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High energy Astrophysics Mat Page Mullard Space Science Lab, UCL Revision lecture.

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Presentation on theme: "High energy Astrophysics Mat Page Mullard Space Science Lab, UCL Revision lecture."— Presentation transcript:

1 High energy Astrophysics Mat Page Mullard Space Science Lab, UCL Revision lecture

2 Revision lecture: This lecture: Quick race through the course! Intended to inspire you to look back through your notes!

3 1: What is high energy astrophysics? High energy because: –Photons emitted above 100 eV (X-ray sources) –Large energy density in photon field or magnetic field, (eg X-ray binaries, pulsars) –Large amount of energy stored in gravitational field (eg Black holes) Unusually high concentrations of energy

4 X-rays from stellar photospheres? Take the Sun. T=5800K XUIV R

5 X-ray, -ray and radio skies

6 2: The whole range of X-ray sources

7 3: emission mechanisms

8 4+5: accreting X-ray binaries

9 accretion efficiency How much energy can we get from accretion compared to fusion? Energy released per unit mass of material accreted = GM/R Energy equivalent per unit rest mass = c 2 So we can consider the efficiency of accretion to be GM/(Rc 2 ) For a white dwarf this is ~ 1.5 x Fusion of hydrogen converts of rest mass to energy so we could say this has an efficiency of 0.7%

10 6: radio galaxies e.g. Faranoff-Riley 1 galaxy

11 shell-like filled in Cas A Crab 7: supernova remnants

12 8: AGN

13

14 9: The X-ray background

15 Coma cluster 10: Masses of hot gas

16 11: Gamma-ray bursts

17 Burst lightcurves

18 12: Cosmic rays

19 13: Gravitational waves

20 14: The Galactic centre

21

22 15: The future!


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