Hidden Quasars in Ultraluminous Infrared Galaxies
  Many ultraluminous infrared galaxies (ULIRGs) are powered by quasars hidden in the center, but many are also powered by starbursts. A simply diagnostic diagram is proposed that can identify obscured quasars in ULIRGs by their high-ionization emission lines ([O III] 5007/Hbeta >~ 5), and ``warm'' IR color (f_{25}/f_{60} >~ 0.25). 
H. D. Tran, M. S. Brotherton, S. A. Stanford, & W. van Breugel   (IGPP/LLNL)