765649S
Astrophysics
an advanced course (10 credits)
at the Space Physics and Astronomy research unit, University of Oulu
The course period: January 10 – April 26, 2024
Lectures, exercise and practical sessions take place usually on Monday, Wednesday, and Thursday at 14-16, see Peppi for detail. However, classes on Thursday will only occur when I announce them!
The course is lectured in English
Teacher: Vitaly Neustroev, MA 308, vitaly[-at-]neustroev.net
Course plan:
- Stellar structure and evolution
- Radiative processes
- Stellar photospheres
- Interstellar Medium
- etc…
Theoretical and practical considerations will be supplemented with the home exercises which constitute the important part of the course.
Literature:
Textbook choice for this course is largely a matter of personal taste. I provide below a list of recommended books. Study them in parallel with the lectures.
- Stellar Structure and Evolution – Onno Pols, Utrecht, 2014 (Free)
- An Introduction to the Theory of Stellar Structure and Evolution – Dina Prialnik
- Introduction to Stellar Astrophysics: Vol 2 – E. Böhm-Vitense
- Introduction to Stellar Astrophysics: Vol 3 – E. Böhm-Vitense
- Observations and analysis of stellar photospheres – D. F. Gray [E-Book]
- Lecture notes (Part I) – not enough!
- Lecture notes (Part II) – not enough!
- Lecture notes (Part III) – not enough!
Schedule
- Lecture 1: January 10: Introduction (What is Astrophysics and Theoretical Astrophysics? Astronomical units). Stars (Role of stars; Definition; What can we learn from observations?).
PDF - Lecture 2: January 11: Stars (Properties of stars; Stellar timeline; basic assumptions, mass conservation, hydrostatic equilibrium).
PDF - January 15: NO CLASS
- January 17: NO CLASS
- Lecture 3: January 18: Stars (Virial theorem. Timescales of stellar evolution. Conditions in stellar interiors).
PDF - Lecture 4: January 22: Stars (Energy generation. The equation of conservation of energy). Basics about radiative transfer (Specific intensity).
PDF
Compulsory problems: Set 1 (return by January 29). - Lecture 5: January 24: Basics about radiative transfer (Radiation terms, specific intensity, interaction radiation – matter, parallel-ray radiative transfer equation, solution of the parallel-ray RTE)
PDF - January 25: NO CLASS
- Lecture 6: January 29: Basics about radiative transfer (Mean Intensity, Flux, and K-integral. RTE in plane-parallel atmosphere. The temperature gradient for radiative transport).
PDF - Lecture 7: January 31: The equations of stellar structure and possible ways to solve them. Boundary conditions. Convection and conditions for its occurrence. Equation of state (EOS).
PDF - February 1: NO CLASS
- Lecture 8: February 5: Solution of HW1. Lecture: the equations of stellar structure (EOS, degeneracy pressure, stellar opacity)
PDF - Lecture 9: February 7: Nuclear Energy Production (Basics on nuclear reactions, the binding energy, Quantum tunnelling, Reaction cross-section, the Gamow peak, Nuclear Reaction Rates, Electron shielding)
PDF
Compulsory problems: Set 2 (return by February 19). - Lecture 10: February 12: Nuclear reactions in stellar interiors (Energy generation, PP-chains & CNO-cycle, Helium burning, Carbon burning and beyond, iron and heavier elements, Composition changes)
PDF - Lecture 11: February 14: Solution of the Equations of Stellar Structure (The stellar structure equations and how to solve them? Simple stellar models. Polytropic models. Lane-Emden equation. Different relationships for polytropic stars. Chandrasekhar mass. Dynamical stability of stars)
PDF (Updated on 15.02.2024) - Lecture 12: February 15: Stellar evolution codes. Schematic stellar evolution. Star formation.
PDF * EZ-Web - Lecture 13: February 21: Star formation (cont). Identification of Young Stars. Pre-main sequence star evolution (the Hayashi track and the Henyey track).
PDF - Lecture 14: February 22: Main Sequence stars. Evolution of low-mass stars.
PDF - Lecture 15: February 26: Evolution of high-mass stars. The initial mass function. Solution of HW2.
PDF - February 28: Mid-term exam
- Lecture 16: February 29: The end point: stellar remnants. White dwarfs, Supernovae, Neutron stars, Black holes.
PDF - Lecture 17: March 11: What is a stellar atmosphere? Why should we care about it? What can we learn from observations? Radiative transfer (Radiative transfer equation in plane-parallel atmosphere. Limb darkening).
PDF - Lecture 18: March 13:Limb darkening (cont.), Solution to transfer equation, Eddington-Barbier relation. Grey atmosphere. Radiative equilibrium.
PDF - Lecture 19: March 18: The depth dependence of the source function. Eddington approximation. Temperature structure of the grey atmosphere. LTE (Maxwellian distribution in velocities, Boltzmann equation, Saha formula).
PDF (Updated on 21.03.2024)
Compulsory problems: Set 3 (return by March 25). - Lecture 20: March 20: Stellar Opacity (Bound-bound, bound-free and free-free absorptions).
PDF
Compulsory problems: Set 4 (return by April 3). - Lecture 21: March 25: Lyman edge and Balmer jump. Negative hydrogen ion H– as the sources of opacity. Other sources of opacity (He and Metallic absorptions, Scattering, Effect of nongreyness of the temperature structure, Balmer jump).
PDF - Lecture 22: March 27: Spectral lines (Equivalent Width, FWHM, FWZI, Radial Velocity). Spectral line formation (Einstein coefficients. Natural Line Width, Natural broadening, Doppler broadening).
PDF * Homework: slide 192 - Lecture 23: March 28: Spectral line formation (Convolution of different broadening processes, Pressure broadening, Ingis-Teller relation, Rotational and Instrumental broadening).
PDF - Lecture 24: April 4: Simple line transfer, Schuster-Schwarzschild model, Theory of line formation, Curve of Growth. Scattering in lines, Transfer Equation including lines, The Milne-Eddington model, Residual flux of the line, Absorption and scattering lines, Schuster Mechanism for Line Emission.
PDF - Lecture 25: April 8: Non-LTE (Statistical equilibrium, Two-level approximation, the line source function, LTE versus non-LTE). Spectral type sequence.
PDF
Compulsory problems: Set 5 (return by April 15). - Lecture 26: April 10: Towards the Model Photosphere (Hydrostatic equilibrium. Gas and electron pressure). Measuring temperatures and surface gravities (Direct measurement of radii. Determining teff and surface gravity, Model-independent methods, Model-dependent methods, Atmospheric models, Photometric methods, Spectroscopic methods).
PDF * Spectral classification - Lecture 27: April 15: A short introduction to the Interstellar Medium (ISM).
PDF - Lecture 28: April 17: ISM: Interstellar Absorption Lines and DIBs. 21 cm hydrogen line. Ionized regions. Strömgren Spheres.
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