Transcript Constraints on Particle Acceleration from Interplanetary

Constraints on Particle
Acceleration from Interplanetary
Observations
R. P. Lin
together with L. Wang, S. Krucker at
UC Berkeley,
G Mason at U. Maryland,
and R. Mewaldt at Caltech
Krucker and Lin
2002
3
Electron - He-rich SEP events
- ~1000s/year at solar maximum
- dominated by:
- electrons of ~0.1 (!) to ~100 keV energy
- 3He ~10s keV/nuc to ~MeV/nuc
x10-x104 (!) enhancements
- heavy nuclei: Fe, Mg, Si, S enhancements
- high charge states
- associated with:
- small flares/coronal microflares
- Type III radio bursts
- Impulsive soft X-ray bursts (so also called
Impulsive SEP events)
L=v(t-to) or L/v=t-to
~0.05 MeV/nuc 1/v of 3He (Mason & Mazur)
~1.5 MeV/nuc 1/v for Electrons /
Electrons 0.14–13 keV
Electrons 20 – 350 keV
Ions ~ 0.5 – 1 MeV
Electron spectrum at 1AU
Typical electron spectrum can
be fitted with broken power law:
Break around: 30-100 keV
Steeper at higher energies
Oakley, Krucker, & Lin 2004
Comparing spectra
PHOTON SPECTRA:
Power law fit to HXR
spectra averaged over peak
ELECTRON SPECTRA:
Power law fit to peak flux
Assuming power spectra:
THIN:
THICK:
d=g–1
d=g+1
RESULTS:
1) correlation seen
2) values are between
Wang, Krucker, Lin,
& Gosling, 2005
Wang, Krucker, Lin, & Gosling 2005
Wang, Krucker, Lin, & Gosling 2005
Wang, Krucker, Lin, & Gosling 2005
The Sun is the most energetic particle
accelerator in the solar system:
- Ions up to ~ 10s of GeV
- Electrons up to ~100s of MeV
Acceleration to these energies occurs in
transient energy releases, in two (!) processes:
- Large Solar Flares, in the lower corona
- Fast Coronal Mass Ejections (CMEs), in
the inner heliosphere, ~2-40 solar radii
X-Class Flare of 2002 July 23
• 00:27:20–00:43:20 UT
• GOES X4.8
• Location: S13E72
(Lin et al. 2003)
RHESSI Gamma-Ray Flares
Ramaty High Energy
Solar Spectroscopic
Imager (RHESSI)
2002 July 23
X4.8
2003 June 17
M6.9
2003 October 28
X17
2003 October 29
X10
2003 November
2
2003 November
3
2004 November
10
2005 January 15
X8.3
2005 January 17
X3.8
2005 January 19
X1.3
X3.9
X2.5
X2.6
Mewaldt et al 2005
(Mewaldt et al. 2005)
e + - e-
n-capture
bremsstrahlung
narrow lines
broad lines
Oct. 28, 2003, RHESSI solar count spectrum from 11:06:20 – 11:10:04
(Smith et al. 2004, Share et al. 2004)
Murphy
2004
28 Oct 03
S16E08
γ-ray lines
(SEP)
Energy range
2 Nov 03
S15W56
γ-ray (SEP) γ-ray
Ne/C+O
(1.7)
2-20 MeV
2.0-3.2 (1.3) 1.6-3.2
e+/C+O
(2.8)
10-50 MeV
2.2-3.3 (2.0) 2.3-3.3
GOES soft X-rays
RHESSI 2.2 MeV line
RHESSI 100-200 keV
RHESSI hard X-rays
WIND/WAVES radio
WIND/3DP electrons
RHESSI Gamma-ray
- 20 Jan 05 Flare
20 JanSpectrum
05 Flare
In the Jan 20 Event the high energy particle-intensities reach Earth
just minutes after the x-rays from the flare
X-ray imaging
RHESSI X-ray imaging
during HXR peak:
Two ribbon flare with HXR footpoints
(contours) with thermal loop (image)
Timing
Red line (06:48UT):
Solar release time derived from
onsets at 1 AU assuming first
arriving particles travel with the
speed of light along L=1.2 AU
LASCO (06:54UT):
Around ~3 solar radii; lines
show height assuming a
constant velocity.
For v=2500km/s, CME could be
at ~1.5 solar radius at particle
release time.
Red crosses:
Rising SXR loops (top of SXI
emission)
2.2 MeV peaks at 06:47:30UT
HXRs peak at 06:45:00UT