1. Physics 777 Plasma Physics and Magnetohydrodynamics (MHD) Instructor: Gregory Fleishman Lecture 13. Astrophysical Plasmas 02 December 2008

2. Plan of the Lecture Strong Energy Release in the Plasma Collimated Jets Bulk Relativistic Motion of the Plasma More Examples of the Plasmas in Astrophysical Objects

3. Section 1. Strong Energy Release in the Plasma. Examples. Release of the magnetic energy: flares in accretion disks, solar/stellar flares: ~10 32 erg Nuclear energy release: Nova (~10 46 erg ) and Supernova Ia (~10 51 erg ) explosions Gravitation energy release: core-collapse Supernova explosions (~10 51 - 10 52 erg ) and accretion of the gas on the black hole.

4. Credit: Y. Uchiyama, 2008

11. Section 2. Collimated Jets

12. Observations of M87 Shocks?

13. Accelerated particles emit waves at shocks Schematic GRB from a massive stellar progenitor (Meszaros, Science 2001) Prompt emission Simulation box

14. Temporal Variability dT 100dT 100

15. dT ~ 1ms  R < 310 7 cm E ~ 10 51 ergs  10 57 photons high photon density (many above 500 keV). Optical depth  T n R~10 15 >>1 Inconsistent with the non thermal spectrum! COMPACTNESS PROBLEM  e + + e - Spectrum: Optically thin Size & Energy: Optically thick ? Paradox ?

16. A C B D R R R  ~1/   Relativistic Time-Scales t B -t A ~ R (1-  ) / c ~ R/2  2 c t C -t A ~ R(1-cos  )/c ~ R/2  2 c t D -t A ~  /c

17. n Due to Relativistic Motion R =  2 c dT E ph (emitted) = E ph (obs) /    =   n  T R ~ 10 15 /   (Goodman; Paczynski; Krolik & Pier; Fenimore; Woods & Loeb;Baring &Harding; Piran & Shemi; Lithwick & RS)  The Solution: Relativistic Motion

18. 1. Doppler frequency shift 2. Directivity and aberration

19. 3. Superluminal motion Source Observer

20. Section 4. Other examples. Pulsar wind nebulae

21. 3C 58

22. Credit: Chandra/HST Crab nebula

23. Credit: R. Ong, 2004

24. Section 7. Homework Oral presentation file, due 12/07/2008.