RHESSI Paris workshop

Plenary session, July 28 2003

WG1, Holman:
 * Mean electron flux and injected flux distribution (Brown)
 * inversion/forward-fit comparison
 * Johns-Lin technique - no smoothing per se, but implicitly in binning
 * all techniques show the 50-60 keV dip in 23-Jul and other flares
 * blind test against 4 cases of input spectra, with encouraging results
  for an assumed 5% systematic error plus Poisson statistics for a very
  large flare
 * soft-hard-soft (Grigis)
 * break statistics comparing RHESSI and BATSE (Gan) => BATSE spectra are
  not calibrated correctly below 100 keV
 * variation of low-energy cutoff (Galloway)
 * low-energy turnovers (St.-Hilaire)
 * albedo (Kontar): soon to be implemented
 * albedo observations (Schmahl): two-omega distributions in roll
 * Kontar method albedo corrections (Kasparova):
 * energetics
 * (something missed)

WG2, Share:
 * direct redshift and neutron-capture line history give discrepant views
  of the PAD
 * may require tilted loops
 * new suggestion of small alpha/proton ratio, but RHESSI sees alpha-alpha
 * hard spectra => pions, neutrons (GONG) and possibly GLE (neutron monitor) 
  neutrons 
 * are solar observations consistent with SEP occurrence? No; E flare leads
  to W disturbance that is well connected
 * broadening of 511 keV line, formed at 10^14 cm^-3 at TR temperatures.
  Late narrow component -> 10^15 density at >25% ionization; no other 
  signature for narrowing identified
 * Oct. 28 and Nov. 2 consistent with pion production. Could the new mm-wave
  component be identified with the resulting positrons? HE bremsstrahlung
  spectrum is gamma ~ 2, and Gerard is happy.
 * abundances. Feelings are hurt because astronomers don't seem to care that
  the gamma-ray spectrum provides C and 3-He abundances
 * 3-He solar and in-situ observations
 * need better cross-sections!
 * chromosphere seems to have FIP bias, even at 10^14 density? 
  
WG3, White:
 * the most effective of the radio groups to date
 * radio phenomenology is rich and under-appreciated
 * decimeter/HX correlations (Moussas), especially for Oct. 28
 * spikes in DM (Farnik): detailed structure does not seem to correlate, 
  though on longer time scales there is something (eg 5-aug-03). HX leads
  radio by 2-15 s
 * RHESSI lightcurve demodulation (Arzner and Hurford); Arzner finds some
  excellent III/HX correlations
 * best correlation @ HF III's (Benz) 
 * spikes imaged do not match HX (Khan)
 * NRH comparisons of III locations with Schrijver-Derosa fields show
  3/3 agreement, including large non-radial connections
 * Oct 28 particle event, not well connected but related to secondary
  brightenings at some distance 
 * coronal sources (Kane and Kundu)
 * mismatch between radio and X-ray spectra (Trottet): flattening in MeV
  range may straighten things out
 * submm flux too large for ff; rising spectrum at shortest wavelengths.
  Could be pion decay positrons?

WG4, Fletcher:
 * energetics (Berlicki, Li, Hudson)
 * Fe feature (Caspi, Dennis)   
 * Oct. 28 event (Gallagher, Demoulin-Mandrini-Van Driel, Benz, Hudson) 
 * microflares (Christe, Hanna, Kundu, Benz)
 * footpoints (Mrozek, Somov) 
 * coronal sources (Veronig-Temmer, Somov, Hudson)

Theory, Vlahos:
 * Vlahos, Zharkova, Demoulin, Holman - splinter group
 * current sheets and acceleration - promising
 * number problem - baffling
 * stressed topologies of complex fields - promising
 * stochastic current sheets - Turkmani et al. preprint 
 * open questions - numerous