From Spitzer to Herschel: Predictions for Debris Disk Gas Emissions
First Author:
Yanqin Wu
Email: wu AT astro.utoronto.ca
Univ. of Toronto
50 St. George Street
Toronto, ON M5S 3H4, Canada
Coauthors:
Kyryl, Zagorovsky, Univ. of Toronto
Alexis, Brandeker, Stockholm Observatory
Abstract
Several studies have established that there are trace amount of gas in dusty debris disks. This gas is likely not primordial, but arise from dust grains. The very environment of this gas -- next to a bright star and embedded among dusty particles -- can heat it up to high temperatures, mostly through photoelectrons knocked out from dust grains. For debris disks around early type stars (A-F type), the gas mostly radiates its heat via infrared atomic cooling lines like OI 63 micron, CII 157 micron lines. We calculate the thermal, ionization and excitation balances of this trace gas. For beta Pic like debris disks, the strongest infrared cooling lines have luminosities of order 10-7 solar luminosities and are detectable by Herschel. This then allows us to study the chemical composition of the trace gas -- and by inferrence, the chemical make-up of the extra-solar Kuiper belts.
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