ADVANCED ASTROPHYSICS

 

The aim of the courseAdvanced Astrophysics” is to introduce a selection of  current research fields in astrophysics and prepare the participants for research in this field.

 

COURSE CONTENTS

Dynamics of Astrophysical Fluids and Plasmas (Magnetohydrodynamic approximation, Spherical Flows: Sedov Problem, Bondi Problem, stellar winds; Rotating  Flows: astrophysical disks, fluid instabilities: Rayleigh-Taylor instability, Kelvin-Helmholtz instability, rotational instability ),

Radiative Processes in Astrophysics (Radiative transfer, Bremsstrahlung, synchrotron radiation, Compton scattering)

Astrophysics of Neutron Stars (Radio Pulsars, X-Ray Pulsars, Magnetars, Star-Disk Interaction, Disk-Magnetosphere Interaction)

Astrophysics of Black Holes (Accretion onto black holes, Active Galactic Nuclei, Microquasars, X-ray binaries, Ultraluminous X-ray Sources)

 

WEEKLY SCHEDULE

1- Astrophysical fluids and plasmas: Knudsen number and the validity of the fluid approximation, conservation laws, barotropic flow, compressibility, sound velocity, hydrostatic equilibrium.

2- Fundamentals concepts of plasma physics, magnetohydrodynamic approximation, astrophysical dynamos and the induction equation, Alfvén waves.

3- Spherically symmetric flows: Sedov problem and application to supernova remnants, Bondi problem, stellar winds.

4- Fluid instabilities: Rayleigh-Taylor instability, Kelvin-Helmholtz instability, rotational instability

5- Accretion disks, Shakura-Sunyaev solution, dwarf novae and thermal instability, star-disk interaction and boundary layer, modeling the disk spectrum.

6- Self-gravitating disks, galactic dynamics, spiral density waves

7- Radiative transfer and stellar atmospheres

8- Radiative processes in astrophysics: Bremsstrahlung, synchrotron radiation, Compton scattering

9- Rotationally Powered Pulsars

10- Gravitationally Powered Pulsars

11- Young neutron star families and the magnetar hypothesis

12- Accretion disks around black holes: stellar mass black holes in our galaxy, microquasars

13- Active Galactic Nuclei: Quasars and the black hole at the center of the Galaxy.

14- Gamma Ray Bursts:History, models and their association with supernovae.

REFERENCE BOOKS

No single book covers all the course material.

1)    Astrophysical Flows, J. E. Pringle, A. King, Cambridge University Press; 1st edition (May 21, 2007)

2)   Principles of Astrophysical Fluid Dynamics, C. Clarke, B. Carswell, Cambridge University Press; 1st edition (April 30, 2007)

3)   Astrophysical Hydrodynamics: An Introduction, S. N. Shore, Publisher: Wiley-VCH; 2nd edition (September 17, 2007)

4)   Accretion Power in Astrophysics, J. Frank, A. King, D. Raine, Cambridge University Press, 3rd edition (February 11, 2002)

5)   Rotation and Accretion Powered Pulsars, P. Ghosh, World Scientific Publishing Company; 1st edition (April 17, 2007)

6)   Radiative Processes in Astrophysics, G. B. Rybicki, A. P. Lightman, Wiley-Interscience; New Ed edition (March 26, 1985)

7)   Pulsar Astronomy, A. G. Lyne, F. Graham-Smith, Cambridge University Press; 3rd edition (March 20, 2006)

8)   Compact Objects in Astrophysics: White Dwarfs, Neutron Stars And Black Holes, M. Camenzind, Springer (2007)

9)   Introduction to High-Energy Astrophysics, Rosswog, Bruggen

1)     High Energy Astrophysics, Fulvio Melia, Princeton Series in Astrophysics; 1st edition (2009)

2)   Foundations of High-Energy Astrophysics, Mario Vietri, University of Chicago Press; (2007)

3)   Theoretical Astrophysics, VOL I: Astrophysical Processes, Padmanabhan

4)   Theoretical Astrophysics, VOL II: Stars and Stellar Systems, Padmanabhan

 

FURTHER REFERENCES

These books are classic references though some of them a bit outdated

Classical Electrodynamics, Jackson

Fluid Mechanics, Landau & Lifschitz

Physics of Astrophysics, VOL I: Radiation, F. Shu

Physics of Astrophysics, VOL II: Gas Dynamics, F. Shu

Black Holes, White Dwarfs and Neutron Stars: The Physics of Compact Objects, Shapiro & Teukolski

          High Energy Astrophysics: Volume 1, Particles, Photons and their Detection, Longair

          High Energy Astrophysics: Volume 2, Stars, the Galaxy and the Interstellar Medium, Longair

 

INTERNET RESOURCES

The following links should be sufficient if you do not want to buy any books

Elements of Astrophysics, Nick Keiser

High Energy Astrophysics, Miller

Neutron Stars, Verbunt

Applications of Classical Physics, Thorne & Blandford

Lecture Notes in High Energy Astrophysics, Fransson

High Energy Astrophysics, Cumming

Astrophysical Fluid Dynamics, Pijpers

Astrophysical Fluid Dynamics, Ogilvie

Accretion Disks, Ogilvie

Astrophysical Fluid Dynamics, Bicknell

High Energy Astrophysics, Bicknell

Geophysical and Astrophysical Fluid Dynamics, Tobias

Astrophysical Plasmas, Schwartz et al.

Astrophysical Fluids, Cumming

Radiative Processes, Parsons

Radiative Processes, Blackman

Radiative Processes, UC Berkeley

Radiative Processes, Cumming

Radiative Processes, Tolstoy

Radiative Processes, Pisano

Astrophysical Dynamics, Hahn

Radiative Transfer, Rutten

Radiative Transfer & Stellar Atmospheres, Kudritzki

Astrophysial MHD, Achterberg

Advanced MHD, Goedbloed

MHD lectures, Keppens

Theoretical Astrophysics, Klessen

Theoretical Astrophysics, Bartelmann

Radiative Processes & Relativistic Flows, Markoff

Black Hole Astrophysics, Cumming

Notes by Poutanen

 

Homeworks

HW1 due 16th Feb

HW2 due 2nd March

High Energy Astrophysics: slides

Slides on rotationally powered pulsars

All about accretion disks sufficient for this course is this reference by Spruit.

The slides are here.

Slides on the Stability of Fluids

Some notes on the stability of fluids by Bestehorn

FUN LINKS

films on fluid dynamics

High Energy Astrophysics Picture of the Week

 

When a pulsar is created in a supernova explosion, it is born spinning, but slows down over millions of years. Yet if the pulsar is in a binary system, then it can pull in, or accrete, material from its companion star. This influx of material can eventually spin up the pulsar to the millisecond range, rotating hundreds of revolutions per second.

Accretion Spins Pulsar to Millisecond Range Movie (NASA courtesy)

 Accretion Spins Pulsar to Millisecond Range -- A View From Above Movie (NASA courtesy)

 

Material accumulating on the pulsar surface can sometimes ignite, causing thermonuclear flashes that emit bursts of X-ray light. These thermonuclear flames spread across the surface of the pulsar in a few seconds. The team established that "burst oscillations", a kind of flickering, during these X-ray bursts provide a direct measure of the pulsar's spin rate. Thus, these bright bursts can be used to determine pulsar spin rates throughout the galaxy. This animation is a slow-motion depiction of a thermonuclear flash or X-ray burst spreading across a rotating pulsar. The pulsar would actually be rotating hundreds of revolutions per second.

Nuclear Explosions on Pulsar Surface Help Scientists Determine Spin Rate Movie (NASA courtesy)

 

As the pulsar picks up speed through accretion, it becomes distorted from a perfect sphere due to subtle changes in the crust, depicted here by an equatorial bulge. Such slight distortion is enough to produce gravitational waves. Material flowing onto the pulsar surface from its companion star tends to quicken the spin, but loss of energy released as gravitational radiation tends to slow the spin due to the principle of conservation of energy. This competition may reach an equilibrium, setting a natural speed limit for millisecond pulsars beyond which they cannot be spun up.

 Emitted Gravitational Radiation Halts Pulsar's Spin Up Movie (NASA courtesy)

Train Yourself for the Course

Order of Magnitude Physics, Sanjoy

Order of Magnitude Physics, Parsons

Order of Magnitude Physics, Chiang

Theoretical Astrophysics, (Learn a little bit of stellar astrophysics)

Computational Astrophysics, Ricotti

Numerical Techniques in Astronomy, Brown