GALILEO MEETING Nobeyama 10/11 July, 2002 UK BCS PRESENTATION

1. GALILEO MEETING Nobeyama 10/11 July, 2002UK BCS PRESENTATION Len Culhane Mullard Space Science Laboratory University College London

2. SUMMARY • Brief history of BCS concept • Summary of instrument properties • Some scientific highlights • People involved in Galileo project • Proposed contribution from BCS team

3. Original BCS Prototype Flown on NASA Aerobee Sounding Rockets Prototype used a curved KAP crystal and operated in the range 8 – 17Å. It obtained solar active region spectra with several strong Fe lines. Demonstration of BCS operation led to its selection as part of the X-ray Polychromator instrument, with L.W. Acton as PI, on NASA’s Solar Maximum Mission First results from the prototype published in: "A New Type of Crystal Spectrometer for Solar X-ray Studies", J.L. Culhane, R.C. Catura, E.G. Joki, J.C. Bakke and C.G. Rapley, 1974, Mon. Not. R. astr. Soc., 168, 217.

5. Mounting of the BCS in Yohkoh

8. Plasma Upflow Velocities for Flare of 16 December, 1991 (Culhane, Inda, et al., 1994, Solar Physics) Velocities are determined from two component fits to the Ca XIX resonance line profile High velocity flow is initiated following energy deposition by non-thermal electron impact in the Chromosphere. Hard X-ray burst light curve profiles the electron beam impact. Plasma upflow occurs during and just after the hard X-ray burst but the upflow velocity returns to the AR value after the peak of the Ca XIX light curve

9. Evolution of Ca XIX Resonance Line Profile for the Flare of 16-12-91

10. Evaporation and the Slope of the Accelerated Electron Spectrum (McDonald, Culhane, Harra, 1999, Sol. Phys.) Accelerated electron spectrum: dN/dE = kE-g Steep spectrum leads to enhanced evaporation g = 4.0 g = 3.0 _____ Total Energy -------- Evap. Energy 2nd February, 1992 16th December, 1991

11. Line Broadening and Non-thermal Velocity For a limb flare there can be no line of sight velocity components. Vnt = [2k (TLW - Te)/M]0.5 = 0 for TLW = Te Yohkoh BCS Ca XIX impulsive phase spectrum is illustrated. Excess width (TLW>Te) above the thermal Doppler value could be due to turbulence inupflowing plasma or directly related to energy release. (Khan et al., Ap. J., 1995)

12. Pre-flare Development of Vnt in AR 7590 on 3 Oct., 1993 (Harra, Matthews, Culhane, 2001, Ap. J. Lett.) HXT SXT HXT SXT Flare A Flare B BCS S XV Spectrum HXT and BCS S XV Light Curves

13. Vnt and HXT (15 – 25 keV) plotted against time for two Flares on 3 Oct., 1993 (Harra et al., 2001) Vnt falls after flare A to a minimum of 40 km/s at 09:13 UT. This value is characteristic of active region plasma. Flare A Flare B Vnt It then rises steadily over 11 min. to reach ~ 100 km/s at 09:25 UT - the start of hard X-ray emission by flare B. HXT There is evidence for pre-flare B magnetic flux emergence in AR 7590

14. Coronal Plasma Parameter Scaling with Photospheric Magnetic Field (van Driel-Gesztelyi et al. ) Tests of Heating Models (Demoulin et al.) The evolution of AR 7978 has been studied over five rotations from birth to decay Only AR 7978 was present, so BCS was used to measure plasma parameters as was SXT. Spectra show Te evolution MDI measured total magnetic flux for emergence and six CMPs Observations show <T>AR and <EM>AR = a Bavb. Values of b were established for <T>, <EM>, <n> and <p> that are consistent for BCS and SXT. Models allowed by the range of exponents favour magnetic field stressing models rather than those based on wave heating

15. People Involved MSSL NRL • Bentley - Brown • Culhane - Doschek • Foley - Mariska - Harra RAL NAOJ - Lang - Watanabe

16. Summary of Proposed BCS Contribution - I • BCS data in agreed FITS Format • Input to Legacy book: • Full instrument description • Updated instrument guide • Report on instrument calibration • Spectral fitting routines with comments • Summary of discoveries with major BCS role • BCS contribution to a mission-wide bibliography

17. Summary of Proposed BCS Contribution - II • BCS spectra – photon units vs wavelength • BCS SXV and Ca XIX time spectrograms – one per orbit • BCS flare catalogue that matches GOES event list above a “tbd” threshold • In flight cal data – approx 10 calibration data sets through the mission

18. Spectrogram – approach I Time Wavelength

19. Spectrogram – approach II

20. Interaction with UK SURF and European Grid of Solar Observatories (EGSO) • The Solar UK Research Facility (SURF) is the new name for Yohkoh Data Archive Centre (YDAC) • UK BCS Galileo activities will be organized within SURF • There is also a UK ASTROGRID project with solar data involvement – SURF will maintain contact with ASTROGRID • Galileo FITS headers should ideally be compatible with EGSO catalogues • EGSO FITS headers should contain certain key words • The EGSO project is at an early stage and seeks a continued dialog with Galileo - RDB is interacting with the Galileo FITS working group • Continuing dialog is sought in particular on data provision, access and related security issues • A draft FITS header document has been distributed to the attendees at this meeting

21. END OF PRESENTATION

22. Pre-flare Development of Vnt in AR 7590 on 3 Oct., 1993 (Harra, Matthews, Culhane, 2001, Ap. J. Lett.) HXT HXT SXT SXT Flare A BCS S XV Spectrum Flare B HXT and BCS S XV Light Curves