Mapping the Milky Way via 21cm Hydrogen Emissions

For strange quantum reasons, the electron in a hydrogen atom can very rarely flip spins and emit a photon at 1.4204 GHZ. These emissions are extremely rare, occurring once every \(10^7\) or so years. Luckily, there is lots of hydrogen in space, so these emissions are a staple in radio astronomy due to their prevalence and long, hard-to-distort wavelengths.

For my experimental physics class, one of my projects studied these emissions, using the radio telescope atop MIT's building 54. Using frequency shifts, I was able to work out the location and velocities of emitting sources, reconstructing a map of the Milky Way Galaxy. My results gave a good first-order approximation of the distribution of stellar clusters in the Milky Way and correctly observed our galaxy's spiral arm structure.

My project report can be found here and the accompanying presentation can be found here.