the discovery of quasars (the first agn found)
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The Discovery of Quasars (the first AGN found)
Maartin Schmidt – the ‘discoverer of quasars’
Cyril Hazard – the REAL DEAL
The Cambridge Catalog of Radio Sources
A few hundred of the brightest radio sources were compiled with a radio interferometer at Cambridge, England.
Unfortunately, the positions were not accurately known. These were the brightest radio sources in the sky – with the exception of the Sun and planets…
The brightest was called 3C273.
3C273 could be anywhere in this circle!
We needed a better position
Lunar Occultation to the rescue!
Must get both entry and exit from the moons limb!!
The Parkes Radio Telescope
3C273
X-ray
Radio (VLA)
Schmidt measured the spectrum:
Redshift of 0.13 indicating that the object is very far away (about 2.5 billion light years) and very bright!
Radio image of Cygnus A showing a small but very bright radio galaxy in the middle of the 320,000 ly wide lobes
A galaxy lies at the center of double radio sources
Galaxy (which is
actually quite large)
Intergalactic gas jet
Giant Gas Clouds
(surrounding the galaxy)
This object
that looks like a star must be
enormously
luminous - its
redshift indicates
it is 4 billion light years
away!!
H(permitted)
O[5007] (forbidden)
O[4959] (forbidden)
Quasars and Seyfert I’s
Seyfert II’s
Jet
Narrow line region clouds
10 – 10000 ly
Broad Line Region
(Light months)
Accretion Disk (light days)
Dusty Molecular torus
10 – 1000 ly
Black Hole
100 million solar masses
Narrow line region clouds
10 – 10000 ly
Broad Line Region
(Light months)
Accretion Disk (light days)
Dusty Molecular torus
10 – 1000 ly
Black Hole
100 million solar masses
Gas and dust inhibit the jet of particles!
Spiral versus Elliptical
galaxies
Blazar
CD QuasarLD Quasar
BLRG
NLRG
Elliptical Galaxy
BAL QSO
QSO (SEYFERT I)
FIR GALAXY (SEYFERT II)
Spiral Galaxy
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