Complex Organic Molecules from Carbon Stars to Planetary Nebulae

Wednesday, February 01, 2017 - 3:30pm to 4:30pm PST
Greg Sloan
N232, Room 103
Event Type: 

Polycyclic aromatic hydrocarbons, or PAHs, have proven to be the best candidate to explain the strong infrared emission features that appear wherever a hot radiation field impinges on a dust cloud with carbon-rich grains, from nearby planetary nebulae to high-redshift starburst galaxies.  We see the PAHs as the dust is being destroyed, but what does the carbon-rich material look like before that happens? Spectroscopic observations from the Spitzer Space Telescope reveal more fragile materials composed of mixtures of aromatic and aliphatic hydrocarbons.  Focusing on the evolution of the dust from carbon stars to planetary nebulae gives us new insights about the forms that carbon-rich dust can take.  These clues are helping us solve mysteries like the unidentified 21-um feature seen in objects part way along this evolutionary path and fullerenes seen in young planetary nebulae.

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