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WG4 Multi-wavelength Correlative Studies Group 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 TEMMER Mikko VÄÄNÄNEN Lidia van DRIEL-GESZTELYI

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wg4 multi wavelength correlative studies group members
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

slide2

RHESSI WG4 – SCHEDULE

Wednesday

11:00 – 13:00 RHESSI Thermal / low energy / multi-l spectroscopy

14:30 – 18:00 Footpoints Part I

Thursday

09:00 – 10:30 Coronal sources, joint with WG3

11:00 – 13:00 Footpoints Part II

14:30 – 16:00 Joint session with WG2 – Oct 28th event

16:30 – 18:00 Joint with WG5 – soft-hard-soft, number problem, etc.

Friday

09:30 – 11:00 Energetics

slide3

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

rhessi quiet sun offpointing
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%), 63hrs<A1(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 (<-7)
  • Comparable limits 17-100 keV
  • What will we get with more offpointing during Solar minimum?

HANNAH

pint of ale dem

DEM  exp(-T/T0)

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

inter instrument calibration xsm rhessi
Inter-instrument calibration: XSM+RHESSI

XSM/RHESSI spectrum

XSM/RHESSI lightcurve 6-8kev

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

VÄÄNÄNEN/DENNIS

slide7

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

rhessi soho cds observations of chromospheric evaporation
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

slide9

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

correlation of fp motion with deposited energy

July 23, 2002

Correlation of FP Motion with Deposited Energy
  • 2-d model, sheet of area Ar
  • Ar = Lh∙Lv= 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

slide12

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

slide13

Coronal Sources in an occulted solar flare: 20-Jul-2002

100-200keV

50-100keV

20-30keV

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

BONE

slide14

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

slide15

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

slide16

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

slide17

WG 4+5

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 Steven’s presentation)

slide18

Rising Coronal X-ray Source and Erupting Filament

pos

i

t

i

on

Fe XIX Doppler velocity

SOHO/CDS slit

Flux rope

Vl<0

+

Vl>0

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

slide19

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

white light flares and energetics
White Light Flares and Energetics

1 px = 0.5” ~ 300km

Orange=25-50keV

Blue=WL

  • 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

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