Thermal, Nonthermal, and Total Flare Energies Brian R. Dennis RHESSI Workshop Locarno, Switzerland 8...

Thermal, Nonthermal, and Thermal, Nonthermal, and Total Flare EnergiesTotal Flare Energies

Brian R. DennisBrian R. DennisRHESSI WorkshopRHESSI Workshop

Locarno, SwitzerlandLocarno, Switzerland8 – 11 June, 20058 – 11 June, 2005

Separating Thermal & NonthermalSeparating Thermal & Nonthermal

TemporalTemporal - gradual vs. impulsive - gradual vs. impulsive

SpatialSpatial - coronal vs. footpoint - coronal vs. footpoint

SpectralSpectral - exponential vs. power-law - exponential vs. power-law

SpectralSpectral – iron-line complexes – iron-line complexes- always thermal!!!?- always thermal!!!?

Difficulties with ContinuumDifficulties with Continuum

26 April 2003 Flare Time Profile26 April 2003 Flare Time Profile

A0 A1 A3 A1 A0

All Detectors

▬ 3 - 6 keV

▬ 6 – 12 keV

▬ 12 – 25 keV

▬ 25 – 50 keV

Time for spectrum

RHESSI Count-rate SpectrumRHESSI Count-rate Spectrum

Flux ratio vs. TemperatureFlux ratio vs. Temperature(Caspi & Lin, 2005)(Caspi & Lin, 2005)

Emissivity vs. TemperatureEmissivity vs. Temperature (Caspi & Lin, 2005) (Caspi & Lin, 2005)

Fe-line Equivalent WidthFe-line Equivalent Width26 April 200326 April 2003

CHIANTICoronal

Abundances

Ionization FractionIonization Fraction

Antonucci (1987 – SMM/BCS)

Mazzotta et al. (1998)

Less FeXXV than the calculations predict.

ConclusionsConclusions Fe & Fe/Ni complexes are real.Fe & Fe/Ni complexes are real. Fe centroid energies vary with T & count Fe centroid energies vary with T & count

rate.rate. Fe to Fe/Ni ratio varies with T.Fe to Fe/Ni ratio varies with T.

– Different dependency for different flares.Different dependency for different flares. Fe equivalent width varies with TFe equivalent width varies with T

– Data in A1 attenuator state most reliable.Data in A1 attenuator state most reliable.– Up to 50% less FeXXV than Mazzotta et al. Up to 50% less FeXXV than Mazzotta et al.

predict (Phillips).predict (Phillips). Eagerly await XSM spectra for comparison. Eagerly await XSM spectra for comparison.

Flare vs. CME EnergyFlare vs. CME Energy Flare thermal energies:Flare thermal energies:

– SXR-emitting plasma (GOES & RHESSI)SXR-emitting plasma (GOES & RHESSI)– Radiated energy (GOES)Radiated energy (GOES)– Conducted energy (GOES & RHESSI)Conducted energy (GOES & RHESSI)– Total Solar Irradiance increase (SORCE)Total Solar Irradiance increase (SORCE)

Flare nonthermal energiesFlare nonthermal energies– Electrons from HXRs (Holman)Electrons from HXRs (Holman)– Ions from gamma-rays (Share)Ions from gamma-rays (Share)

CME kinetic energyCME kinetic energy– (LASCO – Gopalswamy)(LASCO – Gopalswamy)

Thermal PlasmaThermal Plasma The thermal energy content of the thermal The thermal energy content of the thermal

plasma:plasma:

UUthth = 3 n = 3 nee V kT = V kT = 3 k T [EM f V3 k T [EM f Vapparentapparent]]1/21/2 erg erg

f is the filling factor (assumed to be 1) f is the filling factor (assumed to be 1)

Emission measures (EM) and temperatures (T) Emission measures (EM) and temperatures (T) obtained from both RHESSI and GOES soft X-ray obtained from both RHESSI and GOES soft X-ray observations.observations.

The source volumes (V) were obtained from The source volumes (V) were obtained from RHESSI 12 – 25 keV imagesRHESSI 12 – 25 keV images

V = f VV = f Vapparentapparent = f A = f A3/23/2

A is the area inside the contour at 50% of the peak value. A is the area inside the contour at 50% of the peak value.

Figure 1. RHESSI image at the impulsive peak of the 2 Nov. 2003 flare.Figure 1. RHESSI image at the impulsive peak of the 2 Nov. 2003 flare.Contours: blue: 12 – 25 keV (50%), magenta: 50 – 100 keV (30 & 70%)Contours: blue: 12 – 25 keV (50%), magenta: 50 – 100 keV (30 & 70%)

Radiated EnergyRadiated Energy

The energy radiated from the thermal plasma over The energy radiated from the thermal plasma over

all wavelengths:all wavelengths:

LLradrad = EM f = EM fradrad(T) ergs s(T) ergs s-1-1

ffradrad(T) (T) is the Chianti radiative loss function assuming is the Chianti radiative loss function assuming

coronal abundances.coronal abundances.

Total radiated energy from the flare plasma –Total radiated energy from the flare plasma –

LLtotaltotal = = nn[ L[ Lradrad(t) *(t) *DDt ] ergt ] erg

where the sum is over the duration of the SXR flare.where the sum is over the duration of the SXR flare.

Figure 2. Radiative losses vs. plasma temperature. Figure 2. Radiative losses vs. plasma temperature.

Mazzotta et al. (1998) ionization equilibrium

Rad

iati

ve E

ner

gy L

oss

– f ra

d (

erg

cm3 s

-1)

Temperature (K)

Conductive CoolingConductive Cooling

The conductive losses – LThe conductive losses – Lcondcond – were estimated assuming – were estimated assuming

classical conductionclassical conduction

LLcondcond = A = A kk00 T T5/25/2 VVT T 4 A/ 4 A/l l kk00 T T7/2 7/2 erg serg s-1-1

where where kk00 = 10= 10-6-6 erg cm erg cm-1-1 s s-1-1 K K-7/2-7/2

the classical Spitzer coefficientthe classical Spitzer coefficient

A is the loop cross-sectional area in cmA is the loop cross-sectional area in cm22

ll is the loop half length. is the loop half length.

A, A, l, l, and T can be determined from RHESSI images.and T can be determined from RHESSI images.

However, since there is so much uncertainty in estimating this However, since there is so much uncertainty in estimating this cooling component, no values are included in this analysis.cooling component, no values are included in this analysis.

X8.3 flare X8.3 flare 2 Nov. 20032 Nov. 2003

GOESGOESSXRSXRDataData

X8.3 flare X8.3 flare 2 Nov. 20032 Nov. 2003

GOESGOESSXRSXRDataData

CME vs. Flare Energies

0.1

1.0

10.0

100.0

1000.0

10000.0

0.01 0.1 1 10 100 1000

Flare Energy Component (1030 ergs)

CM

E K

inet

ic E

ner

gy

(10

30 e

rgs)

SXR-Emiting Plasma - Ltotal Peak Thermal Energy (Upeak) Electrons

Ions TSI Increase (SORCE) Equipartition

SORCE / TIM

28 October 2003 4 November 2003

23 July 200221 April 2002

3 Nov. 2003

CME vs. Flare Energies

0.1

1.0

10.0

100.0

1000.0

10000.0

0.01 0.1 1 10 100 1000

Flare Energy Component (1030 ergs)

CM

E K

inet

ic E

ner

gy

(10

30 e

rgs)

SXR-Emiting Plasma - Ltotal Peak Thermal Energy (Upeak) Electrons

Ions TSI Increase (SORCE) Equipartition

SORCE / TIM

28 October 2003 4 November 2003

23 July 200221 April 2002

3 Nov. 2003

Radiated vs. Thermal Flare Energies

0.001

0.010

0.100

1.000

10.000

100.000

0.1 1.0 10.0 100.0

Peak Thermal Energy, Upeak (1030 ergs)

Rad

iate

d E

ner

gy (

1030

erg

s)

Ltotal

LX,total

ConclusionsConclusions Flare and CME energies are correlated for the Oct/Nov 2003 Flare and CME energies are correlated for the Oct/Nov 2003

period.period. Total Flare and CME energies comparable to within a factor of 10.Total Flare and CME energies comparable to within a factor of 10. Peak energy in SXR-emitting plasma is only ~1% of total flare Peak energy in SXR-emitting plasma is only ~1% of total flare

energy in some cases.energy in some cases. Energy radiated by SXR-emitting plasma is only ~10% of total Energy radiated by SXR-emitting plasma is only ~10% of total

flare energy in some cases.flare energy in some cases. Energy in nonthermal electrons and ions can be a large fraction of Energy in nonthermal electrons and ions can be a large fraction of

the total flare energy.the total flare energy. Dominant flare energy in impulsive phase may be electrons and/or Dominant flare energy in impulsive phase may be electrons and/or

ions leading to early peak in total solar irradiance increase seen ions leading to early peak in total solar irradiance increase seen with SORCE/TIM.with SORCE/TIM.

Some of the measured radiant energy of flare may result from a Some of the measured radiant energy of flare may result from a decrease in the opacity of the lower chromosphere caused by a decrease in the opacity of the lower chromosphere caused by a decrease in the Hdecrease in the H– – concentration (Fontenla, private concentration (Fontenla, private communication).communication).