
RELATIVISTIC ASTROPHYSICS
Second cycle degree in PHYSICS
Campus:
PADOVA
Language:
English
Teaching period:
Second Semester
Lecturer:
ROBERTO TUROLLA
Number of ECTS credits allocated:
6
Prerequisites:

Classical electrodynamics, special relativity, general astronomy and astrophysics 
Examination methods:

Oral examination 
Course unit contents:

Compact objects. Late stages of stellar evolution, corecollapse supernovae. White dwarfs, neutron stars and black holes.
General relativity. The vacuum Schwarzschild solution and its properties. Geodesic motion in the Schwarzschild spacetime. Interior Schwarzschild solution, hydrostatic equilibrium configurations, the TolmanOppenheimerVolkoff equation. The Kerr solution (basics).
Degenerate systems. Quantum statistics (brief overview). Equation of state for a completely degenerate gas; the nonrelativistic and ultrarelativistic limits. The Chandrasekhar mass.
Matterradiation interaction. The radiation field. Emission, absorption and scattering. The radiative transfer equation. Optical depth. Simple solutions to the transfer equation: radiative diffusion and free streaming. Radiative processes: electron scattering and freefree. The Eddington limit.
Accretion onto compact objects. Spherical accretion, the BondiHoyle solution. Compact objects in bynary systems. The Roche lobe geometry. Wind and Roche lobefed accretion. Accretion discs. The standard disc model (alphadisc). Radiation spectrum from an alphadisc.
Neutron stars. Magnetic field and rotation. Magnetorotational braking and the period evolution. Estimate of the magnetic field and of the age from the period and the period derivative. The PPdot diagram. Magnetosphere, light cylinder. GoldreichJulian currents. The Alfven radius, column accretion onto magnetized neutron stars. Internal structure of a neutron star. Neutronization. Neutron star cooling. Neutrino cooling, URCA and modified URCA. Radiative cooling. Cooling curves. 

