Solar flare observations with INTEGRAL/SPI Solar flare observations with INTEGRAL/SPI IEEC, Barcelona, September 23, 2004 (M. Gros, J. Kiener, V. Tatischeff et al.) TRACE & RHESSI, 28-Oct-2003 CHROMOSPHERE PHOTOSPHERE CORONA e-e- Hard X-rays p, ... Nuclear  -rays Neutrons 2.22 MeV  -ray line H 12 C p h 12 C*  Nuclear de-excitation lines: n

The INTEGRAL satellite IEEC, Barcelona, September 23, 2004  Launched (Proton) on 17 Oct 2002 Ge detector matrix Masks BGO shield ISGRI (CdTe) PICSIT (CsI) SPIIBIS E Range (MeV) ~0.02–10 ISGRI: ~0.02–1 PICsIT: ~0.16–10  (FWHM) 2.5°12’  E (FWHM) MeV keV 80 1 MeV  Scientific objectives: AGN,  -ray bursts, compact objects, novae, SNe, interstellar  -ray emissions...

Interest of SPI for solar flare physics IEEC, Barcelona, September 23, 2004  Compact array of 19 hexagonal Ge detectors (S tot =500 cm 2 ): good efficiency at high energy (compared to RHESSI) using "multiple events"  Anti-Coincidence veto System (ACS) of 91 BGO scintillator crystals: S pro ~6000–9000 cm 2

32 ° Ge detector matrix Masks BGO shield ISGRI PICSIT BGO shield SPI observations of the 2003 Oct 28 solar flare (X17.2) IEEC, Barcelona, September 23, 2004  During INTEGRAL observation of IC443 (rev 127; PI: A. Bykov)  Simulated response function for the satellite configuration during the flare: in progress (Weidenspointner et al.)  All results are preliminary

Measured spectra and time history  With all types of Ge events (including multiples 2-5) mostly instrumental pair prod. IEEC, Barcelona, September 23, 2004

4.44 and 6.13 MeV line characteristics Rest Energy (keV) % Redshift% FWHM   0.24  0.79    0.38  0.58   RHESSI results are for the 23 July, 2002 X4.8 flare (73° helio. angle) - Smith et al Compton IEEC, Barcelona, September 23, 2004

Best fit results:  12 C only :  /p = 0.00  = 20°  16 O only :  /p = 0.09  = 34°  12 C + 16 O :  /p = 0.03  = 29° common best fit 16 O best fit common best fit 12 C best fit 68.3 % C.L. 90 % C.L % C.L and 6.13 MeV line shape calculations IEEC, Barcelona, September 23, 2004  Detailed model based on laboratory data  Sensitive to the angular distribution of the accelerated particles and the  /p ratio

The 6.92 and 7.12 MeV lines of 16 O*  Fit with a fixed line shape: same relative redshift and FWHM as for the 6.13 MeV line  The two 16 O* lines at ~7 MeV are resolved for the first time  From a simplified model of solar  -ray absorption: Line Energy (MeV) Relative fluences    1.00    0.12 IEEC, Barcelona, September 23, 2004

Gamma-ray line ratios  Fast ion composition: Solar Energetic Particles (SEP) from impulsive flares  Fast ion energy spectrum: dN/dE  E -S  Nuclear de-excitation lines (thick target production model) compared to 2.22 MeV line production (Hua et al. 2002)   S S max for  /p=0.1 S min for  /p=0.1 ? IEEC, Barcelona, September 23, 2004

With a stochastic acceleration spectrum The source spectrum should be a modified Bessel function rather than a power law (e.g. Forman et al. 1986).  no improvement for C/O  : acceleration efficiency T: escape time from the acceleration region ? IEEC, Barcelona, September 23, 2004

With SMM and OSSE data  9 SMM flares with strong (and complete)  -ray line emission (SM95)  OSSE: 1991 June 4 flare (Murphy et al. 1997)  RHESSI results not yet taken into account ?  S determination for the 1989 Nov 15 flare Correction for heliocentric angle IEEC, Barcelona, September 23, 2004

The 12 C/ 16 O line ratio problem IEEC, Barcelona, September 23, 2004  Calculated  4.44)/  6.13) overestimates by a factor of ~1.5 the average line ratio obtained from SMM, OSSE and SPI data.  Origin of the problem: - the interaction model ? - the cross sections ? - the abundances of 12 C and 16 O in the ambient medium (coronal, from gradual event SEP) ?  comparison with the 2 other significant lines detected with SMM and OSSE: at 1.37 ( 24 Mg*) and 1.63 MeV ( 20 Ne*) from Ramaty et al.

Cross sections (1) Mainly from KMR02 (ApJ Suppl), the figures.  4.44 MeV line S=3 S=4.5 a: 12 C(p,p’) 12 C*47.4% 43.1% b: 14 N(p,x) 12 C* (  )1.6% 0.2% c: 16 O(p,x) 12 C*35.7% 9.5% d: 12 C( ,  ’) 12 C*8.7% 39.3% e: 14 N( ,x) 12 C* (  )0.4% 0.3% f: 16 O( ,x) 12 C*6.3% 7.5% A(b,c)D: cross section measured by the  -ray method (10–20% uncertainties) (  ): Cross sections overestimated in KMR02 ; calculated with EMPIRE-II (nuclear statistical model) (with  /p=0.1) IEEC, Barcelona, September 23, 2004

Cross sections (2)  6.13 MeV line  MeV ( 16 O*) MeV ( 15 O*), but not the MeV line ( 15 N*), see Mandzhavidze et al. (1999). S=3 S=4.5 a: 16 O(p,p’) 16 O*67.0% 42.7% b: 20 Ne(p,x) 16 O*6.0% 1.6% c: 16 O(p,x) 15 O*11.0% 0.5% d: 16 O( ,  ’) 16 O*15.2% 54.4% e: 20 Ne( ,x) 16 O* (  )0.6% 0.8% f: 16 O( ,x) 15 O*<0.1% <0.1% (  ): Cross section not considered in KMR02, calculated with EMPIRE-II IEEC, Barcelona, September 23, 2004

Cross sections (3)  7 MeV lines  6.92 MeV MeV ( 16 O*) S=3 S=4.5 a: 16 O(p,p’) 16 O* % 40.0% c: 16 O( ,  ’) 16 O* % 60.0% b: 16 O(p,p’) 16 O* % 52.3% d: 16 O( ,  ’) 16 O* % 47.7% Minor contributions (neglected) from 20 Ne spallation (EMPIRE-II) IEEC, Barcelona, September 23, 2004

Cross sections (4)  1.63 MeV line  MeV ( 20 Ne*) MeV ( 23 Na*) MeV ( 14 N*) S=3 S=4.5 a: 20 Ne(p,p’) 20 Ne* 55.1% 62.1% b: 24 Mg(p,x) 20 Ne*, 23 Na* 20.5% 4.1% c: 28 Si(p,x) 20 Ne* 5.3% 0.5% d: 20 Ne( ,  ’) 20 Ne* 7.0% 27.1% e: 24 Mg( ,x) 20 Ne*, 23 Na* 2.5% 1.3% a’: 14 N(p,p’) 14 N* 4.1% 2.9% b’: 16 O(p,x) 14 N* 4.9% 0.3% c’: 14 N( ,  ’) 14 N* 0.6% 1.8% IEEC, Barcelona, September 23, 2004

Cross sections (5)  1.37 MeV line  MeV ( 24 Mg*) MeV ( 55 Fe*) MeV ( 59 Ni*) S=3 S=4.5 a: 24,25,26 Mg(p,x) 24 Mg* 85.8% 74.5% b: 28 Si(p,x) 24 Mg* 7.2% 0.9% c: 56 Fe(p,x) 55 Fe* 1.1% 0.1% d: 24 Mg( ,  ’) 24 Mg* 5.3% 22.2% e: 56 Fe( ,n) 59 Ni* 0.6% 2.3% IEEC, Barcelona, September 23, 2004

  theory =20% (due to  ) added in quadrature to  data for the  2 probabilities  Goodness-of-fits:  Ambient medium  coronal  but A SEP (C) is too high   /p=0.1 is favored. Then Ne/O  0.15 and Mg/O  0.20 The Dec 16, 1988 Flare. Not included in the probability calculations. Ambient  photosph. ? IEEC, Barcelona, September 23, 2004 With the 1.63 and 1.37 MeV lines

The Dec 16, 1988 Flare. Not included in the probability calculations. Ambient  photosph. ?  same results, but on average the probabilities are slightly lower as  S  With  S from  2.22 /  6.13 only IEEC, Barcelona, September 23, 2004

 Good consistency of the 3 probability distributions  From maximum likelywood: (C/O) =0.28  0.03 (1  ) 0.28  0.08 (2  ) The C abondance in the interaction region IEEC, Barcelona, September 23, 2004 With  /p=0.1 (C/O) SEP =0.46  0.01 (Reames 1999) (C/O) pho =0.50  0.08 (Lodders 2003)

A new photospheric C abundance ? Anders & Grevesse (1989) Grevesse & Sauval (1998) Holvecker (2001) Lodders (2003) Asplund et al. (2004), A&A for O, in prep. for C IEEC, Barcelona, September 23, 2004 (C/O) chr ~0.3 but (C/O) pho =0.5 ? A pho (C) and A pho (O) are uncertain: recent substantial revisions (NLTE, 3D models) A reduced A sol (C) would better fit the C abondance gradient in the Galactic disk (see Hou et al. 2000, fig. 6) for  /p=0.1 speculative

The photospheric 3 He abundance*  The time evolution of the 2.22 MeV line emission is sensitive to A pho ( 3 He):  { 3 He(n,p) 3 H}  1.6·10 4  { 1 H(n,  ) 2 H}  NRC = 1 / {n( 3 He)·  NRC ·v n } =  RC  (H/ 3 He)  6.25·10 -5 IEEC, Barcelona, September 23, 2004  Neutron-production time history  prompt  -ray line emission (good quality data with SPI) *Not measured by atomic spectroscopy *Not measured by atomic spectroscopy Neutrons 2.22 MeV H n pe-e- e n 3 He 3 H n p

ChromospherePhotosphere No PAS Strong PAS The magnetic loop model IEEC, Barcelona, September 23, 2004 (Hua, Lingenfelter, Murphy, Ramaty...) CHROMOSPHERE PHOTOSPHERE CORONA isotropic accelerated- particle release  MHD turbulence  pitch-angle scattering B  (pressure)  constant B magnetic mirroring (sin 2  B) “loss cone"  No PAS (mean free path   ): “fan beam“ of interacting particles (i.e. parallel to the solar surface)  Strong PAS: loss cone continuously repopulated  “downward beam“ Hua et al. (2002)

Calculated 2.22 MeV lightcurves IEEC, Barcelona, September 23, 2004  Monte-Carlo code (Hua et al. 1987, 2002) to simulate: (i) the propagation and interaction of the accelerated particles (ii) the neutron production and propagation (iii) the 2.22 MeV line production and absorption  For instantaneous release of the accelerated particles, the 2.22 MeV lightcurves fall faster with increasing PAS (decreasing ) and increasing 3 He/H (see Murphy et al. 2003)

 The two free parameters are strongly correlated  from 4.44 and 6.13 MeV line shapes  more accurate 3 He/H  Solar neutron measurements (monitors + CORONAS/SONG) could help... The photospheric 3 He abundance: results  fan beam downward beam  IEEC, Barcelona, September 23, 2004

 From  -ray spectroscopy of the 2003 Oct 28 solar flare with SPI: - energy spectrum of the accelerated ions (  -ray line fluences) - accelerated  /p ratio (  -ray line shapes and fluences) - amount of PAS in magnetic loop/angular distribution of the interacting particles (  -ray line shapes and 2.22 MeV lightcurve)  acceleration and transport processes - ambient C abundance (  -ray line fluences) - ambient 3 He abundance (2.22 MeV lightcurve)  solar composition and atmospheric response  Much more to do: - timing analyses using the ACS (and radio data) - analyses of the 2003 Nov 4 flare (near the solar limb !)... Summary IEEC, Barcelona, September 23, 2004