Sandhya M Rao

  • Research Professor
317 Allen Hall


My research involves studying the evolution of galaxies as traced by quasar absorption lines. Specifically, I am studying the properties of damped Lyman alpha (DLA) systems, which are the strongest absorption lines of hydrogen seen in quasar spectra. The DLAs contain the bulk of the observable neutral gas in the Universe, and since neutral gas cools to molecular gas which eventually forms stars, DLAs are important probes of galaxy evolution. We design surveys to search for these rare DLAs with the Hubble Space Telescope, and study their properties using HST as well as large ground-based telescopes such as the WIYN, the 4m, and the MDM on Kitt Peak in Arizona, the IRTF and Gemini telescope on Mauna Kea in Hawaii, and the VLT in Chile. We have also mined quasar spectra in the Sloan Digital Sky Survey to search for strong metal absorption lines that are proxies for DLAs. This helps us follow the evolution of neutral gas through a large fraction of the age of the Universe.


Selected Publications