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 Astrid VERONIG Alexander WARMUTH

Wednesday 11:00 – 13:00 RHESSI Thermal / low energy / multi  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 28 th event 16:30 – 18:00 Joint with WG5 – soft-hard-soft, number problem, etc. Friday 09:30 – 11:00 Energetics RHESSI WG4 – SCHEDULE

RHESSI Observations of the Iron-Line Feature  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  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 ? CHIFOR/PHILLIPS/DENNIS

RHESSI Quiet Sun Offpointing New limits in 3-17 keV –correlates with GOES in 3-7 keV  QS signal detected? –Fit Hot T, low EM (5-7MK, cm 3 ) or steep power-law (<-7) Comparable limits keV What will we get with more offpointing during Solar minimum? 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 HANNAH

PINT-of-ALE DEM DEM  exp(-T/T 0 ) 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 XSM GOES calibrations OK XSM/RHESSI low E needs factors explained Messenger/XSM underway XSM/RHESSI lightcurve 6-8kev XSM/RHESSI spectrum VÄÄNÄNEN/DENNIS

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 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

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

Reconnection rates and HXR characteristics VERONIG

Correlation of FP Motion with Deposited Energy July 23, 2002 L V  25 arcsec L V  100 arcsec L V  huge 2-d model, sheet of area Ar A r = L h ∙L v = area of reconn. region Correlation of Deposited Energy with Footpoint Separation  = acceleration efficiency Smooth correlation curve  ‘accurate’ (=stable) FP positions and fits of spectra Can derive the required current sheet vertical extent, L v FIVIAN

Red contour: keV Blue contour: 3-10 keV Green contour: 34GHz The distance and velocity between the two H  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 Footpoint motions and flare shear

20-30keV keV keV Coronal Sources in an occulted solar flare: 20-Jul-2002 Hard spectral index ~3.0 GOES+RHESSI gives density estimate of 2.2x10 11 cm -3. Column depth will collisionally stop electrons with 30-40keV How does > 100keV emission arise? BONE

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 Flux – Spectral Index correlations in coronal sources BATTAGLIA/BENZ

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

Moreton/coronal wave seen in radio Dotted line: Edge of H  Moreton wave Moreton wave in Radio Is the ‘termination shock’ suggested by Warmuth et al a standing shock at all? PICK

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)

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 Rising Coronal X-ray Source and Erupting Filament SOHO/CDS slit V l >0 V l <0 Flux rope time positionposition Fe XIX Doppler velocity Cooling loops + van Driel/Goff et al

SOHO/CDS slit TRACE EUV image   magnetic extrapolation  3-D flare loop orientation 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. RHESSI source ~60 km/s LASCO/C2 v~120 km/s Blabla blabla Blab l Height-time plot, high corona TRACE LASCO/C2 Contour: RHESSI keV EUV flux rope v~45-75 km/s Exponential growth Height-time plot, low corona v~60 km/s V l >0 V l <0 Flux rope time p o si ti o n Fe XIX Doppler velocity Cooling loops +

Flare energetics Total radiated energy in SXR (L SXR ) from GOES Total radiated energy from hot plasma (L hot ) from GOES T & EM. Total radiated energy from SORCE (L total ) CME KE from LASCO L total ~ KE CME ~ 10 L hot ~ 100 L SXR DENNIS

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