Πληροφορίες μαθήματος

Tο µάθηµα απευθύνεται σε µεταπτυχιακούς φοιτητές αλλά και προπτυχιακούς µε το κατάλληλο υπόβαθρο. O βασικός στόχος του µαθήµατος είναι η αναλυτική παρουσίαση εφαρµογών θεωρητικής αστροφυσικής σε θέµατα ακτινοβολίας. Συνιστάται ως προηγούµενη γνώση η Αστροφυσική Ι και ΙΙ (Φ-230, Φ-331) , καθώς και γνώσεις Σύγχρονης Φυσικής (Φ-201) και Κβαντοµηχανικής (Φ-303). Το μάθημα διδάσκεται στα Αγγλικά.

• Continuum Emission Processes. 3 particle distribution laws: Classical Maxwell-Boltzmann, Fermi-Dirac, Bose-Einstein; Radiative Transfer: optical depth, source function, mean free path; Thermal equilibrium: black body radiation, the Planck function; Brightness temperature; Four examples of radiative transfer: planetary nebulae, active galaxies, HI line emission, mbr; The Einstein Coefficients; Radiation from accelerating charged particles; The radiation equations (from Maxwell’s equations); Radiation from non-relativistic charged particles; Thomson scattering; Cyclotron radiation and bremsstrahlung; Radiation from relativistic charged particles – synchrotron radiation; Example: X-ray bremsstrahlung emission from clusters of galaxies. Interstellar absorption; Synchrotron radiation – detailed treatment and simple derivation; Polarized synchrotron radiation; Synchrotron self absorption; Luminosity and energy requirements of a synchrotron source; Equipartition, equipartition angular size, equipartition brightness temperature; Example – minimum energy of radio lobes of Cygnus A; Origin of power law energy spectrum; Thomson, Compton and Inverse Compton Scattering; A note on Spectral Index – comparison between synchrotron and inverse Compton spectra; Examples: synchrotron and inverse Compton emission from quasars; The inverse Compton catastrophe; Inverse Compton scattering by non-relativistic particles – the Sunyaev-Zel’dovich Effect; Example: Measurement of the ubble Constant from combined SZE and X-ray observations;
• Atomic Structure Key quantum mechanics results; The One-electron Atom; Atomic Wave Functions; Multi-electron systems; The Hamiltonian of a Complicated Atom; Ionization of Atoms; The Saha Equation; Example: An interesting example in astrophysics; Multipole fields and the fine structure constant
• Spectral Line Emission Processes Radiative transitions (non-matrix and matrix approaches); Collisional transitions; HI 21 cm radiation; Molecular structure and diatomic molecule emission; Example: CO emission