1. Planning Flare Observations for Hinode/EIS
Ryan Milligan
NASA/GSFC

2. EUV Imaging Spectrometer (EIS)
CDS
Exposure times 1s
10s
Raster cadence
3 mins
11 mins
FOV
512"x360"
240"x240"
Temp range MK MK
Doppler resolution
3 km/s
15 km/s
Spatial resolution
1 arcsec
4 arcsec

3. Rastering

4. Observing Study Selection
Line selection
Short wavelength channel: A
Long wavelength channel: A
Slits or slots
1" and 2" slits
40" and 260" slots
Exposure times
1-30 seconds
Raster or ‘sit and stare’
Field of view
Up to 512"x256"

5. EIS studies http://msslxr.mssl.ucl.ac.uk:8080/SolarB/EisStudyList.jsp
325 studies (1-Dec-2008)
QS, AR, Flare, CH, Filament, Engineering
Only 5 of these are designed specifically for flares (1.5%)

6. CAM_ARTB_RHESSI_b_2 40143 FOV 4 minute raster cadence
10 second exposure
Wide range of emission lines:
He II
O IV, V, VI
Mg V, VI, VII
Si X (density sensitive pair)
Ca XVII
Fe VIII, X, XI, XII, XIII, XIV, XV, XVI, XVII, XXIII, XXIV

7. RHESSI keV

8. RHESSI keV

10. Velocity vs. Temperature

12. Max Millennium Major Flare Watch
SOHO/CDS
Hinode/EIS ?
ACTIVITY: To be run with TRACE/EIT/MDI/RHESSI. Continuous tracking of a flare-producing active region. When an active region has a high probability of producing a large flare, a Major Flare Watch is likely to be called by the RHESSI team. As much time as possible should be devoted to the flare watch.
STUDIES TO BE RUN: Begin with one ARDIAG_2 (ID 11 , var. 98), and follow with many FLARE_AR (Study ID 173, var 9), 3x3 arcmin field. Follow with solar rotation, modifying the pointing once per hour (or when the pointing change is approx. 10 arcsec). Repeat FLARE_AR for several hours. If short of time, run only FLARE_AR.
POINTING: Pointing coordinates are sent out each day by the Max Millennium team. The CDS planner receives these s.
DURATION: A few hours per day, when run. It may be continued for longer if the flare activity and chances of recording a flare are high.

13. X-band downlink problem
At the end of 2007, X-band transmitter signal began to experience irregularities in the latter half of each contact with the ground station.
Irregular signal has caused partial and complete loss of science telemetry data.
Primary downlink path was switched to S-band transmitter in March 2008
256 Kbps, instead of 4 Mbps with X-band.

14. Current telemetry restrictions
Telemetry divided between 3 instruments
SOT 70%, XRT 15%, EIS 15%
Telemetry volume reduced to 20-50% after X-band problem
For EIS currently
~500 Mbits per day.

15. EIS flare observations require large data volumes
EIS flare observations require large data volumes. Sample study: CAM_ARTB_RHESSI
21 windows, 40”x140” FOV, 4 minute cadence, no comp.
Datarate of 58 Kbps, could be run for 2.5 hours!!
Possible solutions for running similar study during high activity periods (>12 hours per day)
Need to ‘borrow’ SOT telemetry
More ground stations coming online
Reduce number of lines, cadence, FOV, etc.
Data buffering - overwrite non-flaring data
Compress data

16. GOES lightcurve with RHESSI and Hinode orbits

17. Generic Study FOV: 80”x120” Comparable to moderate sized AR
Raster cadence: < 5 minutes
Exposure times: 5 seconds
Line selection:
Fe X, Fe XII, Fe XV, Fe XXIII, Fe XXIV
Density sensitive lines
Need Target Of Opportunity
Track active region for > 12 hours per day
Flare trigger mode may miss impulsive phase
Study must be science-driven
What are the outstanding issues?
How can EIS be used to answer them?

18. Outstanding Issues…
How does emissivity of upflowing material vary w.r.t. velocity and temperature (VDEM)?
Momentum balance between up- and downflowing material
Upflow velocity as a function of time
beam driven versus conduction driven?
How do electron beam parameters affect the evaporation process?
Density variations/enhancements using line ratio techniques
Thermal/nonthermal line broadening
Why are the hottest lines predominantly stationary?
Reconnection inflows? Coincident with coronal HXRs? …

20. Outline Introducing EIS… Creating EIS studies
Chromospheric Evaporation using EIS
Outstanding questions on solar flares
The X-band problem