Detection of volatiles sublimating from 67P/Churyumov-Gerasimenko coma particles using ROSINA/COPS. Part I. ram gauge. (arXiv:2012.01495v2 [astro-ph.EP] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Pestoni_B/0/1/0/all/0/1">Boris Pestoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Altwegg_K/0/1/0/all/0/1">Kathrin Altwegg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Balsiger_H/0/1/0/all/0/1">Hans Balsiger</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hanni_N/0/1/0/all/0/1">Nora Hänni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rubin_M/0/1/0/all/0/1">Martin Rubin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schroeder_I/0/1/0/all/0/1">Isaac Schroeder</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schuhmann_M/0/1/0/all/0/1">Markus Schuhmann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wampfler_S/0/1/0/all/0/1">Susanne Wampfler</a>
The ESA Rosetta mission has allowed an extensive in-situ study of comet
67P/Churyumov-Gerasimenko. In measurements performed by the ram gauge of the
on-board COmet Pressure Sensor (COPS), features have been observed that deviate
from the nominal ram gauge signal. These are attributable to the sublimation of
the volatile fraction of cometary icy particles containing volatiles and
refractories.
The objective of this work is the investigation of the volatile content of
icy particles that entered the COPS ram gauge.
The ram gauge measurements are inspected for features that we associate to
the sublimation of the volatile component of cometary particles impacting the
instrument. All sublimation features with high enough signal to noise ratio are
modelled by fitting one or more exponential decay functions. The parameters of
these fits are used to categorise different compositions of the sublimating
component.
From features attributable to ice sublimation, we infer the detection of 73
icy particles containing volatiles. 25 detections have enough volatile content
for an in-depth study. From the values of the exponential decay constants, we
classified the 25 inferred icy particles into three types, interpreted as
different volatile compositions, possibly further complicated by different
morphologies. Available data do not give indication as to which molecules
compose the different types. Nevertheless, we can estimate the total volume of
volatiles, expressed as the diameter of an equivalent sphere of water (density
of 1 g cm$^{-3}$). This was found to be on the order of hundreds of nanometres.
The ESA Rosetta mission has allowed an extensive in-situ study of comet
67P/Churyumov-Gerasimenko. In measurements performed by the ram gauge of the
on-board COmet Pressure Sensor (COPS), features have been observed that deviate
from the nominal ram gauge signal. These are attributable to the sublimation of
the volatile fraction of cometary icy particles containing volatiles and
refractories.
The objective of this work is the investigation of the volatile content of
icy particles that entered the COPS ram gauge.
The ram gauge measurements are inspected for features that we associate to
the sublimation of the volatile component of cometary particles impacting the
instrument. All sublimation features with high enough signal to noise ratio are
modelled by fitting one or more exponential decay functions. The parameters of
these fits are used to categorise different compositions of the sublimating
component.
From features attributable to ice sublimation, we infer the detection of 73
icy particles containing volatiles. 25 detections have enough volatile content
for an in-depth study. From the values of the exponential decay constants, we
classified the 25 inferred icy particles into three types, interpreted as
different volatile compositions, possibly further complicated by different
morphologies. Available data do not give indication as to which molecules
compose the different types. Nevertheless, we can estimate the total volume of
volatiles, expressed as the diameter of an equivalent sphere of water (density
of 1 g cm$^{-3}$). This was found to be on the order of hundreds of nanometres.
http://arxiv.org/icons/sfx.gif
