IRAM-30m Molecular Submm Surveys of Two Very Different Comets: C/2011 L4 (PanSTARRS) and C/2012 F6 (Lemmon)
Abstract
The two bright comets of the spring of 2013, C/2011 L4 (Pan-STARRS) and C/2012 F6 (Lemmon) were observed on 14-18 March and 5-8 April with the IRAM-30m radiotelescope in Spain. Despite adverse observing conditions we conducted wide frequency surveys (85-93, 166-170, 210-272 GHz) of the two comets using the EMIR receivers and high resolution FTS spectrometer. The wide instantaneous frequency coverage (12-16 GHz dual polarization) enables the coverage of many lines of the same molecular species, making the detection faster. We detected HCN, HNC, CS, HCO+, CH3OH, HC3N, HNCO in comet PanSTARRS and HCN, HNC, HC3N, CH3CN, HNCO, CH3OH, H2CO, H2S, CS, C34S, SO, OCS, H2CS, HCO+ and HDO in comet Lemmon. We present derived production rates and their time evolution. Relative molecular abundances will be discussed in the context of our taxonomic study of Oort-cloud comets [1,2,3]. Comet Lemmon appears intrinsically much more gaseous than comet PanSTARRS and relatively rich in volatiles. [1] Biver et al. (2002), Earth, Moon and Planets 90, 32 [2] Crovisier et al. (2009), Earth, Moon Planet 105, 267 [3] Biver et al. (2011), A&A 528, A142
- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #45
- Pub Date:
- October 2013
- Bibcode:
- 2013DPS....4550203B