1. (history of radio polarization)
Cosmic magnetism
(history of radio polarization)
Richard Wielebinski MPI für Radioastronomie, Bonn IAU Hawaii,

2. planetary motion is due to gravity
Johannes Kepler suggests magnetic fields responsible for planetary motion ca. 1609
William Gilbert
made experiments
with magnets
ca. 1600
Isaac Newton
shows that
planetary motion is due to gravity
ca.1700 2

3. J. C. Maxwell , 1865 Cambridge Electromagnetic theory
Heinrich Hertz
1885, Karlsruhe
1886, Bonn
Dipoles must
be aligned
Polarization!

4. P. Zeeman, 1896 remote sensing of magnetic fields
Polarization !
G.E.Hale - Zeeman Effect in Sunspots, 1908
H.W. Babcock - Zeeman Effect in stars, 1947 4

5. a pioneer of polarization
Solar researchers were first to discover cosmic radio polarization Martyn: Polarization of Solar radio waves Appelton & Hey; Ryle & Vonberg: Circular polarization of Solar emission K.O.Kiepenheuer: Radio waves originate in magnetic fields
Joe Pawsey
a pioneer of polarization

6. Methods of measurement of cosmic magnetic fields
Zeeman effect (optical and radio)
Optical polarization (+ Davis-Greenstein Effect)
Radio continuum
total intensity
linear polarization
Faraday rotation
radio continuum
extragactic sources
pulsars 6

7. Radio polarimetry ca. 1953 Naval Research Laboratory
Washington D.C.
50 foot dish
Pioneers of polarization
1957
Mayer McCullough Sloanaker,
Detection of polarization
In the Crab Nebula at 3.15 cm
Simple rotating feed

8. Lebedev Physical institute
Radio polarimetry in USSR confirmation of the polarization of Crab Nebula at 21 cm wavelength
31m dish of the
Lebedev Physical institute
Kuzmin Udalt’sov, 1957
Ferrite polarization
tranducer

9. Polarization of Jupiter
Radhakrishnan & Roberts, 1960
Jupiter has 30% linear polarization

10. Dwingeloo Westerhout et al. 1962 Detection of polarization
in the Milky Way
Galactic Faraday Rotation
Muller et al. 1963
Correlation polarimeter

11. Cambridge Wielebinski et al. 1962, Detection of polarization
In the Milky Way
Wielebinski & Shakeshaft, 1962
Ionospheric Faraday Rotation
Switching polarimeter, rotating feed and receiver

12. Magnetic fields in the Milky Way ←WMAP 32 GHZ Galactic Centre 32 GHz
W.Reich
Vertical field
21cm © MPIfR→

13. 100 m dish
Effelsberg
11cm polarization
survey

14. M51
NGC7479
Magnetic fields
in galaxies
©MPIfR
NGC4631

15. Parkes Bracewell et al. 1962 Detection of polarization In Centaurus A
Cooper & Price, 1962
Faraday Rotation in
Cenaturus A
Mayer et al. 1962
In Cygnus A

16. The catalogues of RM of sources made in 1960s
allowed the compilations of RMs of the Galaxy
1980
Simrad-Normandin & Kronberg

17. The early source surveys avoided the Galactic plane
Van Eck et al.
J-A Brown et al.
Haverkorn et al.
The early source surveys avoided the Galactic plane
At first pulsars closed the gap. Now EGRS data came.

18. A new method of displaying RM distribution

19. Single dish observations <— of Cas A
© NRAO Tuffs et al. VLA
Mayer et al. 1968

20. Westerbork Magnetic fields in radio galaxies 1970s Miley, 1973
Hœgbom 1974

21. VLA Studies of galaxies radio galaxies and jets in AGNs
Magnetic phenomena
1980s

22. of polarization mapping
1968 1,2 cm
140 ft dish
Mayer et al.
Development
of polarization mapping
Cygnus A
1974 Hargrave & Ryle 2cm
6cm©NRAO

23. Centaurus A Parkes 2013 Shimwell Fein et al. ©.ATNF
1962 Cooper & Price
1990 Junkes

24. Intergalactic magnetic fields in Coma cluster Thierbach et al. 2003
Coma halo
Kim et al →
Rotation Measure
of quasars

25. Pulsar polarization 0° 90° Lyne & Smith, 1968 ↑ Pulsars have the
most unusual
polarization
Karastergiou et al. →

26. Radio Zeeman Effect Bolton & Wild, 1957 suggest the use of the HI line
For measurement of magnetic fields
Verschuur, 1968 makes first detection
Later other molecular lines are used.

27. Magnetic fields have been
grossly neglected
Waiting for SKA
THANK YOU !!