QUASARs and Rotating Black Holes - Landessternwarte Heidelberg ...

Radio Surveys Æ Quasar Era
• 3CR catalog (178 MHz, Bennett 1961) down to
a limiting flux of 9 Jy (1 Jy = 10 -26 W m -2 Hz -1 );
• PKS survey on the southern hemisphere (408
MHz, Ekers 1969) down to 4 Jy; later at 1410
MHz (1 Jy) and 2650 MHz (0.3 Jy);
• More sensitive 4C survey down to 1 Jy (1965);
• Ohio survey: very luminous sources (OH 471);
• 3C 48, 3C 273 first identified sources (1963).
• Later it turned out that only a minority is RL !