1. High Energy Observational Astrophysics

2. 1 Processes that emit X-rays and Gamma rays

3. High Energy Observational Astrophysics 2 Sources: ????

4. High Energy Observational Astrophysics 3 Problems with Earth based observation

5. High Energy Observational Astrophysics 4 Early attempts to measure X-ray and gamma ray spectra

6. High Energy Observational Astrophysics 5 Interactions of photons with matter: ????

7. High Energy Observational Astrophysics 6 Different kinds of detector: ????

8. High Energy Observational Astrophysics 7 Imaging detectors to record path

9. High Energy Observational Astrophysics 8 Satellite observatories

10. High Energy Observational Astrophysics 9 Neutrinos: sources, interactions, detectors

11. High Energy Observational Astrophysics 10 Gravitational waves

12. High Energy Observational Astrophysics 11 Cosmic Ray Particles

13. 1) What is black body emission?

14. X-rays and gamma rays X-rays from about 0.12 keV to 12 keV are “soft” X-rays X-rays from about 12 keV to 120 keV are classified as "hard" X-rays Gamma rays range from about 120 keV to 30 MeV

15. Thermal Bremsttralung A charged particle undergoing an acceleration radiates photons. Bremsstrahlung radiation is emitted by a charged particle accelerating under the influence of another charged particle, losing kinetic energy. Rate of acceleration determines wavelength of radiation produced. Greater acceleration produces smaller wavelength emission. In hot plasma at temperature T the free electrons are constantly producing Bremsstrahlung radiation during interactions with the ions.

16. Synchrotron radiation Similar to Bremsstrahlung radiation, but charged particles are accelerated (either in a straight line or around a circle) whereas in the latter they deflect from other charged particles (usually ions). Most common example: electrons in a magnetic field spiral around the field lines emitting radiation. The frequency of the radiation depends on the strength of the field and the component of the electrons motion perpendicular to it.

17. Who are the usual suspects? Type II Supernovae Emit around 10 46 joules (more than the Sun will emit in its entire lifetime) If a main sequence star has a mass of over 8 times the mass of the Sun it is destined to be a type II supernova As the density rises protons and electrons collide to form neutrons and a vast number of neutrinos. Nuclear fusion continues until Fe at centre, stops, star collapses increasing temperature and pressure. Eventually a neutron star is formed if the core is less than three solar masses. More than this and a black hole forms. Nucleosynthesis occurs in core and advancing shockwave. H emission lines are also produced by advancing shockwave.