Sep 2006: Submillimeter Polarimetry of Sagittarius A*
My thesis on the submillimeter properties of Sgr A* and the
Submillimeter Array polarimeter is available here. I have now moved to the University of
Chicago, where I am a Jansky Fellow and a KICP Fellow.
May 2004: First ever ground-based observations in the 1.3 THz atmospheric window!
On the morning of May 27 the RLT made the
first observations of a spectral line through the 1.3 THz
atmospheric window. The J=11-10 transition of CO at 1.26 THz was
observed in M17, along with two lower transitions (9-8 and
7-6). These three lines reside in three different atmospheric
windows; only the lowest of these (the 850 GHz window) is available for
observations at other telescopes.
Supra-terahertz windows such as these are astronomically
interesting because they provide access to emission from many
ions and molecules not available at other frequencies, as well
as new transitions of well-studied species. An example is the
1.37 THz ground-state transition of
H2D+. This moleculular ion traces the
chemical reactions responsible for complex molecule formation
occuring deep within cold molecular clouds. The only strong
transition of this molecule available at other sites (at 372
GHz) has a lower-state energy of 60 K, far too high to be
strongly excited in cold clouds.