69059 - Radioastronomy

Academic Year 2018/2019

  • Teaching Mode: Traditional lectures
  • Campus: Bologna
  • Corso: Second cycle degree programme (LM) in Astrophysics and cosmology (cod. 8018)

Learning outcomes

At the end of the course, the student will gain a deeper knowledge of the concepts regarding the synchrotron radiation and its relation with other processes of the production of radiation in astrophisics. The student will have advanced knowledge on new topics regarding radioastronomy, in the general scenario of modern astrophysical research. The student will be able to understand and present in a critical manner research papers on arguments discussed during the course.    

Course contents

a) Emission mechanisms and some aspects of synchrotron theory (e.g. polarization, ageing, magnetic field etc.) = very important for those without a bachelor in Astronomy =

b) Observational techinques in radio astronomy. Radiotelescope:hostorical, present and future instruments.

c) Magnetic field: synchrotron emission, polarization, Faraday rotation, Zeeman effect, magnetic field in the Galaxy and in the galactic centre, magnetic field in spiral galaxies.

d) Interstellar medium: brief description of the composition, HI, masers, molecules. Molecules and star formation in galaxies. Giant Molecular Clouds, Bok's globules and Herbig-Haro objects. Various classes of protostars

e) Radio Stars: radio surveys and the radio H-R diagram, radio emission from stellar atmospheres, radio flares from cool stars, quiescent emission from coronae of cool stars, radio flares and coronal heating, stellar magnetic fields, radio coronal structures, radio emission from chromospheres and winds, star formation and solar-stellar connection, radio emission from brown dwarfs, stellar astrometry. Magnetic stars and classification/examples.

f) Supernovae: optical characteristics, supernovae remnants ( radio properties, dynamical evolution, brightness-diameter relation, energy considerations). Characteristic times of the various phases of the expanding envelope.

g) Pulsars: properties (distribution, period, prifile, radio spectrum, brightness temperature, age, distance, luminosity function). Neutron stars: mass, radius, moment of inertia, structure, magnetosphere, energetics, gravitational physics in the strong-field regime, keplerian and post-keplerian parameters, the double pulsars.  

h) Radio emission from stellar end-products: jets in cataclismic variables, X binaries, microquasars (general properties, superluminal motions, multi-frequency data in the context of the current model).

i) A multi-wavelength view of the Galactic Center: HI, radio (spectrum, variability, polarization of the various components), IR, molecules and maser, X emission. Special properties related to unusual star formation.

l) Radio emission of normal galaxies: HII regions, supernovae, different components, the Milky Way (outline of the optical and radio emission of the different components (disk, halo), the spectral characteristics, the thermal and non-thermal components; outline of the X and gamma emission; the magnetic field).

m) Radio emission in spiral galaxies: spectrum, polarization of the components, comparison with the X-ray emission, luminosity function, radio-IR/radio-CO correlation and discussion of a simple model, estimates of stellar formation, HI, rotation curves. Oort's constants and the kinematics of the Milky Way. Dark matter, Tully-Fisher relation, the environment.

n) Radio faint population: observational technique, counts, radio/FIR relation, composition, optical and radio properties.

o) Radio active sources. Classification and self-similar evolutionary model

p) Diffuse emission in clusters of galaxies, non-thermal plasma and its interaction with the thermal plasma.

 

Readings/Bibliography

a) Verschuur G.L., Kellermann K.I., "Galactic and Extragalactic Radioastronomy", Springer-Verlag

b) Longair M.S., "High Energy Astrophysics", Cambridge University Press - 

c) Manchester R.N., Taylor J.H., "Pulsars", Freeman and Co., San Francisco -

d) Rohlfs K., Wilson T.L., "Tools of Radio Astronomy" Springer

e) Fanti C. e Fanti R. "Una finestra sull'Universo Invisibile" (dispense)

f) papers published in scientific journals

Teaching methods

Lectures and a few exercises (just to keep in mind the order of magnitude of some quantities). Often the student may be asked to argue on some problems. 

The slides used during the lectures are available well prior the lectures take place.

Assessment methods

Oral examination. The candidate will present a paper she/he at her/his own choice. Subsequently, other two topics will be discussed. They will be chosen by the examiner.

Links to further information

http://www.ira.inaf.it/~ddallaca/Radioastronomy.html

Office hours

See the website of Daniele Dallacasa