SEDs
immediately show AGNs dont look like stars
Mutliwavelength
works (e.g., radio, X-ray, IR, plus optical)
E.g.,
FIRST Bright Quasar Survey
Also
possible to find via
Variability
(e.g., MACHO)
Proper
Motion (lack thereof)
Grism
Surveys (e.g., Large Bright Quasar Survey)
My NSF
proposal focuses on physical samples.