Jet Phenomena in the Solar Atmosphere with Rotational

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Jet Phenomena in the Solar Atmosphere with
Rotational Eruption or Spinning
Motion Observation associated with Our MHD
numerical Simulations
2004?4?21?
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Jets associated with Rotating Eruption or
Spinning Motion
Observations

• Alexander and Fletcher, 1999, Solar Phys., 190,
  167
• Pike and MASON, 1998, Solar Phys., 182, 333

• Kurokawa et al. 1987, Solar Phys., 108, 251
• Canfield et al. 1996, Apj, 464, 1016

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28 May 1998 two-sided
19 Aug 1998 one-sided anemone with roration
Movie
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Anemone type
Two-sided Loop Type
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19 Aug 1998 025016 UT NOAA AR8299 at the
west limb one-sided anemone with roration
No SXT data (Night)
Plasma outflow lasting 16 minutes, originated
in a small loop system Produced another jet some
7 hours Prior to the main jet there is evidence
for sporadic ejection of material from the same
region Anemone type jets described by Shimojo et
al. 1996 in that the plasma is ejected along a
single direction from a basal system of loops
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pre
Main and post
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Pre-jetting phase
Ten minutes prior to the main phase blobs
ejected along what will be the main Jet cannel
blob ejection interval 2-3 min distrinctive
black and white striations exists
Loop system (footpoint) exists, bright the
throughout event
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Main phase
Main 025025 start small Ha flare detected at
Learmonth Solar Observatory The main flaring
phase is exemplified by a large enhancement very
quickly (within 2min) a bright arcade is
formed jet traveling at 150-200 km/s
Alternating dark and white bands, suggesting
motion along a twisted structure This pattern is
interrupted the data gap (025520-030018)
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Main phase (continue)
When data resumes, a pair of jet is visible The
apparent bifurcation of this jet is interesting
(movie shows clearly) The divergence of
bifurcation is not constant but changes,
suggesting a Dynamic response to the rapid
transport of twist (untwisting?) along the field
(Canfield et al. 1996), or the development of an
instability (such as Kelvin-Helmholtz)
Post jet and anemone disappear,
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Yokoyama and Shibata (1995, 1996)
Cool and Hot plasma acceleration
Cool anemone type cool plasma is ejected along
the ambient field by the Sling-shot effect this
may be observed as an Ha surge (Canfield et al.
1996)
TRACE 171 and 1216 (contour)
1MK and 100000K
The Lya jet is very similar to that observed In
the EUV expelled at the same time Start off
along the same trajectory An important
difference is noticeable, however, The jets are
not co-spatial over their entire length. Two
jets lie on adjacent fluxtubes and That these
fluxtubes diverge at some distance From the
original point. This is consistent with model.
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28 May 1998 184158 UT NOAA AR 8227, it was
approaching the disk center two-sided
The plasma outflow lasting 16 minutes Several
EUV jets were observed between 27 May 1200 ---
29 May 1200 From the same region.
This jet has the basic structure of the two-sided
loop type jets (Shimojo et al. 1996)
Away from a central location in two directions,
roughly anti-parallel to each other One
direction apparently corresponds to upwards into
the oblique open field while the other is in the
opposite direction towards the strong magnetic
field of the nearby sunspot.
Pre-jet phase 1820 --- 1830 Main phase
1841 --- 1857
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Pre-phase
This pre-jet activity is comprised of at last two
small events each displaying The two-sided loop
morphology.
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The major brightening started around 1841 and
lasting 16 min Initially we see a small pair of
bright EUV loops which extend southwards
Towards the sunspot and northwards Towards the
open field region The southward jet remains
essentially Unchanged throughout the event
Suggesting that the jet is being Constrained by
the strong field region Of the sunspot.
Jet moving at 250km/s
A movie shows the dynamic nature of the activity
with the magnetic fluxtubes sloshing around as
the plasma is ejected, suggesting that as the jet
passes The local gas pressure is comparable to
the magnetic pressure and the jet can Perturb the
field lines
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TRACE (184916) and SXT (184907, white
contour) (184451, black contour)
Both X-ray jet and EUV one are Co-spatial,
involving the same set Of nested field lines (if
not the same Field lines) An interesting note is
the time of maximum Extent of the jet in X-rays
precedes that in EUV by 5 min. Delays in the peak
emission Of hot and cool plasma are not
uncommon (Schmieder et al. 1994) with delays of
3-4 Min. This is similar delay although this
Occurs mainly in the outer reaches of the
jet. We interpret this as a continuous jet
(rather Than a single island) in which the
temperature Decreased over time while the
velocity remains Fairly constant. In this case,
the later phases of EUV emission are enhanced by
the cooling of The earlier, hotter jet material.
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Discussions
The observed intermittent ejection of plasma
would represent multiple Tearing? (-? Tanuma)
Rotation and untwisting (Shibata and Uchida
1986) One of the characteristics of the Shibata
and Uchida model is that the jet consists Of a
hot core and cool sheath embedded in a helical
magnetic field. This may explain the travel
pattern observed in the running difference
images for The 19 August (figures 2 and 3) both
in the pre-flare and post-flare state.
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The twist has apparent clearing out (030016
UT) as the jet begins to bifurcate. It is
unclear how this removal of twist actually
progressed, due to a 5-min gap In TRACE data.
However, the bifurcation of the jet structure is
clearly evident Some 10 min after the flare
peak. Bifurcation of plasma jets in astrophysical
bodies is not uncommon, although perhaps Rare in
the solar case. Ford et al. (1986) observed Ha
jet emanating from spiral galaxy NGC 4258, the
morphology of which suggests the presence of two
double-sided jets which braid around each other
before bifurcating at the ends. Such
observations are Supported by simulations which
demonstrate that bifurcations can result from
the nonlinear dependent (cf., Hardee et al.
1995). The observation of the bifurcation of
Plasma jets in the solar atmosphere may be a
consequence of high spatial and temporal
Resolution of TRACE.