J/AJ/160/282 Optical and IR spectroscopy of Europa (Trumbo+, 2020)
Endogenic and exogenic contributions to visible-wavelength spectra of Europa's
trailing hemisphere.
Trumbo S.K., Brown M.E., Hand K.P.
<Astron. J., 160, 282 (2020)>
=2020AJ....160..282T 2020AJ....160..282T
ADC_Keywords: Solar system; Planets; Spectra, optical; Spectra, infrared
Keywords: Galilean satellites ; Solar system astronomy ; Surface composition
Abstract:
The composition of Europa's trailing hemisphere reflects the combined
influences of endogenous geologic resurfacing and exogenous sulfur
radiolysis. Using spatially resolved visible-wavelength spectra of
Europa obtained with the Hubble Space Telescope, we map multiple
spectral features across the trailing hemisphere and compare their
geographies with the distributions of large-scale geology,
magnetospheric bombardment, and surface color. Based on such
comparisons, we interpret some aspects of our spectra as indicative of
purely exogenous sulfur radiolysis products and other aspects as
indicative of radiolysis products formed from a mixture of endogenous
material and magnetospheric sulfur. The spatial distributions of two
of the absorptions seen in our spectra-a widespread downturn toward
the near-UV and a distinct feature at 530nm-appear consistent with
sulfur allotropes previously suggested from ground-based
spectrophotometry. However, the geographies of two additional
features-an absorption feature at 360nm and the spectral slope at red
wavelengths-are more consistent with endogenous material that has been
altered by sulfur radiolysis. We suggest irradiated sulfate salts as
potential candidates for this material, but we are unable to identify
particular species with the available data.
Description:
We observed Europa with the Space Telescope Imaging Spectrograph
(STIS) across four Hubble Space Telescope (HST) visits in 2017. We
achieved a 300-1000nm coverage with a spectral resolution of R∼500.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig2.dat 49 1833 Representative spectrum from our HST data of the
trailing hemisphere of Europa
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See also:
J/A+A/493/1171 : Mutual phenomena Galilean satellites PHEMU03 (Arlot+, 2009)
J/A+A/532/A36 : Galilean satellites mutual events in 2009 (Zhang, 2011)
J/other/SoSyR/49.383 : Galilean satellites & Jupiter pos. (Narizhnaya, 2015)
J/other/SoSyR/50.344 : Galilean moons & Jupiter positions (Narizhnaya, 2016)
J/other/SoSyR/52.312 : Galilean moons positions (Narizhnaya+, 2018)
J/other/SoSyR/53.368 : Observations of the Galilean moons (Narizhnaya+, 2019)
Byte-by-byte Description of file: fig2.dat
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Bytes Format Units Label Explanations
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1- 24 E24.18 nm Wave [3e+02/1.1e+03] Wavelength
26- 49 E24.18 --- Refl [1.1e-1/1.1] Relative reflectance
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 18-Feb-2021