The Universe at Radio Wavelengths

Chapters 1-9
Powerpoint slides: 1 slide per page


Chapters

22 September 2020
Welcome to this mini course and good luck!
On the first day we talked about logistics and then started on some historical aspects and compared radio astronomy to astronomy at other wavelengths. We looked at a patchwork of radio sources and thought about what makes radio astronomy astrophysically special. We finished Chapter 1 and started on Chapter 2.

29 September 2020
In Chapter 2 we looked at the differences between brightness and flux and its spectral version, flux density. We started on Chapter 3 and covered the blackbody radiation.


6 October 2020
We continues with Chapter 3 and covered  bremsstrahlung which is also called free-free radiation in astrophysics. This kind of radiation is very common in gaseous nebula with charged particles. We looked at the range of impact parameters and interpreted a typical spectrum.


20 October 2020
We continued with cyclotron and synchrotron radiation and interpreted the spectrum. We looked at the spectra of quasars. In particular we also looked at a spectrum of a supernova and distinguished between the optically thick and optically thin part of the spectrum.

27 October 2020 
We continues with spectral line emission. We learned about the 21-cm spectral line of neutral hydrogen and the astrophysically important parameters that can be obtained through observations of the spectral line. We also learned about recombination lines. Then we started on Chapter 4. We covered the dipole antenna and the associated beam pattern, introduced dB's, introduced horn feeds and described different antenna types.