ARTEMIS IV, Thermopylae

ARTEMIS IV
observing the Sun at t 20 to 650 MHz at Thermopylae
X. Moussas(1), P. Tsitsipis(1,3), A. Kontogeorgos(1,3), C. Caroubalos(1), P. Preka-Papadema(1),
A. Hillaris(1), C. Alissandrakis (4), J.-L. Bougeret(2), G. Dumas(2),
(1) University of Athens, GR-15783 Panepistimiopolis Zographos, Athens, Greece
(2) LESIA, Observatoire de Paris, UMR CNRS 8109, F-92195 Meudon Cedex, France
(3) Department of Electronics, Technological Education Institute of Lamia, Lamia, Greece
(4) Section of Astro-Geophysics, Department of Physics, University of Ioannina, GR-45110 Ioannina, Greece
ARTEMIS-IV is a solar radio spectrograph (a franco-hellenic collaboration) which
observes the Sun continuously in the frequency rate of 20 to 650 MHz (recording 10
spectra per second) and in the 270 to 450 MHz (recording 100 spectra per second), or
~1.2 to 1,6 Gb/day. The instrument is situated at Thermopylae (Central Greece).
With this instrument we have observed a large number of solar radio bursts, several of
them associated with CMEs. We have analysed the fine structure of several events with
pulsating structure and fiber bursts.
2-7 May 2005, Graz, Austria

The fine structure in three solar type IV radio bursts was studied using the French-
Greek ARTEMIS-IV multichannel radio spectrograph. The bursts were recorded
during three major solar events, on the 26 and 28 October.and 3 Nov. 2003 and
January 2005; these we associated with intense flares and CMEs. The observed fine
structure includes inter-mediate drift bursts (fibers) and pulsations.
The complexity and overlapping of the various spectral characteristics necessitated
the utilization of certain, 2D-FFT based, filtering processes, aiming firstly at
structure detection in the frequency-time plane (ie the dynamic spectrum) and
secondly in the separation of fibers and pulsations and the suppression of the type
IV continuum.
This methodology results also to the fibers frequency drift rate distributions and
their evolution in time. These fiber frequency drift distributions may be interpreted
as the exciter velocity distributions, using a Newkirk coronal density model; the
latter may be used as diagnostics of the magnetic field restructuring and energy
release during a solar energetic event (flare and/or CME).
Artemis IV will provide complementary data to the STEREO/WAVES experiment.

The oldest known map of the Sky Debra, Germany, 1500 B.C.
Ο αρχαιότερος χάρτης του ουρανού Debra, Γερµανία, 1500 π.Χ
The oldest known observatory,
near Goseck, Germany, 5000 B.C.
Το αρχαιότερο αστεροσκοπείο,
στο Goseck, Γερµανία, 5000 π.Χ.

Prehistoric observatory
Stonehenge, U.K. 2000 200 B.C.

First record of an eclipse in China, 2136 BC
Πρώτη καταγραφή έκλειψης στην Κίνα το 2136 π.Χ.

University of Athens
Cardiff University
University of Thessaloniki
National Archeological Museum
Athens
Under the Aegis of the
Greek Ministry of Culture
and support by the Leverhulme
Foundation
The Antikythera Mechanism
The Greek astronomical computer of the 1 st century B.C.

A Holistic View to Study Explosive Solar Phenomena
and Space Weather
1. optical
2. UV
3. X-rays
4. gamma rays
5. radio bursts (type III, type II and type IV) ARTEMIS
6. energetic particles, electron and spectra, anisotropies etc
7. cosmic rays
8. solar wind plasma (velocity, density, temperature, magnetic
field)
9. LOFAR & LOIS
• many observing points (spacecrafts, on the Moon etc)

Why we need to know
and forecast space weather?
• Detailed and comprehensive data on
solar-terrestrial relationships, which
drastically affect the Earth’s
ecosystem, are needed.
• reliable space weather forecast can–
in analogy with a reliable terrestrial
weather forecast–mitigate
undesirable consequences of space
weather, including economical ones

ARTEMIS IV is the
Franco-Hellenic
solar radiospectrograph
operated by the University
of Athens at Thermopylae
frequency range of 20 to 650 MHz
two receivers operating in parallel.
the Global Spectral Analyser (ASG),
a sweep frequency receiver and
the Acousto-Optic Spectrograph
(SAO), a multichannel acousto-optical receiver.
The sweep frequency analyser (ASG) covers
the full frequency band with a time resolution of 10
spectra/s.
The high sensitivity multi-channel acousto-optical
analyser covers
the 265-450 MHz range, with high frequency and
time resolution (100 spectra/s);
its recordings are used, mostly, for the study of fine
structures
1.2 to 1.6 GB/day

ARTEMIS IV
solar
radiospectrograph
operated by the University
of Athens at Thermopylae
Latitude 38 49' N,
Longitude 22 41' E
The observations last
nearly 9 hours and 40
minutes daily, which is
4 hours and 50 minutes
before and after local
noon

ARTEMIS IV
Franco-hellenic
Franco hellenic
Solar radio spectrograph
Thermopylae (OTE)
Greece
ASG 20-680 680 MHz, 10 spectra/sec
at 128 frequencies
SOA 250-450MHz, 250 450MHz, 100 spectra/sec
at 630 frequencies
1.4GB/day
X. Moussas, C. Caroubalos,
P. Tsitsipis, A. Kontogeorgos,
P. Preka-Papadema Preka Papadema A. Hillaris,
J.-L. L. Bougeret, G. Dumas, Dumas
V. Petoussis, Petoussis,
K. Bouratzis,
C. Alissandrakis

ARTEMIS IV
Parabolic
(7m diameter)
and
log-period antenna
The inverted V
antenna
Bill Ericson’s
design
(initially designed
for LOFAR)

The inverted V
antenna
Bill Erickson’s design
(initially studied for LOFAR)

after
a big solar flare, associated with a CME
Before the flare
magnetic
field
14th July 2000 flare
X-rays Halpha before after

PARABOLIC
ANTENNA
Antennas and cabin
Amplifiers
Filters
Amplifiers
Filters
System
Calibration
Circuit
Antenna
movement
Control circuit
DIPOLE
ANTENNA
20 – 100 MHz
Combiner
100 – 650 MHz
Signal 20 – 650 MHz
Coaxial line
Calibration Start - Stop
Multi pair telephone wire
Position control
Position Information
CABIN
S
A
B
C

October & November 2003 events
2003/10/26
05:57:00
07:33:00
06:54:00
X1.2
2003/10/28
09:51:00
11:24:00
11:10:00
X17

W / m 2
1E-3
1E-4
1E-5
1E-6
1E-7
G12(C3.2) , onset CME W
26/10/2003
Ha(SF) S17E49(486)
* onset CME NW *
* onset CME W *
Ha(SF) S16E50
II / IV (20-1200)
* onset CME E+ *
G12(X1.2) S15E44(486
0 2 4 6 8 10 12 14 16 18 20 22 24
UT
G12(M1.0) N05W33(484)
Ha(SF) S18E29(486)
Ha(SF) S09W44(483) , * onset CME Halo*
II (30-70)
G12(X1.2) N02W38(484
Ha(SF) N04W40
Ha(SF) N02W47
G12(M7.6) N01W38(484)

W / m 2
0.01
1E-3
1E-4
1E-5
1E-6
1E-7
Ha(SF) N08E08(488)
28/10/2003
G12(C5.3) N08E08 (488)
G12(C6.7) N03W55(484)
Ha(SF) N08E07(488)
G12(C7.5) S19E15(486)
Ha(SF) N08E07(488)
Ha(SF) N09E08(488)
Ha(SF) N08E07(488)
Ha(SF) N10E07(488)
Ha(SF)N08E07(488)
Ha(1F) N08E06(488)
G12(C7.7) N06W53 (484)
Ha(SF) N08E05(488) , Ha(SF) S11E00(489)
Ha(1F) N03W58(484) , onset CME NW
Ha(SF) N10E04(488)
onset CME SE
Ha(SF) S11W01(489) , Ha(SF) N06W56(484)
Ha(SF) N08E04(488) , Ha(SF) S20E08(486)
Ha(SF) S17E12(486)
G12(C8.7) N08E04(488)
Ha(SF) S17E09(486)
onset CME E, Ha(SF) N08E04(488)
Ha(SF) N08E03(488)
*** onset CME Halo ***
II / IV (25-180)
* G12(X17.2) S16E08(486) *
Ha(SF) S06E02(491)
0 2 4 6 8 10 12 14 16 18 20 22 24
UT
Ha(SF) S16E01(486)
Ha(SF) S16W01(486) , Ha(2F)N06W61(484)
Ha(SF) N07W02(488)
Ha(SF) S15E03(486)
Ha(SF) S15E03(486)
Ha(SF) N10W03(488)
Ha(SF) N10W03
Ha(SF) S15E03(486)
Ha(SF) N10W04

W / m 2
1
0.1
0.01
1E-3
1E-4
1E-5
1E-6
1E-7
Ha(SF) S20W63(486)
G12(X2.7) N10W83(488) , II / IV(20-850), onset CME
Ha(SF) S21W70(486)
Ha(SF) S21W71(486)
G12(X3.9) N08W77(488) , II/IV(25-180)
onset CME NW
Ha(SF) N09W79(488)
0 2 4 6 8 10 12 14 16 18 20 22 24
UT
G12(M3.9) S15W79(486)
Ha(SF) S15W79(486)
3/11/2003
onset CME SE
onset CME SW
G10(C4.4)
G12(C5.4)
G12(C3.1)

T h e 2 6 O c t o b e r 2 0 0 3
M A J O R S O L A R R A D I O B U R S T F R O M 0 6 : 0 0 T O 0 8 : 0 0 U T C
2 0
1 0 0
2 0 0
3 0 0
4 0 0
5 0 0
6 0 0
T h e b u r s t s ig n a l
0 6 : 0 0 0 6 : 2 0 0 6 : 4 0 0 7 : 0 0 0 7 : 2 0 0 7 : 4 0
T h e rad io ev e n t u s it is reco rd ed
2 0
1 0 0
2 0 0
3 0 0
4 0 0
5 0 0
6 0 0
T h e b u r s t L o g ( S ) s ig n a l
0 6 : 0 0 0 6 : 2 0 0 6 : 4 0 0 7 : 0 0 0 7 : 2 0 0 7 : 4 0
T h e lo g ( s . f . u . ) f o r t h e e v e n t 1 s . f . u . = 1 0 -2 2 W m -2 H z -1

20
100
200
300
400
500
600
4
3.5
3
2.5
2
1.5
1
0.5
x 10 -10
26 Oct 2004, final log(S) signal without background
06:00 06:20 06:40 07:00 07:20 07:40
0
06 :00 06 :20 06:4 0 07:00 07:20 07:40 08:00
-15
-16
-17
-18
-19
-20
-21
-22

20
100
200
300
400
500
600
28 Oct 2004, final log(S) signal without background
10:02 10:03 10:04 10:05 10:06 10:07 10:08 10:09 10:10
1.6 x 10 -9 The total signal flux density without background
1.4
1.2
0.8
0.6
0.4
0.2
1
0
10:02 10:03 10:04 10:05 10:06 10:07 10:08 10:09 10:10
-15
-16
-17
-18
-19
-20
-21

20
100
200
300
400
500
600
3 Nov 2004, final log(S) signal without background
09:48 09:50 09:52 09:54 09:56 09:58
16
14
12
10
8
6
4
2
0
x 10 -11 The total signal flux density without background
09:50 09:52 09:54 09:56 09:58
3 Nov 2004, integration time 0.5sec
-16
-17
-18
-19
-20
-21

Examples of ASG Dynamic Spectra
Top to Bottom
11 July 2000, 14 July 2000, 14 July 2000

Examples of ASG Dynamic Spectra
Top to Bottom
27 March 2000, 15 April 2000, 12 April 2000

ARTEMIS IV
SAO 28 October 2003

250 MHz
450 MHz
ARTEMIS IV, SAO spectra
We measure the slope (df/dt) of every burst and we
caclulate the speed of the electron beam which creates this
fiber burst (based on a model for the solar corona density).
We calculate the production rate of beams per minute, both
for beams leaving the Sun and returning back to the Sun
14th July 2000 flare and CME

Flare 14 th July 2000
1 hour of observations, 360000 spectra

Solar radio bursts
Flares and CMEs
Fiber bursts

Fiber bursts

Fine structure with LOIS also

F(V)
100
10
1
velocity distributions
of electron beams
leaving the Sun
(upper distribution)
and beams
returning back
(lower distribution)
14th July 2000
ARTEMIS IV
0 5000 10000 15000 20000 25000 30000 35000 40000
V in km/sec

F(V)
15
10
5
0
ARTEMIS IV spectroheliograph
outbound beams
inbound beams
0 5000 10000 15000 20000 25000 30000
velocity of electron beams in km/sec

velocities of beams in km/sec
14000
12000
10000
8000
6000
4000
2000
0
velocities of beams in km/sec
estimated with ARTEMIS IV data
10:49 11:39 12:29 13:19 14:09 14:59
time 14th July 2000

Velocity of outbound and inbound
electron beams in km/sec
30000
25000
20000
15000
10000
5000
0
ARTEMIS IV spetroheliographe
Thermopylae, Greece
average velocity
of outbound and inbound electron beams
assumed to produce the fibers
leaving the Sun or returning back
the four lines represent two models
for both outbound and inbound beams
9:56 10:16 10:36 10:56 11:16 11:36
time UT 17th April 2002

Based on Karlicky-Tlamicha-Newkirk for the coronal density

F(fiber bursts/minute) and ratio
120
100
80
60
40
20
0
ARTEMIS IV, Thermopylae
electron beams towards the earth
electron beams towards the Sun
10:49 11:39 12:29 13:19 14:09 14:59
time 14th July 2000
ratio of number of beams away
and towards the Sun
when the ratio > 1
indication of
reconnection ?

F(fibers/minute)
150
100
50
0
ARTEMIS IV spetroheliographe, Thermopylae, Greece
negative slope fibers
outbound electron beams
positive slope fibers
inbound electron beams
9:56 10:16 10:36 10:56 11:16 11:36
time UT 17th April 2002

ARTEMIS IV
ASG 28-10-2003

ARTEMIS IV
SAO 28-10-2003

ARTEMIS IV
ASG 23-10-2003

20 MHz
650 MHz

X3.9
2003/11/03
start 09:43:00
max 09:55:00
end 10:19:00

20 MHz 3 Nov 2004
650 MHz

STEREO/WAVES &
ARTEMIS

Fast Estimation of slopes
The Algorithm
•Applied to dynamic solar radio spectra obtained by ARTEMIS

Directional filtering -1
• A high-pass filter is applied to the
horizontal direction. As a result
continuous emission is rejected and
fine structure is revealed

Directional filtering –2
• The same high pass filter is applied to the vertical direction. As a
result vertical or quasi-vertical structures as pulsations are rejected
and intermediate drift bursts are revealed

FFT
• 2-D FFT is
applied to
filtered images.
Quasi – linear
structures in
dynamic spectra
produce quasi -
linear structures
in Fourier space

Coordinates transform
and Integration
• Fourier space is
sampled using bilinear
interpolation and
Angular power density
is taken by integration
along each radius

Slope Spectrum
• Slope spectrum is
the result of the
algorithm. Two
distinct peaks mean
existence of two
distinct groups of
fibers

Based on Karlicky-Tlamicha-Newkirk for the coronal density