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Detailed Analysis of Near-IR Water (H2O) Emission in Comet C/2014 Q2 (LOVEJOY) with the GIANO/TNG SpectrographWe observed the Oort cloud comet C/2014 Q2 (Lovejoy) on 2015 January 31 and February 1 and 2 at a heliocentric distance of 1.3 au and geocentric distance of 0.8 au during its approach to the Sun. Comet Lovejoy was observed with GIANO, the near-infrared high-resolution spectrograph mounted at the Nasmyth-A focus of the TNG (Telescopio Nazionale Galileo) telescope in La Palma, Canary Islands, Spain. We detected strong emissions of radical CN and water, along with many emission features of unidentified origin, across the 1-2.5 micron region. Spectral lines from eight ro-vibrational bands of H2O were detected, six of them for the first time. We quantified the water production rate [Q(H2O), (3.11+/- 0.14) x 10(exp 29)/s] by comparing the calibrated line fluxes with the Goddard full non-resonance cascade fluorescence model for H2O. The production rates of ortho-water [Q(H2O)ORTHO, (2.33+/- 0.11) x 10(exp 29)/s] and para-water [Q(H2O)PARA, (0.87+/-0.21) x 10(exp 29)/s] provide a measure of the ortho-to-para ratio (2.70+/- 0.76)). The confidence limits are not small enough to provide a critical test of the nuclear spin temperature.
Document ID
20170003774
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Faggi, S.
(Florence Univ. Italy)
Villanueva, G. L.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Mumma, M. J.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Brucato, J.R.
(Osservatorio Astrofisico Arcetri Florence, Italy)
Tozzi, G. P.
(Osservatorio Astrofisico Arcetri Florence, Italy)
Oliva, E.
(Osservatorio Astrofisico Arcetri Florence, Italy)
Massi, F.
(Osservatorio Astrofisico Arcetri Florence, Italy)
Sanna, N.
(Osservatorio Astrofisico Arcetri Florence, Italy)
Tozzi, A.
(Osservatorio Astrofisico Arcetri Florence, Italy)
Date Acquired
April 20, 2017
Publication Date
October 19, 2016
Publication Information
Publication: The Astrophysical Journal
Publisher: IOP Publishing
Volume: 830
Issue: 2
ISSN: 0004-637X
e-ISSN: 1538-4357
Subject Category
Lunar And Planetary Science And Exploration
Report/Patent Number
GSFC-E-DAA-TN40285
Distribution Limits
Public
Copyright
Other

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