THE BRIGHTEST OBSERVED EMISSION LINE FROM MOST NORMAL STAR-FORMING GALAXIES IS THE 158 MICRON LINE ARISING FROM SINGLY-IONIZED CARBON (ALSO KNOWN AS C+ OR CII). IN FACT ASTRONOMERS HAVE RECENTLY BEGUN USING THE BRIGHT EMISSION LINE TO DETECT AND CHARACTERIZE GALAXIES IN THE FURTHERMOST REACHES OF THE UNIVERSE USING THE NEW ATACAMA LARGE MILLIMETER ARRAY IN CHILE. IT IS THUS IMPERATIVE THAT WE HAVE THE TOOLS TO FULLY UTILIZE THIS EMISSION LINE AS AN INDICATOR OF STAR FORMATION RATE A PRIMARY PARAMETER BY WHICH GALAXIES AND THEIR CONSTITUENT STAR-FORMING REGIONS ARE CHARACTERIZED. THERE ARE TWO MAIN CHALLENGES TO UTILIZING THE [CII] 158 MICRON LINE AS A STAR FORMATION RATE INDICATOR. FIRST ADVANCES IN LONG-WAVELENGTH ASTRONOMICAL INSTRUMENTATION HAVE ONLY RECENTLY ENABLED ITS DETECTION IN STATISTICALLY-SIGNIFICANT SAMPLES OF GALAXIES. SECOND IT IS BOTH A BLESSING AND A CURSE THAT SINGLY-IONIZED CARBON CAN BE CREATED IN BOTH STAR-FORMING REGIONS (IONIZED HII REGIONS) AND IN NON-STAR FORMING REGIONS (NEUTRAL PHOTO-DISSOCIATION REGIONS). FOR [CII] EMISSION TO ACCURATELY TRACE STAR FORMATION WE MUST FIND AN OBSERVATIONALLY-CONVENIENT WAY IN WHICH TO REMOVE ITS NON-STARFORMING CONTRIBUTIONS. SUCH A CALIBRATION WOULD DIRECTLY LINK [CII] 158 MICRON EMISSION WITH THE EMISSION FROM YOUNG HOT STARS THAT ARE THE TRADITIONAL TRACERS OF A GALAXY'S STAR FORMATION RATE. WE PROPOSE TO ACCOMPLISH THIS CALIBRATION BY LEVERAGING A LARGE SUITE OF OPTICAL AND INFRARED DATA FROM A RECENT SPACE-BASED SURVEY OF NEARBY STAR-FORMING GALAXIES. WITH THIS NEW CALIBRATION THE DOOR WILL BE THROWN WIDE OPEN TO MAKING DETAILED COMPARISONS BETWEEN PRESENT-DAY GALAXIES AND THOSE RECENTLY DISCOVERED AT THE EARLIEST EPOCHS OF THE UNIVERSE A KEY ROUTE TO UNDERSTANDING GALAXY EVOLUTION.
$135,000FY2020National Aeronautics and Space AdministrationNASA
University Of Wyoming, Laramie WY