Studies on the 2002 July 23 Flare with RHESSI Ayumi ASAI Solar Seminar, 2003 June 2

RHESSI ( レッシ ) Reuven Ramaty High Energy Solar Spectrospic Imager Launched on 2002 Feburary 5 weight : 290kg length : 2.2m (solar panel : 5.7m) cost : ～ 70M$

RHESSI energy range : 3 keV – 17 MeV imaging maximum spatial resolution : beam size : 3.”3 FWHM spectroscopy high spectral resolution : 1~10 keV

2002 July 23 Flare 2002-July-23 00:15UT GOES X4.8 NOAA 0039 (near south-east limb) H  image taken with Sartorius Telescope GOES flux NoRH 34GHz NoRH 17GHz 00:0001:00 02:00

EUV(195 Å ) 像 EUV (195 Å ) images obtained with TRACE East West

Paper List 1.The Determination and Use of Mean Electron Flux Spectra in Solar Flares J.C. Brown 2.The Injected Power in Solar Flare Bremsstrahlung-Producing Electrons - Death to the 'Low Energy Cutoff A.G. Emslie 3.RHESSI Imaging Spectroscopy of the Large Gamma-Ray Flare of July 23, 2002 A.G. Emslie 4.H-alpha line polarization in the major flare of 2002 July 23 I. Observations and data analysis N. Firstova 5.Why there was no Solar Energetic Particle Event Associated with the RHESSI Flare of 2002 July 23? N. Gopalswamy 6.Electron Bremsstrahlung Hard X-ray Spectra, Electron Distributions and Energetics in the 2002 July 23 Solar Flare G.D. Holman 7.First gamma-ray images of a solar flare G.J. Hurford 8.Explanations for Deviations from Power- Law Behavior in the Hard X-ray Spectrum of the July 23, 2002 Solar Flare E.P. Kontar 1.Hard X-ray sources and motions in the July 23, 2002 gamma-ray flare S. Krucker 2.Bob Lin's opus 3.Implications of RHESSI Neutron-Capture Line Measurements on the Photospheric 3He/H ratio and Particle Scattering in the Coronal Magnetic Loop R.J. Murphy 4.Regularized Dynamic Electron Flux Spectra in the July 23, 2002 Solar Flare M. Piana 5.High-resolution observation of the solar positron-electron annihilation line G.H. Share 6.Directionality of flare-associated alpha- particles at the Sun G.H. Share 7.High-Resolution Spectroscopy of Gamma-Ray Lines from the X-Class Solar Flare of 23 July, 2002 D.M. Smith 8.RHESSI observation of the 1809 keV line from Galactic 26Al D.M. Smith 9.Radio and hard X-ray images of high-energy electrons in a compact X-class solar flare S.M. White 17 papers!

Paper List 1.The Determination and Use of Mean Electron Flux Spectra in Solar Flares J.C. Brown 2.The Injected Power in Solar Flare Bremsstrahlung-Producing Electrons - Death to the 'Low Energy Cutoff A.G. Emslie 3.RHESSI Imaging Spectroscopy of the Large Gamma-Ray Flare of July 23, 2002 A.G. Emslie 4.H-alpha line polarization in the major flare of 2002 July 23 I. Observations and data analysis N. Firstova 5.Why there was no Solar Energetic Particle Event Associated with the RHESSI Flare of 2002 July 23? N. Gopalswamy 6.Electron Bremsstrahlung Hard X-ray Spectra, Electron Distributions and Energetics in the 2002 July 23 Solar Flare G.D. Holman 7.First gamma-ray images of a solar flare G.J. Hurford 8.Explanations for Deviations from Power- Law Behavior in the Hard X-ray Spectrum of the July 23, 2002 Solar Flare E.P. Kontar 1.Hard X-ray sources and motions in the July 23, 2002 gamma-ray flare S. Krucker 2.Bob Lin's opus 3.Implications of RHESSI Neutron-Capture Line Measurements on the Photospheric 3He/H ratio and Particle Scattering in the Coronal Magnetic Loop R.J. Murphy 4.Regularized Dynamic Electron Flux Spectra in the July 23, 2002 Solar Flare M. Piana 5.High-resolution observation of the solar positron-electron annihilation line G.H. Share 6.Directionality of flare-associated alpha- particles at the Sun G.H. Share 7.High-Resolution Spectroscopy of Gamma-Ray Lines from the X-Class Solar Flare of 23 July, 2002 D.M. Smith 8.RHESSI observation of the 1809 keV line from Galactic 26Al D.M. Smith 9.Radio and hard X-ray images of high-energy electrons in a compact X-class solar flare S.M. White

Imaging 4 HXR sources –3 footpoint sources (> 30keV) –1 coronal sources (<30 keV) comparison between their positions with those of EUV(TRACE)/H  sources –footpoint sources  flare ribbons –coronal sources  above post-flare loops Krucker et al. (2003) ApJL

HXR Sources

Evolution of HXR Sources count velocity f1 f3

Radio Sources Radio data : Nobeyama NoRH White et al. (2003) ApJ

TRACE 12-20keV keV 17GHz 17 GHz sources are co-spatial with coronal HXR sources

 -Ray Imaging This flare is the first, and the only one so far,  -ray line event direct indication of the spatial properties of accelerated ions near the sun MeV line … –narrow deuterium line (neutron capture) –dense plasma (chromosphere) –red-shifted  precipitation Hurford et al. (2003) ApJ

 -Ray Lines ion acceleration collisions with the solar atmosphere  excited nuclei  emit prompt nuclear de-excitation lines secondary process  neutron capture line (2.223 MeV)  positron-annihilation line (511 keV)

Imaging of  -Ray Source sun

No Brightening in H  1  circle error : 6”

Discussions 2.2 MeV source was found to be displaced from the main bright point  there are significant differences in location and/or morphology between the electron- and ion-associated sources ion- and electron-light curves are similar to each other  common acceleration process

Spectroscopy integrated photon flux spectra : keV fitting isothermal + double power low (nonthermal) electron flux distribution thin-target / thick-target energy content Holman et al. (2003) ApJ

Fitting 10keV 100keV

Evolution of T / EM temperature emission measure GOES

Thick-Target electron indices

Energetics GOES RHESSI nonthermal

Discussions fitting of nonthermal electron : –double poewr law distribution with low energy cut-off : keV minimum total energy deposited by nonthermal electrons : 2.6×10 31 erg  comparable to thermal energy input  require imaging spectroscopy

Imagin Spectroscopy Evolution of spectra at 4 HXR sources Temperature, Emission measure Emslie et al. (2003) ApJ N S M C

fitting C : thermal N, S, M : nonthermal

coronal source (C) temperature  EM softer spectral index than footpoint sources (N,S,M) T EM

Summary Flare studies with RHESSI Imaging, Spectroscopy … other big flares … ? –2003 Mar 17/18 –2003 May 27/28/29 18 th paper on July 23, 2002 flare (by Asai et al.) ?

Double Power Low indices single power law break energy