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
5 points sm 41-300 MeV
5 points sm 6.2-10.8 MeV
Count s
-1
Count s
-1
100
10
06:44
06:45
06:46
06:47
06:48
UT, hh:mm
06:49
06:50
06:51
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 > 30o).
Abrupt drop in rate at Earth occultation consistent with high-energy solar
photons.
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Spectrum after hard component subtracted
Calculated gamma-ray spectra vs flare-accelerated particle powerlaw index. Nuclear continuum masks narrow lines for hard spectra.
January 2005 flare Integral
Gamma-rays
Solar Energetic Particles
2005 January 20 Flare
2005 January 20 Flare
2005 January 20 Flare
n
Debrunner et al, 1997
Vilmer et al, 2003
pions
1-Minute GLE Count Rates
Solar Proton Spectra for
Different GLE Phases
TRACE 1600A at 06:52:30 UT 2005 Jan. 20
250 – 500 keV 30, 50, 70, 90% contours
2215-2231 keV centroid 1- error circle
Imaged / Spectral 2.223 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. 20 511 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 28th 2003
RHESSI 2003 October 28 Time Histories
Fit to 511 keV line flux indicates a
hard spectrum, including
contribution from pion decay
3g 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
N
Essential mean field
structures selected by
fiber bursts
S
Main flaring arcade
Transient
In EIT
Between
11:12 11-24 UT
2003
Oct. 28
Neutron Spectrum
on Oct 28th 2003
(Tsumeb NM)
• Power index
= – 3.6 ± 0.3
• Flux @ 100MeV
= (3.1 ± 1.0)×1027
[/MeV/sr]
Total energy flux of
solar neutrons
(>100MeV) :
3.1×1025 [erg/sr]
INTEGRAL Satellite
on Nov 4th 2003
Peaked at 19:45UT
⇒
Solar neutrons
were produced at
19:45UT
Neutron Spectrum
on Nov 4th 2003
(Haleakala NM)
• Power index
= – 3.9 ± 0.5
• Flux at 100MeV
= (1.5 ± 0.6)×1028
[/MeV/sr]
(χ2/dof = 0.92/3 = 0.31)
Total energy flux of
solar neutrons
(59 – 913MeV) :
3.4×1026 [erg/sr]
Radioactive lines appearing after solar flares
Time dependence of
the 511 keV line
30 minute delay
3 hr delay
Striking correlation of gamma-ray line and
bremsstrahlung fluences in flares detected >300 keV
After selection cuts
Direct proportionality
RHESSI
SMM
Introduction
The 23 July event
Model
Time delay analysis
Time profile analysis
Conclusions
Delay of 12 s between hard X-ray flux
at 150 keV and gamma ray lines
Share et al,
2003
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?
Time delay between hard X-ray and gamma ray lines observed by RHESSI during the 23 July event
Introduction
The 23 July event
Model
Time delay analysis
Time profile analysis Conclusions
Gamma-ray lines flux 2nd step
=-3.75 (Lin et al, 2003)
We change the ratio q0/qi for each injection, i.e. the number of
electrons and ions accelerated in each injection is not necessarily the
same
g-ray flux correctly
reproduced for a constant
spectral index but the
injection amplitude are
different
Best fit:
- n=1.1010 cm-3
- 2/L=10-6 km-1
Time delay between hard X-ray and gamma ray lines observed by RHESSI during the 23 July event