Measuring Proton Energies and Fluxes Using EIT (SOHO) CCDs Areas Outside the Solar Disk Images

1. Measuring Proton Energies and Fluxes Using EIT (SOHO) CCDs Areas Outside the Solar Disk Images L. Didkovsky1, D. Judge1, A. Jones1, and J. Gurman2 1USC Space Sciences Center 2 Goddard Space Flight Center

2. We Propose • To use SDO CCD areas outside the solar disk images for extracting information related to proton energies, fluxes, dynamics, asymmetries, etc., for SEPs associated with powerful CMEs and X-class flare events. The typical proton energy ranges above 40 MeV (SOHO/EIT data) are substantially narrower than available from the GOES database, e.g., 45 – 49, 145 – 154, 195 – 234, 297 – 335, and 390 – 440 MeV. SDO CCDs may allow us to extract SEP data with a substantially higher cadence than EIT and in a number of narrower energy ranges using a differential technique.

3. Why We Propose To Study SEPs “Why haven’t we made more progress in understanding SEP events?”, - T. von Rosenvinge (Chapman Conference on Solar Energetic Plasmas and Particles, 2004, Finland) • Relation to solar flares and CMEs? • Acceleration mechanisms: when and how they work? Shock waves / Magn. Reconn., D.E. Innes, Nature, 1997 • Relativistic properties? • Details of energy spectra? • Isotropic vs. anisotropic (e.g. ERNE event of 1996/07/09: 25-40 deg FWHM)?

4. How To Study SEPs • GOES-8,10,11 database (40, 80-165, 165-500 MeV). • ERNE/SOHO (saturated by extreme events). • A Project based on a few space platforms, observing SEPs at different distances to the Sun (B. Lin “The living with a star (LWS) sentinels mission”, SPIE 5901, 2005), is under development. • Extract SEP fluxes and proton energies in a number of narrower (than GOES) energy ranges (current work). E.g., Didkovsky et al. Astron. Nachr. / AN, 327, No.4, 314, (2006).

5. Extracting Proton Events (Jan 20, 2005) Original SW area Of 128 x 128 pix S One-pix events Intensity shows proton deposited energy W E NOAA 10720

6. One-pixel Events and CCD Deposited Energy Angles of incidence (spatial areas) to create one-pixel events into 21x21x12 m EIT CCD

7. Energy Ranges E (MeV): • 45-49 (47) • 145-154 (150) • 195-234 (220) • 297-335 (316) • 390-440 (415)

8. GOES and EIT Proton Spectra The largest low-energy flux and the largest trend: 10/28 The largest high-energy flux, the smallest trend, and the smallest time delay from the X-ray peak: 01/20

9. Bastille Day SEPs Extracted From EIT An example of extracted from EIT (thick lines) proton fluxes in four energy ranges of 47, 150, 316, and 415 MeV compared to the GOES (thin lines) database. Dotted line shows GOES X-ray flare profile for reference in arbitrary units. Some dropouts are due to a low statistics of the SEP events.

10. Time-delays Vs Energy

11. Proton Flux Anisotropy (Ratio One-pix/other) 10:48:10 (415 MeV) Concentration in space/time 11:00:10 (415 MeV) 47 MeV

12. Proton Flux Anisotropy Wind Satellite data (http://lepmfi.gsfc.nasa.gov/mfi/) Concentration in space Concentration in time

13. Conclusions • Extracting proton energies and fluxes from EIT CCD areas outside the solar disk images is a new and powerful tool for our better understanding of SEP generation, acceleration, and relation to the solar flares. • A modeling of proton energy deposition / stopping power for a number of SDOCCDsmay be started now if there is a strong interest in converting the “painful noise” of the solar observations into important knowledge about SEPs. • Software developed to extract SEP-associated events from SDO CCDs may be used to clean up the solar images from the particle-related noise.