WG4 Multi-wavelength Correlative Studies Group Members

1
WG4 Multi-wavelength Correlative StudiesGroup
Members
Marina BATTAGLIA Cristina CHIFOR Brian
DENNIS Martin FIVIAN Lyndsay FLETCHER Iain
HANNAH Hugh HUDSON Haisheng JI Joe KHAN Säm
Krucker Helen MASON Ryan MILLIGAN Manuela
TEMMERMikko VÄÄNÄNEN Lidia van DRIEL-GESZTELYI
Astrid VERONIG Alexander WARMUTH
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RHESSI WG4 SCHEDULE
Wednesday 1100 1300 RHESSI Thermal / low
energy / multi-l spectroscopy 1430 1800
Footpoints Part I Thursday 0900 1030
Coronal sources, joint with WG3 1100 1300
Footpoints Part II 1430 1600 Joint session
with WG2 Oct 28th event 1630 1800 Joint
with WG5 soft-hard-soft, number
problem, etc. Friday 0930 1100 Energetics
3
RHESSI Observations of the Iron-Line Feature

• From Fe line complex at 6.7keV, compared to
  continuum we have a handle on the Fe/H abundance
  ratio.
• How does the empirical Fe/H abundance ratio in
  flares vary with Te ?
• How do empirical correlation curves compare with
  theoretical curves calculated with coronal Fe
  abundances ?

• Survey of 30 RHESSI flares (C3 - X5)
• Fe line features observed by RHESSI at 6.7 keV
  indicate a coronal abundance of Fe
• Discrepancies could be due to instrumental
  effects,
• non-isothermality
• errors in atomic rates

CHIFOR/PHILLIPS/DENNIS
4
RHESSI Quiet Sun Offpointing

• Offpoint RHESSI from Sun to modulate QS signal
  and separate from background noise limited or
  signal ?
• 667hrs off sun (so far), 127hrs useful (20),
  63hrsltA1(9.5
• So far, have observed Quiet Sun with hot coronal
  loops in SXI/EIT

• New limits in 3-17 keV
• correlates with GOES in 3-7 keV ?QS signal
  detected?
• Fit Hot T, low EM (5-7MK, 1044cm3) or steep
  power-law (lt-7)
• Comparable limits 17-100 keV
• What will we get with more offpointing during
  Solar minimum?

HANNAH
5
PINT-of-ALE DEM

• Multi-instrument DEM
• Ten RHESSI bins from 5 12 keV
• Two GOES channels
• Markov-Chain Monte Carlo method

uncertainties (colour bars) returned by MCMC
analysis
DENNIS/LI
6
Inter-instrument calibration XSMRHESSI
XSM/RHESSI spectrum
XSM/RHESSI lightcurve 6-8kev

• XSM GOES calibrations OK
• XSM/RHESSI low E needs factors explained
• Messenger/XSM underway

VÄÄNÄNEN/DENNIS
7
Propagating Brightenings Following Filament
Eruptions
Brightenings parallel to flare ribbons were
observed with RHESSI (Grigis Benz) Survey of
brightenings associates with erupting filaments
in EIT shows many examples of brightenings along
arcade footpoints Slow speeds correspond to slow
eruptions
MASON/TRIPATHI
8
RHESSI-SOHO/CDS Observations of Chromospheric
Evaporation
Plasma velocities observed with CDS during
impulsive phase of 2 flares

• A high flux of non-thermal electrons ?
  high-velocity upflows and low-velocity downflows
  (explosive evaporation)
• A flux value an order of magnitude lower ? weaker
  upflows and no downflows (gentle evaporation)

MILLIGAN
9
Constraints from the magnetic field on HXR source
motions (17-Jan-2005 X3.8 flare)
RHESSI HXR sources occur only along certain parts
of the Ha ribbon edges Higher local reconnection
rates (factor 5-10) at these sites
HXR sources tend to avoid strongest magnetic
fields and umbrae. Almost vertical inclination of
field lines does not favour reconnection there?
Peculiar motions/spatial jumps of HXR sources?
Reconnection rises through field lines of lines
of different altitudes, with distant footpoint
locations
TEMMER
10
Reconnection rates and HXR characteristics
VERONIG
11
Correlation of FP Motion with Deposited Energy

• 2-d model, sheet of area Ar
• Ar LhLv area of reconn. region
• Correlation of Deposited Energy with Footpoint
  Separation
• a acceleration efficiency
• Smooth correlation curve ? accurate (stable)
  FP positions and fits of spectra
• Can derive the required current sheet vertical
  extent, Lv

LV ? 25 arcsec
LV ? huge
LV ? 100 arcsec
FIVIAN
12
Footpoint motions and flare shear
Red contour 30-50 keV Blue contour 3-10
keV Green contour 34GHz
The distance and velocity between the two Ha
kernels The distance between the two HXR FPs The
height of the HXR loop top source The flare
shear time profile The rate of change of flare
shear
JI
13
Coronal Sources in an occulted solar flare
20-Jul-2002
100-200keV
50-100keV
20-30keV

• Hard spectral index 3.0
• GOESRHESSI gives density estimate of
  2.2x1011cm-3.
• Column depth will collisionally stop electrons
  with 30-40keV
• How does gt 100keV emission arise?

BONE
14
Flux Spectral Index correlations in coronal
sources

• RHESSI imaging - spectroscopy finds
  soft-hard-soft behavior in the coronal source of
  several flares ? might be a feature of the
  accelerator and not a transport effect

Time evolution of spectral index and non-thermal
flux at 35 keV of coronal hard X-ray spectra
BATTAGLIA/BENZ
15
Relativistic Shock Drift Acceleration (SDA) at
the Reconnection Outflow Termination Shock (TS)

• theory fast-mode standing shock in
  reconnection outflow
• radio observations signatures of TS are
  present
• theory relativistic shock drift acceleration
  at the TS
• comparison of theory and observations
• SDA at the TS can reproduce required electron
  fluxes power

WARMUTH/MANN/AURASS
16
Moreton wave in Radio
Is the termination shock suggested by Warmuth
et al a standing shock at all?
Moreton/coronal wave seen in radio Dotted line
Edge of Ha Moreton wave
PICK
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WG 45
Flux spectral index correlation (SHS)
presentation by Grigis on a transit-time damping
model Electron total numbers, fluxes, and
predicted/observed response of atmosphere
discussion by all
Presentation by Pick on Type III bursts
associated with compressing edge of a CME new
theoretical challenge (see Stevens presentation)
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Rising Coronal X-ray Source and Erupting Filament
pos i t i on
Fe XIX Doppler velocity
SOHO/CDS slit
Flux rope
Vllt0

Vlgt0
Cooling loops
time

• RHESSI coronal source at constant distance
  beneath filament RHESSI source as result of
  interaction of upwards outflow jets with
  filament?
• CDS observations with slit above a rising
  filament magnetic field extrapolations
• ? downflows of hot plasma along flare loop legs
• Rapid motion of filament into LASCO FOV implies
  exponential growth of CMEs in the low corona

van Driel/Goff et al
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Height-time plot, low corona
Exponential growth
Height-time plot, high corona
LASCO/C2 v120 km/s
EUV flux rope v45-75 km/s
?
THE WINNER !
LASCO/C2
RHESSI source 60 km/s
TRACE
v60 km/s
New evidence for flux rope structure of an
erupting filament Linking a rising
RHESSI coronal source to the erupting filament
New evidence for exponential growth of CMEs
in the low corona - result of kink
instability? Results consistent with
down-flows of hot plasma along both loop legs.
Contour RHESSI 10-15 keV
SOHO/CDS slit
position
Fe XIX Doppler velocity
Flux rope
Vllt0

?
Vlgt0
magnetic extrapolation ? 3-D flare loop
orientation
Cooling loops
TRACE EUV image
time
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Flare energetics

• Total radiated energy in SXR (LSXR) from GOES
• Total radiated energy from hot plasma (Lhot) from
  GOES T EM.
• Total radiated energy from SORCE (Ltotal)
• CME KE from LASCO

Ltotal KECME 10 Lhot 100 LSXR
DENNIS
21
White Light Flares and Energetics
1 px 0.5 300km
Orange25-50keV BlueWL

• Very compact sources
• Correlated in time and space with HXRs at 10s of
  keV
• Provide an independent diagnostic for energy
  deposited in atmosphere
• Same order of magnitude as electron energy flux
  inferred from HXR thick target

HUDSON/FLETCHER