Bremsstrahlung: Free-Free Emission

• Order of Magnitude Expectations
• Theory: Classical, Non-Relativistic Case
• thermal bremsstrahlung
• self-absorption spectrum from here
• awesome example: intracluster medium
  • galaxy clusters seen in optical light: Virgo, Coma, Abell 1689
  • intracluster medium seen in X-rays: Virgo here and here, Coma, Abell 1689
• awesome example: supernova remnants
  • Cas A: Chandra X-ray image, spectrum
  • SN 1006: Chandra X-ray image, spectrum
• awesome examples: eROSITA sky and bubbles; compare gamma-raay Fermi bubbles and microwave WMAP/Planck haze