The Origin of Daughter Species in Cometary Comae: Results from Observations of Comets 103P/Hartley and C/2009 P1 Garradd
Abstract
The origin of daughter species in cometary comae has been a subject of much debate. Some cases, like that of OH and H2O, are well understood, while most cases are not. In order for the origin of daughter species to be properly understood, coincident observations of both daughter species and their candidate parent molecules are needed to constrain the prevailing coma photochemistry. We present analysis of near simultaneous observations of candidate parent molecules and their daughters in comets 103P/Hartley and C/2009 P1 Garradd using a combination of infrared and optical spectroscopy with the goal of more firmly understanding the parentage of C2 and CN and using the red-to-green line ratios in OI as a probe of the relative production rates of its dominant parents, H2O, CO, and CO2. We obtained optical observations with the ARCES echelle spectrometer mounted on the Astrophysical Research Consortium 3.5-meter telescope at Apache Point Observatory located in Sunspot, New Mexico, while we obtained IR observations for Garradd with the CSHELL IR spectrometer mounted on NASA's Infrared Telescope Facility in Hawaii. We also compare our results to measurements of candidate parent species reported in the literature. Observations in the optical were conducted with sufficient time resolution and time coverage to detect modulation in the production rates and mixing ratios from rotation (Hartley) and changing heliocentric distance (Garradd). We measure how the production rates and mixing ratios vary and discuss the implications for the progeny of C2, CN, and OI in cometary comae.
- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #45
- Pub Date:
- October 2013
- Bibcode:
- 2013DPS....4550207M