From last time: M87 Counterjet

• M87 an the amazing one-sided jet
• radio evidence from inner jet: Kovalev et al (2007)

Cosmic Rays

Basic Properties

• What are cosmic rays?
  • solar energetic particles
  • Galactic
  • extragalactic
• in real time: data from ACE
• spectra: ions, electrons
• composition
• acceleration site--supernova remnants: SN1006, E0102-72
• propagation: cosmic-ray electrons in the Milk Way: radio continuum 408 MHz sky; in other galaxies: radio halos in NGC5775 and NGC 253 radio vs optical
• experiments:
  • balloon-borne: CREAM, CAPRICE-2
  • space-based: ACE ATIC, Fermi
  • ground-based (atm Cerenkov): H.E.S.S., VERITAS
  • ground-based (air shower): AGASA, HiRes, Auger

Synchrotron Radiation

Relativistic Motion in a Uniform Magnetic Field

• gyrofrequency
• gyroradius
• implications for ordinary cosmic rays and those with high and for ultra-high energies

Synchrotron Emission

• emitted power
• emitted spectrum

Synchrotron Self-Absorption

Awesome Example: Supernova Remnants

• SN 1572 (Tycho) radio synchrotron movie
• SN 1054 (Crab) multiwavelength

Awesome Example: Radio Galaxies

• radio galaxy Cygnus A
• Centaurus A: image; spectrum