Solar-B domestic meeting
2005.10.31

Solar-B/EIS high-cadence observation for
diagnostics of the corona and TR

S. Kamio (Kyoto Univ.)
E-mail: kamio@kwasan.kyoto-u.ac.jp

Chromospheric evaporation• High energy particles generated in theflare penetrate into the chromosphere.
• Explosive heating in the chromosphere• Hot plasma (107K) is supplied into thecoronal loop
(Neupert 1968, Hirayama 1974)

Schematic modelHigh energy
particle• Down flow and up flow should beobserved in different temperature range.
Spectroscopic observationin many linesCoronaChromosphereFlare observed with SOHO/CDS(Kamio et al. 2005 ApJ 625, 1027)• Observed 4 flares (GOES B–M class) with SOHO/CDS andHida/DST• Impulsive downflows (60–80km/s) in the transition region(105K) in flare kernels.

Evaporation model
downflow• Velocity behavior
depends on energy fluxof non-thermal electrons.
(independent of totalenergy)• High speed flow can beobserved in a small flare( < GOES C class)• high resolution of EIS
enables detection ofsmall events

upflowgentle
F = 109(erg/cm2/s)

explosive
F = 5x1010
Fisher et al (1985)

Velocities and temperature
TCa XIX (107 K)

250km/s component (Wülser et al. 1994)

Fe XIX (8x106 K)

Upflow component (Brosius 2003)

Fe XVI (2x106 K) No significant flow (Teriaca 2003)
Mg IX (106 K) No significant flow
O V (2x105 K) 50-80km/s(Kamio et al. 2005)

He I (4x104 K) 10-20km/s• Solar-B/EIS can simultaneously observe
these velocities.

Network structure• Network magnetic field must be
important in terms ofconnection between thephotosphere and the corona• Origin of EUV blinkers andexplosive events?
• De Pontieu (2004)
Inclined field cause wave
leakage into the corona.
• Zhang et al (2000)
Macrospicule were triggered byinteraction of magneticelements

Image: Hα –0.6Å
Contour: OV intensity

Strong emission lines for EIS• Wide temperature
EIS DN* (sec-1 )Ionlog Te λ (Å)
range (105-107K)
QR AR
Flare
 Good diagnostics
He II
4.7 256.3 276x103in coronal temperature
OV
5.4 192.9 0.517x102• Better spatial andMg VI
5.6 270.0 165x102
spectral resolutionFe XII
6.1 195.1 30 6x10 7x103
2
 small events
 line broadening
Fe XXIV 7.3 192.0 004x105*Counts (with 2"x2" binning) estimated by CHIANTI 5.1• Desired count: 50(Dere et al. 1997, Young et al. 2003)(velocity error < 10 km/s)
Corona (106K): 1 sec
Transition region (105K): 10 sec• SOT(NFI) or ground-based telescope is needed forchromospheric velocity (Hα, or Mg I)

Example• Active region dynamics
5 spectral lines (16 pixel width)
Exposure: 10 sec
FOV: 10” x 512” (5 step)Cadence: 1 min

Data rate(no compression) 32 kbps
Long 512” slit can cover bothactive and quiet regions• Flare5 spectral lines (16 pixel width)
Exposure: 1 sec
FOV: 1” x 128” (sit-and-stare)
Flare detection by XRTor EIS (slot observation)

Data rate(20% compression) 32 kbps

Imager v.s. spectrometer• Cooperation with EUV imager is necessary(TRACE or STEREO)

Synthetic spectraPeter, Gudiksen, and Nordlund (2004)• 3D simulation of coronal braiding (current dissipation)

Statistical properties

Peter, Gudiksen, and Nordlund (2004)• Statistical properties (e.g. average, deviation) aregood tests for the theory.
• Coronal heating model must explain the persistent
red shift in the transition region• Solar-stellar connectionTemperature and ionization• Wide temperature
range can be studied
by using different
emission lines.

Temperature and ionization of oxygen
Mariska The solar transition region

SOHO/SUMER• Good diagnostics in the chromosphere and thetransition region (104 – 106 K)

STEREO (Solar TErrestrial RElations Observatory)• Observe 3D structure of the Earth-directed CME(A pair of spacecraft)• Launch 2006
• EUV Imager (1.6”/pixel)
Full Sun in 171Å, 195Å, 284Å, 304Å• Coronagraph
COR1 1.1 - 3.0R
COR2 2 - 15R• Heliospheric Imager
Interplanetary CME
http://stereo.gsfc.nasa.gov/

SDO (Solar Dynamics Observatory)• Observe fine magnetic structures• Launch 2008
• HMI (Helioseismic and Magnetic Imager)
Full Sun Doppler velocity (1” resolution)
Vector magnetic field measurement• High resolution imager (0.6”/pixel)
7 EUV and 3 UV bands
Full Sun (FOV 41’ )• EUV irradiance measurement

http://sdo.gsfc.nasa.gov/

Solar Orbiter• Getting close to the Sun (45R or 0.2AU)• Launch 2013 ?
• Instruments (TBD)
soft X-ray, visible light
EUV imager/spectrometer• High resolution0.5” = 70km (at 0.2AU)• Polar region observation
Latitude up to 33 degree

http://www.orbiter.rl.ac.uk/

Future solar missions• Demands for better spatial and temporal resolution(in terms of coronal heating)- small scale magnetic structures- wave or oscillation• “Golden age” continues
Solar-B (2006)
STEREO (2006)
Solar Dynamics Observatory (2008)
Solar Orbiter (2013 ?)Solar-C ?

• We should understand their capabilities andlimitations to make a suitable observational planTemplate• Item