Summer course 2018 - A Random walk in astro-physics
Professor G Srinivasan
Raman Research Institute (Retired)
The range of densities, temperatures, magnetic fields, etc. that obtain in the Universe are staggering: from 10-27 g cm-3 to 1015 g cm-3, from 3K to 1010 K, from 10-6 G to 1015 G. Not surprisingly, the variety of physical phenomena one encounters during the study of celestial objects is truly impressive. This set of lectures is intended to illustrate the richness of Astrophysics. It will be a random walk in basic physics, with numerous illustrations from astronomy. The topics in physics that will be reviewed have been chosen on the basis of their importance in contemporary astronomy.
Topics:
Absorption and emission of radiation
Radiation from relativistic electrons
Compton scattering of radiation
Spontaneous and stimulated emission
Hyperfine splitting of energy levels
Molecular spectra
Astrophysical plasma.
Quantum tunnelling.
Nuclear matter
Neutrino Oscillation
Phase transitions and the early Universe
During this random walk in physics, one will encounter a range of astronomical objects and phenomena, such as, Solar wind, gaseous nebulae, interstellar hydrogen clouds, giant molecular clouds, neutron stars and pulsars, supernova remnants, radio galaxies and quasars, active galactic nuclei, the cosmic microwave background, etc.
Schedule:
May - 16, 18, 23, 25 & 30
June - 1, 6, 8, 13, 15, 20, 22 & 27
Time:
10:00 AM
Venue:
Madhava Lecture Hall/ Emmy Noether Seminar Room
Table of Contents (powered by https://videoken.com)
0:00:00 Summer course 2018 - A Random walk in astro-physics
0:04:00 Introduction
0:05:39 Radiative transfer: absorption and emission of radiation
0:10:26 Principles of Radiative Transfer & Absorption and emission of radiation
0:11:50 The Sun we live in
0:12:09 Limb darkening of the Sun
0:14:40 Helium was discovered during the total eclipse of 1868 in Guntur.
0:18:58 Photon diffusion time
0:25:15 How hot is the Sun?
0:25:34 Virial Theorem
0:27:18 Virial Theorem applied to the Sun
0:30:42 Principles of Radiative Transfer
0:31:26 Specific intensity or Brightness
0:34:28 Emission coefficient
0:36:52 Absorption coefficient alpha v
0:40:15 Equation of Radiative Transfer
0:54:24 Planck Distribution
0:55:55 Wien's Displacement Law
1:04:06 Intensity from an optically thick body approaches the black body value.
1:07:40 Absorption and Emission lines
1:12:09 Emission lines
1:17:16 First law: A luminous opaque body emits radiation at all wavelengths, thus producing a continuous spectrum
1:17:57 Second Law: A rarefied luminous gas emits radiation whose spectrum consists of a series of bright lines, sometimes superimposed on a faint continuous spectrum
1:21:19 Black body radiation
1:26:46 Absorption Lines towards QUASARS
1:27:12 Primordial Hydrogen clouds
1:29:51 Lyman Alpha forest
1:30:34 QSO Absorption Line System
1:30:40 Usefulness of High Resolution
1:31:03 Measuring Abundances vs. Redshift
1:32:42 The remarkable discovery of the cosmic background radiation way back in 1940!
1:33:15 Mckeller (1940). Spectrum of star Zeta Ophiuci.
1:38:43 Next lecture: Spontaneous and Stimulated Emission of Radiation
1:39:01 Q&A