SUMMARY OF PROPOSAL 42054
DR. CRAIG R. ROBINSON
UNIVERSITIES SPACE RESEARCH ASSOCIATION
AL USA 35812
HUNTSVILLE
ES-84 USRA, NASA/MSFC

  E-mail: ROBINSON@SSL.MSFC.NASA.GOV	Tel: 205-544-8920	Fax: 205-544-5800
  Medium: 2GB8MM

Subject: X-RAY BINARIES                                              
  Title: X-RAY EMISSION FROM THE SOFT X-RAY TRANSIENT AQUILA X-1                         


Abstract:
 The soft X-ray transient Aquila X-1, due to its proximity and low absorption, has
 now been unambiguously identified several times as a source of X-rays in quiescence
 with the ROSAT PSPC and HRI. The quiescent spectrum, poorly constrained, appears
 distinctly different from the outburst spectrum. No observations have been obtained
 of Aql X-1 with the energy range and resolution necessary to determine the
 quiescent-state emission shape. We plan a single pointing. If in quiescence (highly
 likely), ASCA will observe the soft X-ray components and may reveal harder emission,
 as found in Cen X-4, perhaps from separate surface or shock-driven emission. If in
 outburst, we will use simultaneous BATSE data, which has already shown a hard X-ray component, to model the broad-band spectrum.

 Co-Is:
   1  YASUO TANAKA        	ISAS                          JAPAN     
      (No Co-I contact data)
   2  FUMIAKI NAGASE      	ISAS                          JAPAN     
   3  ALAN HARMON         	NASA/MSFC                     USA       
   4  WILLIAM PACIESAS    	UAH                           USA       
   5  SHUANG-NAN ZHANG    	USRA                          CHINA     
   6  BRAD RUBIN          	USRA                          USA       
   7  COLLEEN WILSON      	NASA/MSFC                     USA       
   8  MARCO TAVANI        	COLUMBIA                      ITALY     
   9  PHILIP, ERIC KAARET, FORD	COLUMBIA                      USA       
  10  K. ASAI             	ISAS                          JAPAN     


Target Name           PRI RA        Dec        Time TC  Off GIS SIS_Cts  Obs
-------------------   --- --------  --------   ---- --  --- --- -------  ---
AQUILA X-1             0  287.8208    0.5800    40   N   N   P  480.00000   1 

REMARKS:  ESTIMATED COUNT RATES ARE GIVEN IN TABLE I. THE SIS COUNT RATE ON TARGET
          SUMMARY PAGE IS AN EXTRAPOLATION DURING OURBURST. IT'S LIKELY THE RATE
          WILL BE LOWER (SEE PROPOSAL) REQUIRING REQUESTED TIME.