SUMMARY OF PROPOSAL 42151
DR. ARI LAOR
CALTECH
CA USA 91125
PASADENA
130-33

  E-mail: LAOR@TAPIR.CALTECH.EDU	Tel: (818) 395-4258	Fax: (818) 796-5675
  Medium: 4GBDAT

Subject: AGN                                                         
  Title: ARE THERE INTRINSICALLY X-RAY QUIET QUASARS?                                    


Abstract:
 A recent ROSAT study of a complete & well defined sample of 23 optically selected
 QSOs indicates that in most QSOs the X-ray emission is very well correlated w/ the
 optical emission. However, three of the 23 QSOs appear to form a distinct group of
 apparently "X-ray quiet" QSOs, where the X-ray flux is 10-30 times weaker than
 expected. Do the three quasars represent a population of intrinsically X-ray quiet
 QSOs? or are these just highly absorbed, but otherwise normal QSOs? The answer has
 implications for the X-ray prod. mechanism, for the environment in the inner parts
 of QSOs, and for AGN unification models. Some hints from the ROSAT analysis suggest
 that these objects are indeed highly absorbed quasars. ASCA will allow a nearly
 clear cut test of the true nature of X-ray quiet QSOs

 Co-Is:
   1  MARTIN ELVIS        	CFA                           USA       
      ELVIS@CFA222.HARVARD.EDU	617-495-7442
   2  FABRIZIO FIORE      	CFA                           USA       
   3  MASARU MATSUOKA     	RIKEN                         JAPAN     


Target Name           PRI RA        Dec        Time TC  Off GIS SIS_Cts  Obs
-------------------   --- --------  --------   ---- --  --- --- -------  ---
PG 1411+442            0  213.4500   44.0036    40   N   Y   P  0.01575   1