6290( 4) - 09/14/95 14:56 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6290 Version: 4 Check-in Date: ********** 1.Proposal Title: THE ULTRAVIOLET SPECTRUM OF THE CRAB PULSAR ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle HOT STARS,NEUTRON STA GTO/HSP 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: ROBERT BLESS UNIVERSITY OF WISCONSIN CoI: EDWARD L. ROBINSON UNIVERSITY OF TEXAS Y ------------------------------------------------------------------------------------ 6. Abstract The time-averaged ultraviolet spectrum of the Crab pulsar will be measured with the FOS using the G160L grating in the ACCUM mode. The grating covers from 1150 A to 2510 A at a dispersion of 6.87 A/diode. The 0.3 arcsec diameter aperture will be used in order to exclude as much as possible of the surrounding nebula. The observed spectrum will be corrected for interstellar extinction; It will be necessary to investigate whether a standard interstellar extinction curve is appropriate for the pulsar. The expected results are: 1) A measurement of the ultraviolet spectrum from the Crab pulsar. 2) A measurement of the interstellar extinction to the Crab pulsar, and a measurement of -- or a limit on -- any difference between the extinction of the pulsar and the extinction of the surrounding nebula. This will allow some estimates of the internal extinction in the nebula. 3) A measurement of the de- extincted ultraviolet spectrum from the pulsar and thus a measurement of the slope of the spectrum. ------------------------------------------------------------------------------------ 6290( 4) - 09/14/95 14:56 - [ 2] Observations Description ------------------------ We will measure the time-averaged ultraviolet spectrum of the Crab pulsar with the Faint Object Spectrograph in the ACCUM mode using the BLUE detector and the G160L grating. This grating and detector combination covers from 1150 A to 2510 A with a dispersion of 6.87 A/diode. The 0.3 arcsec aperture will be used in order to exclude as much of the surrounding nebula as possible. The time averaged fluxes from the Crab pulsar should be F(2000.0) = 3.7 +/- 1.0 E-16 and F(1300.0) = 1.0 +/- 1.0 E-16 erg/cm^2/sec/A. Using Figure 1.2.3 in Version 5.0 of the FOS Instrument Handbook, we estimate that the pulsar will give a signal of 0.036 counts/sec/diode at 2000 A and 0.004 counts/sec/diode at 1300 A. We will integrate the Crab spectrum for 15,000 seconds and expect to detect ~550 counts/diode at 2000 A and 60 counts/diode at 1300 A. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- The Crab pulsar is in the Crab nebula. ------------------------------------------------------------------------------------ Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6290( 4) - 09/14/95 14:56 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PSR0531+21 STAR,PULSAR, RA=5H 34M 31.973S +/- 0.005S, J2000 V = 16.75 +/- 0.2 DEC= 22D 0' 52.06" +/- 0.06" F(2000.0) = 3.7 +/- 1.0 E-16 F(1300.0) = 1.0 +/- 1.0 E-16 6290( 4) - 09/14/95 14:56 - [ 4] Visit: 01 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 PSR0531+21 FOS/BL ACQ/PEA 4.3 MIRROR SEARCH-SIZE- 1 2.5S ONBOARD ACQ FOR 20 K Y=3, SEARCH- SIZE-X=1, SCAN- STEP-Y=1.204 Comments: PULSAR IS IN THE CRAB NEBULA. BACKGROUND FLUCTUATIONS EXPECTED. ------------------------------------------------------------------------------------------------------------------------------------ 20 PSR0531+21 FOS/BL ACQ/PEA 1.0 MIRROR SEARCH-SIZE- 1 2.5S ONBOARD ACQ FOR 30 K Y=2, SEARCH- SIZE-X=6, SCAN- STEP-Y=0.602, SCAN-STEP- Comments: X=0.602 ------------------------------------------------------------------------------------------------------------------------------------ 30 PSR0531+21 FOS/BL ACQ/PEA 0.5- MIRROR SEARCH-SIZE-Y=3 1 2.5S ONBOARD ACQ FOR 40 K PAIR SEARCH-SIZE-X=3 SCAN-STEP- Y=0.29 SCAN- STEP-X=0.29 ------------------------------------------------------------------------------------------------------------------------------------ 40 PSR0531+21 FOS/BL ACQ/PEA 0.25- MIRROR SEARCH-SIZE- 1 25S ONBOARD ACQ FOR 50 K PAIR Y=5, SEARCH- SIZE-X=5, SCAN- STEP-Y=0.052 SCAN-STEP- Comments: CRITICAL ACQ/PEAK STAGE. EXPOSURE TO PRODUCE X=0.052 10000 COUNTS ------------------------------------------------------------------------------------------------------------------------------------ 50 PSR0531+21 FOS/BL ACCUM 0.25- G160L 1500.0 STEP- 1 15000S PAIR-A PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 6290( 4) - 09/14/95 14:56 - [ 5] Summary Form for Proposal 6290 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SEARCH-SIZE-Y=3 SEARCH-SIZE-X=1 SCAN-STEP-Y=1.204 SCAN-STEP-X=0.602 SEARCH-SIZE-Y=3 SEARCH-SIZE-X=3 SCAN-STEP-Y=0.29 SCAN-STEP-X=0.29 SCAN-STEP-Y=0.052 SCAN-STEP-X=0.052 STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GTO/HSP ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS,NEUTRON STARS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 20 ONBOARD ACQ FOR 30 ONBOARD ACQ FOR 40 ONBOARD ACQ FOR 50 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G160L ------------------------------------------------------------------------------------------------------------------------------------ Target Names PSR0531+21 ------------------------------------------------------------------------------------------------------------------------------------