Galactic Cloud Formation
I received a grant from the NSF to work at the National Astronomy and Ionosphere Center in Arecibo, Puerto Rico, home the world's largest "stationary" radio telescope. (The center was made famous by two popular movies, "Contact" and "Golden Eye" from the James Bond franchise.) I worked with Dr. Avinash A. Deshpande studying molecular clouds, in particular W49A.
The molecular cloud W49 is the most luminous star forming region in our galaxy with a luminosity several times that of the sun. It is separated into two regions: A and B. W49A is of interest because it is an active star forming region, and therefore there exists the possibility of detecting molecular transition lines using a radio telescope. Understanding the properties of molecular clouds gives us more information and understanding of the building blocks of the universe.
Observations of the molecular cloud W49A with the NAIC Arecibo Telescope were made across the frequency range 327 MHz - 10 GHz in order to identify molecular and recombination lines. At L-band detections of the 1665.40 MHz and 1667.35 MHz masers and the 21cm HI absorption line were made. At higher frequencies, X and S-high bands, an abundance of Hydrogen and Helium recombination lines were observed including high ∆n lines never before detected such as H167η, H157ζ, and H172θ. Determining the electron temperature reveal a linear relationship with ∆n. However, inabilities to properly estimate the peak intensities of high ∆n may have produced systematic underestimations of electron temperature. Further investigation into the regimes where local thermodynamic equilibrium break-down could reveal the discrepancy in electron temperature.