solar flare observations with integral/spi

Solar flare observations Solar flare observations with INTEGRAL/SPIwith INTEGRAL/SPI

IEEC, Barcelona, September 23, 2004

(M. Gros, J. Kiener, V. Tatischeff et al.)

TRACE & RHESSI, 28-Oct-2003

CHROMOSPHERE

PHOTOSPHERE

CORONA

e-

Hard X-raysp, ...

Nuclear -rays

Neutrons

2.22 MeV -ray line

H

12Cp

h

12C*

Nuclear de-excitation lines:

n

The INTEGRAL satelliteThe INTEGRAL satellite


Launched (Proton) on 17 Oct 2002

Ge detector matrix

Masks

BGO shield

ISGRI (CdTe)

PICSIT (CsI)

SPI IBIS

E Range (MeV)

~0.02–10

ISGRI: ~0.02–1 PICsIT: ~0.16–

10

(FWHM)

2.5° 12’

E (FWHM)

3 keV @ 1.7 MeV

9 keV @ 100 keV 80 keV @ 1

MeV

Scientific objectives: AGN, -ray bursts, compact objects, novae, SNe, interstellar -ray emissions...

Interest of SPI for solar flare Interest of SPI for solar flare physicsphysics


Compact array of 19 hexagonal Ge detectors (Stot=500 cm2): good efficiency

at high energy (compared to RHESSI) using "multiple events"

Anti-Coincidence veto System (ACS) of 91 BGO scintillator crystals: Spro~6000–9000 cm2

32 °

Ge detector matrix

Masks

BGO shield

ISGRI

PICSIT

BGO shield

SPI observations of the 2003 Oct 28 solar flare SPI observations of the 2003 Oct 28 solar flare (X17.2)(X17.2)


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 Measured spectra and time historyhistory

With all types of Ge events (including multiples 2-5)

mostly instrumental

pair prod.


4.44 and 6.13 MeV line characteristics4.44 and 6.13 MeV line characteristics

Rest Energy(keV)

% Redshift % FWHM

4438.030.632 0.097

1.67 0.24

0.79 2.06

6128.630.59 0.12 1.95 0.38

0.58 1.99

+ 0.95- 0.65

+ 0.24- 0.29

RHESSI results are for the 23 July, 2002 X4.8 flare (73° helio. angle) - Smith et al. 2003

+ 1.11- 0.83

+ 0.23- 0.22

Compton


Best fit results:12C only : /p = 0.00 = 20°16O only : /p = 0.09 = 34°12C +16O : /p = 0.03 = 29°

common best fit16O best fit

common best fit12C best fit

68.3 % C.L.90 % C.L.95.4 % C.L.

4.44 and 6.13 MeV line shape 4.44 and 6.13 MeV line shape calculationscalculations


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 The 6.92 and 7.12 MeV lines of 1616O*O*

Fit with a fixed line shape: same relative redshift and FWHM as for the 6.13 MeV line

The two 16O* lines at ~7 MeV are resolved for the first time

From a simplified model of solar -ray absorption:

Line Energy (MeV)

Relative fluences

2.2 10.7 1.7

4.4 0.92 0.14

6.1 1.00 0.17

6.9 0.33 0.13

7.1 0.20 0.12


Gamma-ray line ratiosGamma-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

Smax for /p=0.1

Smin for /p=0.1

?


With a stochastic acceleration With a stochastic acceleration spectrumspectrum

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

?


With SMM and OSSE dataWith 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


The The 1212C/C/1616O line ratio O line ratio problemproblem


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 12C and 16O in the ambient medium (coronal, from gradual event SEP) ?

comparison with the 2 other significant lines detected with SMM and OSSE: at 1.37 (24Mg*) and 1.63 MeV (20Ne*)

from Ramaty et al.

Cross sections Cross sections (1)(1)

Mainly from KMR02 (ApJ Suppl), the figures.

4.44 MeV line S=3 S=4.5

a: 12C(p,p’)12C* 47.4%

43.1%

b: 14N(p,x)12C* () 1.6% 0.2%

c: 16O(p,x)12C* 35.7% 9.5%

d: 12C(,’)12C* 8.7% 39.3%

e: 14N(,x)12C* () 0.4% 0.3%

f: 16O(,x)12C* 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)



6.13 MeV line 6.129 MeV (16O*) + 6.175 MeV (15O*),

but not the 6.322 MeV line (15N*), see Mandzhavidze et al. (1999).

S=3 S=4.5

a: 16O(p,p’)16O* 67.0% 42.7%

b: 20Ne(p,x)16O* 6.0% 1.6%

c: 16O(p,x)15O* 11.0% 0.5%

d: 16O(,’)16O* 15.2% 54.4%

e: 20Ne(,x)16O* () 0.6% 0.8%

f: 16O(,x)15O* <0.1% <0.1%

(): Cross section not considered in KMR02, calculated with EMPIRE-II



7 MeV lines 6.92 MeV + 7.12 MeV (16O*)

S=3 S=4.5

a: 16O(p,p’)16O*6.92 78.0% 40.0%

c: 16O(,’)16O*6.92 22.0% 60.0%

b: 16O(p,p’)16O*7.12 87.1% 52.3%

d: 16O(,’)16O*7.12 12.9% 47.7%

• Minor contributions (neglected) from 20Ne spallation (EMPIRE-II)



1.63 MeV line 1.634 MeV (20Ne*) + 1.636 MeV (23Na*) + 1.635 MeV (14N*)

S=3 S=4.5

a: 20Ne(p,p’)20Ne* 55.1%

62.1%

b: 24Mg(p,x)20Ne*,23Na* 20.5% 4.1%

c: 28Si(p,x)20Ne* 5.3% 0.5%

d: 20Ne(,’)20Ne* 7.0% 27.1%

e: 24Mg(,x)20Ne*,23Na* 2.5% 1.3%

a’: 14N(p,p’)14N* 4.1% 2.9%

b’: 16O(p,x)14N* 4.9% 0.3%

c’: 14N(,’)14N* 0.6% 1.8%



1.37 MeV line 1.369 MeV (24Mg*) + 1.370 MeV (55Fe*) + 1.367 MeV (59Ni*)

S=3 S=4.5

a: 24,25,26Mg(p,x)24Mg* 85.8%

74.5%

b: 28Si(p,x)24Mg* 7.2% 0.9%

c: 56Fe(p,x)55Fe* 1.1% 0.1%

d: 24Mg(,’)24Mg* 5.3% 22.2%

e: 56Fe(,n)59Ni* 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 ASEP(C) is too high

/p=0.1 is favored. Then Ne/O0.15 and Mg/O0.20The Dec 16, 1988

Flare. Not included in the probability calculations. Ambient photosph. ?


With the 1.63 With the 1.63 and 1.37 MeV and 1.37 MeV

lineslines

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 With S from S from 2.222.22//6.136.13 only only


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 The C abondance in the interaction regionregion


With /p=0.

1(C/O)SEP=0.460.01

(Reames 1999)

(C/O)pho=0.500.08

(Lodders 2003)

A new photospheric C abundance 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


(C/O)chr~0.3 but (C/O)pho=0.5 ?

Apho(C) and Apho(O) are uncertain:

recent substantial revisions (NLTE, 3D models)

A reduced Asol(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 The photospheric 33He He abundance*abundance*

The time evolution of the 2.22 MeV line emission is sensitive to Apho(3He):

{3He(n,p)3H}1.6·104{1H(n,)2H}

NRC = 1 / {n(3He)·NRC·vn}

= RC (H/3He) 6.25·10-5


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

p e-

e n 3He

3H

n

p

Chromosphere Photosphere

No PAS

Strong PAS

The magnetic loop model The magnetic loop model


(Hua, Lingenfelter, Murphy, Ramaty...)

CHROMOSPHERE

PHOTOSPHERE

CORONA

isotropic accelerated- particle release

MHD turbulence pitch-angle scattering

B (pressure)

constant B

magnetic mirroring (sin2 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 lightcurvesCalculated 2.22 MeV lightcurves


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 3He/H (see Murphy et al. 2003)

The two free parameters are strongly correlated from 4.44 and 6.13 MeV line shapes more accurate 3He/H Solar neutron measurements (monitors + CORONAS/SONG) could help...

The photospheric The photospheric 33He abundance: He abundance: resultsresults

fan beam

downward beam


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 3He 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 !)

...

SummarSummaryy


solar flare observations with integral/spi

Documents

mev line characteristics

mev lines

mev gray lineh12cphn12c

mev line production

gray bursts

fixed line shape

average line ratio

solar flare observations