Relative strengths of known diffuse interstellar bands. From http://en.wikipedia.org/wiki/File:Diffuse_Interstellar_Bands.gif.
We had a great talk today from Dr. Gail Zasowski of Johns Hopkins University Astronomy. She talked about mysterious spectral features called diffuse interstellar bands (or DIBS).
Illustrated at left, DIBs are spectral absorption features that pop up when astronomers point their telescopes in almost any direction in the sky. The DIBs are probably created by some type of molecule (or molecules) that abounds throughout our galaxy, but astronomers and astrochemists haven’t figure out what it is yet, even after decades of work.
Dr. Zasowski described how the DIBs could be identified in the vast collection of spectra from the APOGEE project and then used to map structure in the Milky Way. It goes to show that, just because we don’t know what exactly we’re looking at, it doesn’t mean astronomers can’t use the information to learn about the universe.