2. Dramatic flare activity of Sgr A* captured at the submillimeter wavelength (850micron)  (Dowell et al 2005).



sgrastar_flare_diagram

Figure 3. Light curves of the flare of Sgr A* simultaneously captured at two different wavelength (near infrared (1.6-1.9 micron) and  850 micron)(Yusef-Zadeh et al 2006).