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
Survey of EVE flares. [email protected]
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
Survey of EVE flares. [email protected]
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
Survey of EVE flares. [email protected]
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
Survey of EVE flares. [email protected]
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
Survey of EVE flares. [email protected]
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
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 identical RADYN runs, changing the spectral index Spectral index relates to heating rate He II 30.4/He I 58.4 varies: 3 - 23
Survey of EVE flares. [email protected]
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
Survey of EVE flares. [email protected]
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
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
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]