SUMMARY OF PROPOSAL 42169
DR. J. GREGORY STACY
LHEA/USRA-NASA/GSFC
NH USA 03824
DURHAM
UNIVERSITY OF NEW HAMPSHIRE

  E-mail: STACY@UNH.EDU	Tel: 603-862-4708	Fax: 603-862-4685
  Medium: 4GBDAT

Subject: AGN                                                         
  Title: COORDINATED X-RAY OBSERVATIONS OF THE GAMMA-RAY BLAZARS PKS 2155-304 AND PKS 0208-512


Abstract:
 We propose to conduct coordinated ASCA x-ray observations of two southern gamma-ray
 blazars, each a prototypical member of its class: the nearby x-ray-selected BL Lac
 PKS 2155-304, newly-discovered as a gamma-ray source during our current CGRO Cycle 4
 observing program, and the bright, variable gamma-ray quasar PKS 0208-512. The
 proposed ASCA observations will be carried out in conjunction with an international
 campaign to acquire simultaneous measurements from GHz radio frequencies, including
 VLBI mapping, to GeV gamma-ray energies (TeV energies for 2155-304); these will
 provide ``snap-shots'' of the spectral energy distribution in the sources and, in
 the event of a strong flare, can serve to map out in time and space the structure of the blazar jet.

 Co-Is:
   1  HIDETOSHI KUBO      	U. TOKYO                      JAPAN     
      KUBO@ASTRO.ISAS.AC.JP	81-427-51-3911 X2612
   2  W. THOMAS VESTRAND  	UNIV. NEW HAMPSHIRE           USA       
   3  JERRY BONNELL       	LHEA/USRA-NASA/GSFC           USA       
   4  MARCO COSTA         	U. WESTERN AUSTRALIA          AUSTRALIA 
   5  IAN GLASS           	SAAO                          S AFRICA  
   6  O.C. DE JAGER       	POTCHEFSTROOM U.              S AFRICA  
   7  GEORGE NICOLSON     	HARTEBEESTHOEK RAO            S AFRICA  


Target Name           PRI RA        Dec        Time TC  Off GIS SIS_Cts  Obs
-------------------   --- --------  --------   ---- --  --- --- -------  ---
PKS 2155-304           0  329.7163  -30.2253    70   Y   Y   P  3.00000   7 

REMARKS:  PROPOSE QUASI-MONITORING OBSERVATIONS: 7 X 10 KSEC; SEE TEXT. CONSTRAINTS:
          ASCA EXPOSURE SIMULTANEOUS WITH CGRO AND/OR TEV OBSERVATIONS (TEV REQUIRES
          ``DARK'' NIGHTS).
Co-Ordinated Ob:
                Start: Apr 14, 1996 at 00 UT
                 Stop: Jun 7, 1996 at 00 UT
PKS 0208-512           0   32.6925  -51.0172    20   Y   Y   P  0.20000   2 

REMARKS:  PROPOSED OBSERVATIONS: 2 X 10 KSEC, SEPARATED BY 1-2 WEEKS. CONSTRAINT:
          ASCA EXPOSURE SIMULTANEOUS WITH CGRO.
Co-Ordinated Ob:
                Start: Jan 1, 1996 at 00 UT
                 Stop: Feb 12, 1996 at 00 UT