Radiation Processes
Absorption Processes
Photoionization
Example of photoelectric absorption
How much passes through?
PPT Slide
Integrating over length from source...
Optical depth
Column density
Clumping of the ISM
Smooth versus clumpy
Numerical example
Electron scattering
Thomson Scattering
Thomson scattering cont.
Compton scattering
Compton scattering cont.
Electron-positron pair production
Minimum g-ray energy required
Calculating the minimum energy
And this is...
Minimum energy for mm-wave photon
Photon-nucleus pair production
Photon versus particle density
Synchrotron Self-Absorption
Synchrotron Spectrum
Blackbody turnover
On the Rayleigh-Jeans side...
Total flux at Earth...
SSA spectrum
Source distance
… and SSA frequency
SSA in Compact X-ray sources
Radiation processes (summary)
Electron energies required
Inverse Compton Scattering
Non-thermal process (cont.)
Ratio of IC to Synchrotron Xrays
Ratio IC to Synchrotron (cont.)
X-rays from IC scattering
IC - starlight versus 3K
IC or synchrotron for X-rays?
Synchrotron emission
Email: emp@mssl.ucl.ac.uk
Home Page: http://www.mssl.ucl.ac.uk/