survey of 4 years of sdo/eve observations of flare ... · belfast, 15 september 2015 the research...

Survey of 4 years of SDO/EVE observations of flare emission of H and

He lines Paulo Simões, Lyndsay Fletcher, Nicolas Labrosse, Graham Kerr!!SUPA, School of Physics and Astronomy, University of Glasgow [email protected]

Hinode 9 Belfast, 15 September 2015

The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007- 2013) under grant agreement no. 606862 (F-CHROMA),!

We do not know the typical characteristics of H Lyman and He II irradiance in flares Very few observations in the past e.g. Linsky et al. 1976 (He), Lemaire et al. 1984 (Lyβ), Porter et al. 1986 (He)

Observations vs. models see e-poster by David Kuridze (Hα obs. vs. models)

Benchmark for models Radiative hydrodynamics (RADYN, Flarix) or radiative transfers (RH, IAS) models

Why a survey of EVE flares?

103

104

105

106

107

Tem

pera

ture

, K

0 2 4 6 8 10Height, 108 cm

10−5

100

105

1010

1015

1020

Den

sity

, cm

−3

Hydrogenn=1n=2n=3n=4n=5

hii

103

104

105

106

107

Tem

pera

ture

, K

0 2 4 6 8 10Height, 108 cm

10−5

100

105

1010

1015

1020

Den

sity

, cm

−3

Heliumhe i 1s2 1se 0

he i 1s 2s 3se 1he i 1s 2s 1se 0he i 1s 2p 3po 4he i 1s 2p 1po 1he ii 1s 2se 1/2he ii 2s 2se 1/2

he ii 2p 2po 2he iii 0s 1se 0

Survey of EVE flares. [email protected]

How does the ionisation of H and He change during the flare? How does the ionisation depends on the heating (e.g. collisional heating by an electron beam)?

C III 97.7 nm (reference) Strong line, non-blended Well-associated with HXR

H I Lyman series: Ly β 102.6 nm Ly γ 97.26 nm Ly δ 94.98 nm

(in RADYN) He II 30.4 nm He I 58.4 nm O II-VI lines coming soon 97.5 97.6 97.7 97.8 97.9

nm

10−7

10−6

10−5

10−4

10−3

10−2

W/m

2

C III 97.7nm log T=4.8

90 92 94 96 98 100 102 104nm

10−7

10−6

10−5

10−4

10−3

10−2

W/m

2

H I 102.6nm log T=3.8H I 97.3nm log T=3.8H I 95.0nm log T=3.8

30.2 30.3 30.4 30.5 30.6nm

10−7

10−6

10−5

10−4

10−3

10−2

W/m

2

He II 30.4nm log T=4.7

58.2 58.3 58.4 58.5 58.6nm

10−7

10−6

10−5

10−4

10−3

10−2

W/m

2

He I 58.4nm log T=4.2Pre-flare Flare excess

EVE survey: Lines in EVE spectra


SDO/EVE: MEGS-A (5-37nm) and MEGS-B (35-105nm, intermittent observations) Most of the lines of interest are in MEGS-B. GOES flare list: Mar-2010 to May-2014 Number of flares:

8209 (above B) 5260 (above C)

With MEGS-B data: 263

Manually checking for useful data

257 flares ~5% of the GOES flares in the period

2010 2011 2012 2013 2014Year

10−7

10−6

10−5

10−4

10−3

GO

ES fl

ux, W

m−2

C

M

X

EVE eventsX: 5 (of 31)M: 64 (of 440)C: 188 (of 4789)B: 0 (of 2949)

EVE survey: Searching in the GOES flare list


01:00 01:20 01:40 02:00 02:20 02:40 03:00Start Time (15−Feb−11 00:57:13)

0.10

0.15

0.20

0.25

0.30

0.35

C II

I, m

W m

−2

01:00 01:20 01:40 02:00 02:20 02:40 03:00Start Time (15−Feb−11 00:57:13)

0.45

0.50

0.55

0.60

He

II, m

W m

−2

Pre-flare time C III peak time

peak flux

Pre-flare flux

He II flux at C III peak time

EVE survey: Methodology

01:45 02:00 02:15 02:30 02:45Start Time (15−Feb−11 01:38:15)

−0.05

0.00

0.05

0.10

0.15

0.20

mW

m−2

C III 97.7nm

01:45 02:00 02:15 02:30 02:45Start Time (15−Feb−11 01:38:15)

−0.05

0.00

0.05

0.10

0.15

mW

m−2

He II 30.4nm

01:45 02:00 02:15 02:30 02:45Start Time (15−Feb−11 01:38:15)

−0.005

0.000

0.005

0.010

0.015

mW

m−2

He I 58.4nm

01:45 02:00 02:15 02:30 02:45Start Time (15−Feb−11 01:38:15)

−0.005

0.000

0.005

0.010

0.015

0.020

mW

m−2

H I 102.6nm

01:45 02:00 02:15 02:30 02:45Start Time (15−Feb−11 01:38:15)

−0.004

−0.002

0.000

0.002

0.004

0.006

mW

m−2

H I 97.3nm

01:45 02:00 02:15 02:30 02:45Start Time (15−Feb−11 01:38:15)

−0.002

0.000

0.002

0.004

0.006

mW

m−2

H I 95.0nm

08:52 08:56 09:00 09:04Start Time (15−Apr−14 08:49:37)

−0.010.00

0.01

0.02

0.03

0.040.05

mW

m−2

C III 97.7nm

08:52 08:56 09:00 09:04Start Time (15−Apr−14 08:49:37)

−0.01

0.00

0.01

0.02

0.03

0.04

mW

m−2

He II 30.4nm

08:52 08:56 09:00 09:04Start Time (15−Apr−14 08:49:37)

−0.002

0.000

0.002

0.004

0.006

0.008

mW

m−2

He I 58.4nm

08:52 08:56 09:00 09:04Start Time (15−Apr−14 08:49:37)

−0.005

0.000

0.005

0.010

mW

m−2

H I 102.6nm

08:52 08:56 09:00 09:04Start Time (15−Apr−14 08:49:37)

−0.002

−0.001

0.000

0.001

0.002

0.003

mW

m−2

H I 97.3nm

08:52 08:56 09:00 09:04Start Time (15−Apr−14 08:49:37)

−0.002

−0.001

0.000

0.001

0.002

0.003

mW

m−2

H I 95.0nm

SO

L2

011-

02

-15

X2

.2

SO

L2

014

-0

4-

15 C

1.3

Manually find pre-flare times of each flare Find C III peak time Store line irradiance of pre-flare and peak Detection criterion: Irradiance at the peak time above 2-sigma of the pre-flare level


1 10 100 1000C III h97.70, mW m−2

1

10

100

1000

He

II h3

0.38

, mW

m−2

b=0.874±0.064a=1.349±1.231

y=axb

C: 177M: 64X: 5

1 10 100 1000He II h30.38, mW m−2

0.1

1.0

10.0

100.0

He

I h58

.43,

mW

m−2

b=0.931±0.205a=0.170±1.917

y=axb

C: 175M: 64X: 5

1 10 100 1000He II h30.38, mW m−2

1

10

100

1000

H I h1

02.5

7, m

W m

−2

b=1.061±0.123a=0.098±1.566

y=axb

C: 64M: 37X: 5

1 10 100 1000H I h102.57, mW m−2

0.1

1.0

10.0

100.0

H I h9

7.25

, mW

m−2

b=0.979±0.167a=0.324±1.367

y=axb

C: 24M: 31X: 5

0.1 1.0 10.0 100.0H I h102.57, mW m−2

0.1

1.0

10.0

100.0

H I h9

4.97

, mW

m−2

b=0.892±0.222a=0.304±1.549

y=axb

C: 14M: 27X: 5

EVE survey results: correlation of irradiances

Flare excess irradiances (approx. ranges) (at the C III peak time) C III – 5 - 280 mW/m2

He II – 3 - 210 mW/m2 He I - 0.7 - 27 mW/m2 H Lyβ - 2 - 30 mW/m2 H Lyγ- 0.9 - 11 mW/m2 H Lyδ- 0.7 - 10 mW/m2

Good correlations between the lines (with spread) Irradiances also correlate well with GOES flux


0.5 1.0 1.5 2.0 2.5 3.0 3.5ratio C III 97.7nm/He II 30.4nm

0

10

20

30

40

Num

ber o

f eve

nts

(tota

l 246

)

0.01

0.10

C II

I 97.

7nm

, erg

s−1

cm

−2

XMC

4 6 8 10 12 14 16 18ratio He II 30.4nm/He I 58.4nm

0

10

20

30

40

50

Num

ber o

f eve

nts

(tota

l 244

)

0.01

0.10

He

II 30

.4nm

, erg

s−1

cm

−2

XMC

4 6 8 10 12 14ratio He II 30.4nm/H I 102.6nm

0

5

10

15

20

25

Num

ber o

f eve

nts

(tota

l 106

)

0.1

He

II 30

.4nm

, erg

s−1

cm

−2

XMC

2 3 4 5 6ratio H I 102.6nm/H I 97.3nm

0

5

10

15

20

25

30

Num

ber o

f eve

nts

(tota

l 60)

0.01

H I

102.

6nm

, erg

s−1

cm

−2

XMC

2 4 6 8ratio H I 102.6nm/H I 95.0nm

0

5

10

15N

umbe

r of e

vent

s (to

tal 4

6)

0.01

H I

102.

6nm

, erg

s−1

cm

−2

XMC

EVE survey results: Line ratios

Line ratios: No correlation with GOES class No correlation with irradiance Range of common values


EVE survey results vs. models, He spectral index b=5

0 20 40 60time, s

0

2

4

6

8

He

II/H

e I ratio=3.2

spectral index b=6

0 20 40 60time, s

02

4

6

810

He

II/H

e I ratio=6.7

spectral index b=7

0 20 40 60time, s

0

5

10

15

20

He

II/H

e I ratio=12.5

spectral index b=8

0 20 40 60time, s

05

10

15

2025

He

II/H

e I ratio=22.7


0

10

20

30

40

50

Num

ber o

f eve

nts

(tota

l 244

)

0.01

0.10

He

II 30

.4nm

, erg

s−1

cm

−2

XMC

4 identical RADYN runs, changing the spectral index Spectral index relates to heating rate He II 30.4/He I 58.4 varies: 3 - 23


spectral index b=5

0 20 40 60time, s

2.0

2.5

3.0

3.5

4.0

Ly`/

Lya ratio=2.4

spectral index b=6

0 20 40 60time, s

2.0

2.5

3.0

3.5

4.0

Ly`/

Lya ratio=2.4

spectral index b=7

0 20 40 60time, s

2.0

2.5

3.0

3.5

4.0

Ly`/

Lya ratio=2.3

spectral index b=8

0 20 40 60time, s

2.0

2.5

3.0

3.5

4.0

Ly`/

Lya ratio=2.2

2 3 4 5 6ratio H I 102.6nm/H I 97.3nm

0

5

10

15

20

25

30

Num

ber o

f eve

nts

(tota

l 60)

0.01

H I

102.

6nm

, erg

s−1

cm

−2

XMC

4 identical RADYN runs, changing the spectral index Lyβ/Lyγ is not affected by it: 2.2 – 2.4


EVE survey results vs. models, H

2010 2011 2012 2013 2014Year

10−7

10−6

10−5

10−4

10−3

GO

ES fl

ux, W

m−2

C

M

X

EVE eventsX: 5 (of 31)M: 64 (of 440)C: 188 (of 4789)B: 0 (of 2949)

1 10 100 1000He II h30.38, mW m−2

0.1

1.0

10.0

100.0

He

I h58

.43,

mW

m−2

b=0.931±0.205a=0.170±1.917

y=axb

C: 175M: 64X: 5


0

10

20

30

40

50

Num

ber o

f eve

nts

(tota

l 244

)

0.01

0.10

He

II 30

.4nm

, erg

s−1

cm

−2

XMC

spectral index b=5

0 20 40 60time, s

0

2

4

6

8

He

II/H

e I ratio=3.2

spectral index b=6

0 20 40 60time, s

02

4

6

810

He

II/H

e I ratio=6.7

spectral index b=7

0 20 40 60time, s

0

5

10

15

20

He

II/H

e I ratio=12.5

spectral index b=8

0 20 40 60time, s

05

10

15

2025

He

II/H

e I ratio=22.7

SDO/EVE flare survey: summary

+ Survey of 4 years of EVE flares + 257 events (MEGS-B) + Characteristics of H

Lyman, He and C III emission lines

+ Benchmark for models (RADYN, Flarix, RH, etc.)

+ Line irradiances correlate well + also with GOES flux + found the range of irradiances

+ Ratio of line irradiances + Found range of ratios + no correlations with line irradiance or GOES

+ Ratios from models in good agreement with observations + He II 30.4 nm irradiance sensitive to beam’s spectral index (i.e. heating rate)

Survey of EVE flares. Contact: [email protected]

survey of 4 years of sdo/eve observations of flare ... · belfast, 15 september 2015 the research...

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