ESPM-13 Curdt 1
Helicity in spicules andexplosive events
Werner Curdt 1), Hui Tian 2)
1) Max-Planck-Institut für Sonnensystemforschung2) High Altitude Observatory
ESPM-13 Curdt 2
Helicity in spicules andexplosive events
Outline:
Motivation EE properties Observational details The problem with EE Helicity in small-scale phenomena Helicity in EE & consequences Conclusion
ESPM-13 Curdt 3
„Explosive Events“:
Doppler motion: ± 50 ... 150 km/s duration 60 ... 200 s size 1500 ... 2500 km burst rate several minutes -1
birth rate 2500 per second temperature transition region lines
Dere 1984
Innes 1997Chae 1998Madjarska 2002Ning 2004Teriaca 2004...
„Explosive Events“:
Doppler motion: ± 50 ... 150 km/s duration 60 ... 200 s size 1500 ... 2500 km burst rate several minutes -1
birth rate 2500 per second temperature transition region lines
model
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AR 11124 onNov 16, 2010
SUMER slit onSDO images
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lambda / nm
spec
tralr
adia
nce
Si III Lyman-α
●S
I
●S
I
●S
I
●S
I
●S
I ●S
I ●S
I
ESPM-13 Curdt 6
- rapid „switch on“- no accelaration- Dopplerflow ± 40 km/s- continues over 4 minutes- double-peaked lightcurve- τ=2πr / v ≈ 150 s
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ESPM-13 Curdt 7
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- rapid „switch on“- no accelaration- Dopplerflow ± 35 km/s- continues over 4 minutes- double-peaked lightcurve- τ=2πr / v ≈ 160 s
ESPM-13 Curdt 8
... it is difficult to explain the lack of apparent motion of such high-velocity events ...
Dere et al. 1984
... the event ... does not continueto spread in size ... and seems to stay very localized
Innes et al. 1997
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O V 629 Åv = -30 ... + 30 km/s CDS tornados (Pike 1998)
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φ = 0° 30° 45° 90°
ESPM-13 Curdt 12
Observation on Nov 19, 2010 model, φ = 45°
S I
S I
φ = 45°
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slit of 0.3“dispersed emission of EEinclinedby several pixels !
+40 km/s -40 km/s
Rompolt 1975:Spectral features to be expectedfrom rotational ... motions in fine solar structures
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vlos = 40 km/svp = 56 km/sr =1000 kmac = v2 / r = 3.2 km/s2 ≈ 10 a
The centripetal acceleration exceeds the solar gravityby an order of magnitude !
Pasachoff 1968
ESPM-13 Curdt 15
helicity in CMEs
helicity in coronal bright points and X-ray jets(Tian 2008, Kamio 2009, Liu 2011)
31 out of 79 EUVI jets show helical motion (Nisticó 2009)
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Kamio et al. 2010
XRT
STEREO 304
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Concluding remark:
(1) case study vsstatistical result
(2) IRIS 10 faster(3) source of helicity ?(4) photospheric nature ?
Curdt & Tian 2011