The most familiar products of modern astronomy research are the breathtaking images produced by several spectacular, ambitious, and often general-purpose space-based satellite missions that have reshaped our view of the Universe. Equally important to actually understanding the workings of specific objects is the laborious, detailed study using ever-improved instrumentation on ground-based optical telescopes. Spectroscopic studies, comparing light output from astrophysical sources at different wavelengths, and recognizing the characteristic patterns emitted by specific atoms and molecules that emit in the same way as those components do here on Earth, is particularly powerful. The investigators on this project aim to build a sensitive instrument dedicated to observations of one particular spectral transition that is key to a number of interesting puzzles facing modern astrophysical research, including the behavior of the material that is seen to form a halo around distant galaxies.
The spectral line targeted by the instrument being built is the H-alpha line, and the instrument takes its name from that line and the principal science interest, galactic halos: CHaS, the Circumgalactic H-alpha Spectrograph. Kinematics of gas in the circumgalactic medium of galaxies in the nearby universe will measure the distribution of infalling and outflowing gas within the central 50-100 kpc of a galaxy's halo, and will establish a new technique for testing the modes of accretion and outflow in galaxies across cosmic time.
This project will contribute solidly to the training of the next generation of instrumentation scientists. A novel approach to outreach will also be explored: making simplified versions of the Integral Field Unit available to amateur astronomers, exploiting and building upon a long-standing synergy between amateur and professional astronomers.
Funding for this project is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.
