J/A+A/704/A160 Comet 67P O5+ and O6+ fluxes (Martin+, 2025)
High charge-state solar wind ions interacting with comet
67P Churyumov-Gerasimenko. Observations and comet activity estimates.
Martin M., Canu-Blot R., Stenberg Wieser G., Nilsson H., Wieser M.,
Wedlund C.S., Rubin M.
<Astron. Astrophys. 704, A160 (2025)>
=2025A&A...704A.160M 2025A&A...704A.160M (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Comets ; Spectroscopy ; Optical
Keywords: plasmas - instrumentation: detectors - solar wind - comets: general -
comets: individual: 67P/Churyumov-Gerasimenko
Abstract:
Solar wind interacts with atmospheres of planets, moons and comets.
One of the important interaction processes is charge-exchange. High
charge-state heavy ions in the solar wind are prone to charge-exchange
with typical atmospheric constituents due to their large cross
sections. These processes are important for remote observations of
comets through X-ray emissions.
We survey the ESA/Rosetta data for in-situ observations of
multiply-charged oxygen ions and estimate the neutral outgassing rate
of comet 67P/Churyumov-Gerasimenko through the fluxes of heavy ions
such as O6+ and O5+. Methods. We use data from the Ion Composition
Analyzer on board the Rosetta spacecraft to obtain oxygen ion fluxes.
The expected signal is weak and therefore we apply careful data
filtering. We then adapt a pre-existing model to calculate the
outgassing rate of the comet.
We find that multiply-charged oxygen ions are mostly found post
perihelion. The estimated outgassing rate is
QthO=1.87x1028Rh-5.00[s-1] with Rh the heliocentric distance.
The outgassing estimates agree well with estimates from previous
studies based on observations of helium ions. We extend these previous
studies with a completely independent data set, with coverage until
the end of the mission and by taking the varying neutral gas
composition into account. The ratio of oxygen-to-helium fluxes also
matches previous measurements. Our comparison to ROSINA neutral gas
measurements shows that heavy solar wind ions, such as oxygen, can be
used to retrieve the neutral gas activity of the comet, when direct
neutral gas observations are not available.
Description:
Contains a table with all the observation periods (∼15 minutes
intervals for 1 observation, between 1-5 full energy scan) as well as
the fluxes of O6+ and O5+.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
obsflux.dat 79 90 Observed fluxes of O6+ and O5+
--------------------------------------------------------------------------------
See also:
J/A+A/548/A12 : 67P/Churyumov-Gerasimenko R-band light curve (Lowry+, 2012)
J/MNRAS/462/S138 : Robotic view of 67P perihelion (Snodgrass+, 2016)
J/A+A/603/A87 : Local production rates of 67P/CG from MIRO (Marshall+, 2017)
J/A+A/520/A92 : Global plasma parameter simulation of Comet 67P
(Gortsas+, 2010)
J/A+A/527/A113 : 67P/Churyumov-Gerasimenko R-band light curve
(Tubiana+, 2011)
J/A+A/647/A119 : Comet 67P/Churyumov-Gerasimenko FUV aurora
(Stephenson+, 2021)
J/MNRAS/500/4901 : Deuterated methanol in comet 67P/C-G (Drozdovskaya+, 2021)
J/A+A/672/A136 : 67P/Churyumov-Gerasimenko volatile exposures
(Fornasier+, 2023)
J/A+A/672/A170 : Comet 67P/Churyumov-Gerasimenko radio spectra (Biver+, 2023)
Byte-by-byte Description of file: obsflux.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.12 d StartTime Start time of the observation (1)
20- 37 F18.12 d EndTime End time of the observation (1)
39- 58 F20.16 1/(s.sr.cm+2.eV) FO5+ Particle flux of O5+
(in #/(s.sr.cm^2.eV) units)
60- 79 F20.16 1/(s.sr.cm+2.eV) FO6+ Particle flux of O6+
(in #/(s.sr.cm^2.eV) units)
--------------------------------------------------------------------------------
Note (1): Start and end times are matplotlib dates object use
matplotlib.dates.num2dates to convert it to human readable dates.
--------------------------------------------------------------------------------
Acknowledgements:
Maxime Martin, maxime.martin147(at)gmail.com
(End) Patricia Vannier [CDS] 03-Nov-2025