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| Titel |
Herschel and IRAM-30m Observations of Comet C/2012 S1 (ISON) at 4.5 AU from the Sun |
| VerfasserIn |
Laurence O'Rourke, Dominique Bockelee-Morvan, Nicolas Biver, Bruno Altieri, David Teyssier, Laurent Jorda, Vincent Debout, Colin Snodgrass, Michael Küppers, Michael A'Hearn, Thomas Müller, Anthony Farnham |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250114166
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| Publikation (Nr.) |
 EGU/EGU2015-14470.pdf |
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| Zusammenfassung |
| The sungrazer comet C/2012 S1 (ISON) (perihelion at $r_h$ = 0.0125 AU from the Sun) was bright and active when discovered in September 2012 at 6.3 AU from the Sun. Our goal was to characterize the distant gaseous and dust activity of this comet, inbound, from observations of H2O, CO and the dust coma in the far-infrared and submillimeter domains. We report observations undertaken with the Herschel Space Observatory (Pilbratt et al, 2010) on 8 \& 13 March 2013 ($r_h$ = 4.54--4.47AU) and with the 30m telescope of Institut de Radioastronomie Millim\'{e}trique (IRAM) in March and April 2013 ($r_h$ = 4.45--4.18 AU). The HIFI instrument aboard Herschel was used to observe the H$_{2}$O $1_{10}-1_{01}$ line at 557 GHz, whereas images of the dust coma at 70~$\mu$m and 160~$\mu$m were acquired with the PACS instrument. Spectra acquired at the IRAM 30m telescope cover the CO $J$(2--1) line at 230.5 GHz. The spectral observations were analysed with excitation and radiative transfer models (Biver et al., 2007). A model of dust thermal emission taking into account a range of dust sizes is used to analyse the PACS maps, equivalent to that used in Bockel\'{e}e-Morvan et al., 2010. While H$_{2}$O was not detected in our 8 March 2013 observation, we derive a sensitive 3$\sigma$ upper limit of $Q_{\rm H_2O}$ $ |
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