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First RHESSI Results Brian R. Dennis RHESSI Mission Scientist Code 682. Space Sciences Directorate Monthly Report Monday, 25 March 2002. The Reuven Ramaty High Energy Solar Spectroscopic Image - RHESSI. Solar Flares.
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First RHESSI ResultsBrian R. DennisRHESSI Mission ScientistCode 682 Space Sciences Directorate Monthly Report Monday, 25 March 2002
The Reuven RamatyHigh EnergySolarSpectroscopic Image-RHESSI RHESSI Results
Solar Flares • Biggest explosions in the solar system - 1032 ergs or a billion megatons of TNT • Heat plasma to tens of millions of degrees. • Accelerate particles to near the speed of light - electrons to >100 MeV - ions to >10 GeV. • Magnetic energy released in the solar corona – mechanism unknown. RHESSI Results
Biggest Explosions(in tons of TNT equivalent) • Conventional TNT 3.8x103 • Atomic bomb (Hiroshima) 1.3x104 • Hydrogen bomb 2x107 • Tunguska event (1908) 1x107 • Mount Pinatubo (1991) 7x107 • Largest earthquake (Chile 1960) 3x109 • Asteroid that wiped out dinosaurs 1014 • Comet Shoemaker-Levy 9 on Jupiter 1014 • Largest solar flare 1016 RHESSI Results
Solar Flares How do you determine the energy release mechanism(s)? • Observe emissions from the heated plasma • Traditional H-alpha, UV, EUV (SOHO, TRACE), soft X-rays (Yohkoh) • Reveals magnetic field morphology • All energy release processes produce heat. • Observe the accelerated particles in space • ACE, WIND, SOHO, etc. • Many particles do not escape from the Sun • Transportation effects modify the information • Observe the emissions from the accelerated particles • Hard X-rays from electrons, gamma-rays from ions • Provides the most direct signature of the energy release mechanism(s) RHESSI Results
First RHESSI Flare Movie RHESSI Results
What’s Going On? RHESSI Results
RHESSI/SOHO/TRACE Overlay RHESSI Results
RHESSI Flare Spectra RHESSI Results
RHESSI Footpoint Flare RHESSI Results
RHESSI – SOHO (EIT) Overlay 20 Feb. 2002 11:06 UT Color: EIT Contours: RHESSI 30 – 80 keV 15 – 90% levels RHESSI Results
Shutters-Out Sensitivity GOES C-level RHESSI Results
Gamma-Ray Burst RHESSI Results
RHESSI Minimum Science Requirements 4.1.2.1 Perform hard X-ray (greater than 20 keV) imaging spectroscopy of solar flares with better than 4 arcsec spatial resolution and better than 3 keV energy resolution. 4.1.2.2 Perform high resolution (better than 3 keV FWHM at l MeV) spectroscopy of gamma-ray lines in solar flares. 4.1.2.3 Obtain observations of at least a hundred hard X-ray flares and ten gamma-ray (greater than 300 keV) flares. RHESSI Results
Solar Cycle Predictions RHESSI Results
Summary • RHESSI almost fully operational • All data and analysis software released • About 30 hard X-ray flares observed • Waiting on the Sun for Gamma-ray flares • Looking forward to many years of observations RHESSI Results