Working Group 2 - Ion acceleration and interactions

2005 January 20 Flare High-energy emission delayed and has an extended tail. Particles reach Earth ~3 min after high-energy photons

Extended 511 keV flux comes from high-energy solar photons interacting in the spacecraft. Are these from solar pion radiation? High-energy appears to contain particles >07:15 and possibly neutrons >06:55.

Counts >20 MeV shows early peak coincident with sharp peak at 511 keV (likely to be high-energy solar photons causing instrumental line). Later peaks suggest neutron/particle detection and strong particle emission (lat > 30 o ). Abrupt drop in rate at Earth occultation consistent with high-energy solar photons.

movie

Spectrum after hard component subtracted

Calculated gamma-ray spectra vs flare-accelerated particle power- law index. Nuclear continuum masks narrow lines for hard spectra.

January 2005 flare Integral Gamma-rays Solar Energetic Particles

2005 January 20 Flare

n Debrunner et al, 1997

pions Vilmer et al, 2003

1-Minute GLE Count Rates

Solar Proton Spectra for Different GLE Phases

TRACE 1600A at 06:52:30 UT 2005 Jan – 500 keV 30, 50, 70, 90% contours keV centroid 1-  error circle

Imaged / Spectral MeV count ratios are consistent with 1. Ions interact in a compact region associated with footpoints. Not a from a broad region as expected from CME-related shocks. Ions are flare-accelerated Not all Jan keV flare counts are imaged--> consistent with solar 511 keV photons and instrumental photons from interactions of high-energy (>10 MeV) photons. May be possible to image >10 MeV photons in 2005 January 20 flare.

INTEGRAL Satellite on Oct 28 th 2003

RHESSI 2003 October 28 Time Histories Fit to 511 keV line flux indicates a hard spectrum, including contribution from pion decay 3  continuum just after impulsive peak also suggests positrons from pion decay RHESSI observed emission >20 MeV. SONG (CORONAS-F) observed >60 MeV gamma rays in peak consistent with neutron pion decay. Striking change in 511 keV line width after 11:16; nothing exceptional occurring in fluxes

Multi-loop structure during GLE proton injection Essential mean field structures selected by fiber bursts Main flaring arcade S N

Transient In EIT Between 11: UT 2003 Oct. 28

Power index = – 3.6 ± MeV = (3.1 ± 1.0)×10 27 [/MeV/sr] Neutron Spectrum on Oct 28 th 2003 (Tsumeb NM) Total energy flux of solar neutrons (>100MeV) : 3.1×10 25 [erg/sr]

Peaked at 19:45UT Solar neutrons were produced at 19:45UT ⇒ INTEGRAL Satellite on Nov 4 th 2003

Power index = – 3.9 ± 0.5 Flux at 100MeV = (1.5 ± 0.6)×10 28 [/MeV/sr] Total energy flux of solar neutrons (59 – 913MeV) : 3.4×10 26 [erg/sr] (χ 2 /dof = 0.92/3 = 0.31) Neutron Spectrum on Nov 4 th 2003 (Haleakala NM)

Time dependence of the 511 keV line Radioactive lines appearing after solar flares

30 minute delay 3 hr delay

Striking correlation of gamma-ray line and bremsstrahlung fluences in flares detected >300 keV RHESSI SMM After selection cuts Direct proportionality

Correlation coefficients between X-ray flux at 150 keV and gamma ray flux during the impulsive part of the flare Origin of the delay: acceleration or transport effects? Share et al, 2003 Delay of 12 s between hard X-ray flux at 150 keV and gamma ray lines The 23 July event Time delay analysisModelConclusionsIntroductionTime profile analysis Time delay between hard X-ray and gamma ray lines observed by RHESSI during the 23 July event

 -ray flux correctly reproduced for a constant spectral index but the injection amplitude are different Best fit: - n= cm -3 -  2 /L=10 -6 km -1 The 23 July eventTime delay analysisModelConclusionsIntroduction Time profile analysis Time delay between hard X-ray and gamma ray lines observed by RHESSI during the 23 July event Gamma-ray lines flux 2 nd step  =-3.75 (Lin et al, 2003) We change the ratio q 0 /q i for each injection, i.e. the number of electrons and ions accelerated in each injection is not necessarily the same