1. Searching for Solar Shocks Including a brief history of X-ray astronomy H. Hudson, SPRC/UCSD/ISAS

2. Beautiful Chandra shock (E0102-72)

3. How X-ray astronomy began September 21, 1859 (Carrington) Kew Gardens - magnetic effects The proper conservatism of L. Kelvin of Largs

6. Latent discoveries X-rays (Roentgen, 1895) The ionosphere (Heaviside, 1902) Collisionless shock waves - ? “Space weather” - ??

7. Oliver Heaviside Maxwell’s equations Laplace transforms The Heaviside function Telegraph equation - Pupin Laboratory Heavy opposition to quaternions T.S. Eliot, Cats, “Journey to the Heaviside Layer” Not the father of X-ray astronomy (due credit to B. Rossi, of course) “Why should I refuse a good dinner simply because I don't understand the digestive processes involved.”

8. We’re in a golden era of coronal observation

10. The dynamic corona

12. The boundary between Photosphere and corona Density plummets precipitously Collisionality diminishes Radiation decouples Plasma beta drops drastically

13. Height in corona T B 0 T.R.

15. Solar shock: Type II burst

16. A Type II burst is the same thing as a “slow drift” burst - perhaps discovered by early military radars; explained by J. P. Wild and Y. Uchida Time Wavelength III II (recall -2 ~ n e )

17. Meter-waves and soft X-rays Megahertz vs Exahertz Radiative transfer vs direct view Magnetic effects vs Bremsstrahlung Inherent fuzziness vs sharp resolution But - by 1998, we’d seen Types I, III, IV and others

18. But not the simplest and most obvious: Type II!

19. X-ray observation of a global wave Wave propagation tells us about coronal structure The innermost (earliest) motions tell us about the flare process itself

20. Moreton-Ramsey wave and EIT wave

21. Why didn’t SXT discover “SXT waves”? SXT views the whole corona Fast-mode MHD waves must involve compressional heating SXT response increases monotonically with temperature So… why did it take 8 years and the competitive example of EIT?

22. Factors abetting wave detection in soft X-rays The wave needn’t be shocked The SXT response strongly favors detection of a temperature increase (adiabatic law)

23. Sensitivity estimation R i (n,T e )=const£n 2 e £S i (T e ), @(ln(R i )) @(ln(T e =¢ i (T e )=3+ d(ln(S i d(ln(T e,

25. SXT and TRACE responses Courtesy N. V. Nitta

26. Factors reducing sensitivity Poor CCD dynamic range (AEC) Limited SXT telemetry(“Velocity filter”) Photon counting statistics Scattering from grazing-incidence mirror Flare mode

29. May 6, 1998 FOV 10 arc min

30. FOV 5 arc min

33. Gas pressure in flare loops

35. SOHO/ EIT

36. Uchida’s 1968 model

37. S.W. Uchida A.R.

38. OK, so what caused the wave? In principle we can see it all in soft X-rays The earliest manifestation of the wave is within 20,000 km of the flare core But… it is significantly displaced from the soft X-ray core of the flare

40. Mysteries of low  plasma Everything seems to expand (cf. Aly) The Virial Theorem looks goofy too

41. Implosion conjecture At low , the coronal energy is purely B 2 /8  During a flare, there’s no time for energy transport through the photosphere Therefore, some field lines must shorten

42. Isomagnetobars Closed field lines Open field lines How low-  implosions must work

43. MHD Virial Theorem

44. The end, thanks