Titan Airglow: FUV & EUV 2009 UVIS
Spectra of Airglow During Day,
Night & Eclipse :
JOSEPH AJELLO
JPL
MICHAEL STEVENS
NRL
ROBERT WEST
JPL
JACQUES GUSTIN
LPAP
GREG HOLSCLAW
CU
TODD BRADLEY
UCF
TITAN PROTON PLASMA (0.1 keV-4 MeV)
& SOLAR XUV GENERATES 2-level
IONOSPHERE (300-1500 KM)
-Solar XUV Excitation –Strong
Top Ionosphere
-Magnetospheric: p and O+
Plasma (Cravens et al., 2008).
N2 Cross section Analysis for Dayglow
VI (2)→UVIS (16)→Lab(e +N2 300 features)
V(z)=g(z) x w
gj (z) = F (e) x n(z) x s(e)
Dl=0.2Å
Dl=30Å
Dl=5Å
DD
ISS & UVIS OBSERVATION OF
TITAN SOLAR ECLIPSE @ 600K km
plasma + N2
FUV DARK SIDE LIMB & DISK
SPECTRA DOY110-2009 @15K km
Laboratory Result: p + N2
ELECTRON CROSS SECTIONS FOR
TITAN DAYGLOW UV EMISSION
MODEL
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sLBHPK=
0.6 A&S
(1985)
sLBH=0.7
A&S (1985)
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STEVENS ET AL., 2011
“Production of Titan’s Far ions
Ultraviolet Nitrogen Airglow”
AURIC Code Emission Cross
Sections:
N2 Carroll-Yoshino c4′—X
system,b‘-X, b-X systems
N I and N II multiplets
the N2 Lyman-Birge-Hopfield a—X
system (Young et al., 2010)
the N2 Vegard-Kaplan A—X bands
Best (S/N) Titan Dayglow UVIS
Limb Spectrum; 22June 2009: ‘800
km STARE’
–40
DEC (deg)
–42
EUV
–44
–46
–48
4
2
0
RA (deg)
–2
–4
1500
Pixel Center Ray Height (km)
One hour
EUV and
FUV image
of 15 – 4
minute
records .
1000
FUV
500
0
0
10
20
30
40
Pixel Number
50
60
AURIC MODEL FIT TO UVIS EUV
SPECTRUM AT 1000 KM
AURIC MODEL FIT TO UVIS FUV
SPECTRUM AT 1000 KM
AURIC MODEL OF FUV VERs AND
COLUMN EMISSION RATES
The FUV Dayglow Limb Spectra
of Titan
Surface to Exosphere: 13Dec04.
DARK SIDE OBSERVATION OF TITAN ON
25MARCH2008
FUV LIMB PROFILE INTENSITIES
OF 25 MARCH2009
Model fit to UVIS Dark Limb (Twilight)
EUV Spectrum from 25Mar08 with a
Regression Model - 7-Vectors)
HOW to GET a BRIGHT UV Airglow
in 2009
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BRIGHTEST LIMB
AIRGLOW 22JUNE
2009 obs[14]
SZA=53DEG, MRH =1000
km S/C ~60k KM
BRIGHTEST DISK & 2ND
LIMB 12OCT OBS[4551]
LIMB~ 1000KM
SZA~95, S/C ~175k KM
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SUMMARY OF 2009 ECLIPSE, LIMB,
BRIGHT DISK AND DARK DISK
UVIS OBSERVATIONS OF TITAN
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Solar Driven processes on Dayside and Twilight
Observed EUV and FUV Emissions during 1 of 3
Eclipses. Probably Plasma impact.
Tentative Sporadic FUV Nightglow Spectra at 0.1
Intensity level of dayglow. Probably Plasma Impact
(protons, O+, electrons).
Twilight (Terminator) Glow-Solar XUV at 90-120
deg Limb SZA ~ 0.2-0.5 Dayside Intensity.
N2 EUV (12R) /FUV (200R) dayglow structure
similar to Earth
Elvis Lives (Titan Organic
Chemistry-Biomarker! )
45 years with my Honey