The Columbia Astrophysics Laboratory (CAL) is a joint enterprise of the Physics and Astronomy Departments. Graduate students in either department are encouraged to select advisors on the basis of interest rather than affiliation. In addition, there are at least a dozen postdoctoral researchers working in both departments.
Astrophysics research at Columbia essentially spans the entire observable electromagnetic spectrum: gamma-ray (Elena Aprile, Chuck Hailey, Reshmi Mukherjee), X-ray (Chuck Hailey, David Helfand), optical (Arlin Crotts, Jules Halpern, Laura Kay, Joe Patterson), radio (David Helfand, Jacqueline van Gorkum), and microwave (Amber Miller).
Astronomical systems of interest include: cataclysmic variables, neutron stars, black holes, galactic nuclei, gamma-ray bursts, quasars, galaxies, supernovae, the intergalactic medium, the cosmic microwave background, as well as the large-scale structure of the universe.
Searches for dark matter weakly interacting massive particles (WIMPs), both with an underground direct detection experiment (Elena Aprile) and with a space-based experiment (Chuck Hailey), are also part of the research program in particle astrophysics at Columbia.
There is also strong interaction between the experimental/observational program and the theoretical program. Please refer to the theory page and the astronomy department home page for further details.