8140( 3) - 02/19/99 10:33 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8140 Version: 3 Check-in Date: 19-Feb-1999 10:32:58 1.Proposal Title: Far-UV STIS Imaging of the M87 Jet ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: John Biretta Space Telescope Science Institute CoI: Dr. Eric Perlman Space Telescope Science Institute N CoI: Dr. William Sparks Space Telescope Science Institute N CoI: Dr. Duccio Macchetto Space Telescope Science Institute N ------------------------------------------------------------------------------------ 5. Abstract We propose far-UV STIS imaging observations as part of our ongoing investigation of the M87 jet. The proposed observations will give the high-frequency spectral shape and cut-off frequency throughout the jet; these are expected to respond sensitively to the acceleration and energy loss mechanisms at work in extragalactic jets. Our cycle 4-7 monitoring program reveals striking evolution in the jet structure. Many components vary significantly with time; new ones emerge, while others fade from view over just a few years. Numerous superluminal components are seen with speeds between 2c and 6c. STIS observations will give us the unique opportunity to study the evolution of the high-frequency spectrum as these new features are born and fade away. Current models place the M87 synchrotron cut-off frequency near 1500Angstrom, making far-UV observations essential. ------------------------------------------------------------------------------------ 8140( 3) - 02/19/99 10:33 - [ 2] Observations Description ------------------------ We will obtain STIS FUV/F25SRF2 and NUV/F25QTZ images of the jet using 3 orbits. These filters were chosen to avoid the defocus of the ``clear'' filter, with attention to maximizing the FUV throughput. Our exposure estimates are based on the superluminal knots in region HST-1 which have estimated fluxes 2e- 18 erg cm^-2 s^-1 AA^-1 at 3000Angstrom, assuming a nu^-1 spectrum found in nearby knots. A 3000s FUV exposure yields SNR=15 using ``shadow time, " and a 1500s NUV exposure gives SNR=19. Faint inter-knot regions will have FUV SNR 10 for 0.25" apertures. The sub-exposures will be dithered to minimize detector artifacts. There should be no bright object issues for the M87 nucleus. Using our FOC F140W and F342W images, and WFPC2 F300W data, we have derived a spectrum 2.9e-16 * (lambda/3000Angstrom)^0.2 erg cm^-2 s^-1 AA^-1 for the integrated light of the inner 0.15". This accurately reproduces the FOC and WFPC2 countrates in SYNPHOT. When used with both STIS ETC and SYNPHOT, and assuming a point source, we obtain peak count rates of 1.7 and 12 c/s/pix for FUV/F25SRF2 and NUV/F25QTZ, respectively; both are well below the 100 c/s/pix limit for variable sources. We also request a fourth orbit for WFPC2 imaging in F300W, F450, F606W, and F814W. These observations will serve to anchor-down the long-wavelength end of the spectrum for purposes of spectral fitting. Since the jet features vary rapidly, contemporary WFPC2 data are needed. Real Time Justification ----------------------- We request that these observations be made in April - May, 1999, even though this is before the official start of Cycle 8. As we stated in our phase 1 proposal, we need these observations to be taken close in time to our June - Aug 1999 FOC observations in proposal 7274, since we must transition our monitoring program from the FOC (soon to be de-orbited) to STIS. We also need "shadow time" to get enough SNR in the far-UV. The only time period which satisfies these two constraints is April - May, 1999. We have tried all possible ORIENTS, SCHED 100%, etc., but no other time period seems possible. It appears to be limited mostly by the SHADOW requirement. We request ``shadow time'' since it increases the FUV SNR by a factor of three for faint jet features (from STIS ETC). We ask that the proposed STIS and WFPC2 observations be taken as close as possible in time to our granted FOC F342W monitoring observation in mid-1999. This will allow the STIS NUV exposure to be used to ``bootstrap" future monitoring to the existing FOC data record, after the FOC is de-orbited in 2000. The monitoring observations referred to in the previous discussion have already been approved in Cycles 7-8. In addition, we have already-approved VLA, VLBA and MERLIN observations in the radio, and on-going ROSAT observations in the X-ray. Our future plans include proposing for AXAF monitoring of M87. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8140( 3) - 02/19/99 10:33 - [ 3] Data Distribution Paper Products: NO Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8140( 3) - 02/19/99 10:33 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 M87-NUC GALAXY, RADIO GALAXY, RA = 12H 30M 49.386S +/- 0.01S, 2000 Z = V = 16.7 NUCLEUS, JET DEC = 12D 23' 27.812" +/- 0.01", 0.0043 PLATE-ID=00IY 8140( 3) - 02/19/99 10:33 - [ 5] Visit: 01 Visit Priority: Visit Requirements: PCS MODE Fine ORIENTation 90D TO 130D BETWEEN 1-APR-1999 AND 30-SEP-1999 SCHED 100% 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 ------------------------------------------------------------------------------------------------------------------------------------ 101 M87-NUC STIS/F ACCUM F25SRF2 MIRROR 1 850 S POS TARG -7.000,+7.000; UV-MAM SHADOW A Comments: dither on 10.25 pixel centers = 0.25215 arcsec roughly following offical box dither ------------------------------------------------------------------------------------------------------------------------------------ 102 M87-NUC STIS/F ACCUM F25SRF2 MIRROR 1 850 S POS TARG -6.496,+6.748; UV-MAM SHADOW; EXPAND; END ORBIT A ------------------------------------------------------------------------------------------------------------------------------------ 103 M87-NUC STIS/F ACCUM F25SRF2 MIRROR 1 910 S POS TARG -6.244,+6.244; UV-MAM SHADOW; EXPAND A ------------------------------------------------------------------------------------------------------------------------------------ 104 M87-NUC STIS/F ACCUM F25SRF2 MIRROR 1 910 S POS TARG -6.748,+6.496; UV-MAM SHADOW; EXPAND; END ORBIT A ------------------------------------------------------------------------------------------------------------------------------------ 201 M87-NUC STIS/N ACCUM F25QTZ MIRROR 1 600 S POS TARG -7.00,+7.00 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 202 M87-NUC STIS/N ACCUM F25QTZ MIRROR 1 600 S POS TARG -6.496,+6.748 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 203 M87-NUC STIS/N ACCUM F25QTZ MIRROR 1 600 S POS TARG -6.244,+6.244 UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 204 M87-NUC STIS/N ACCUM F25QTZ MIRROR 1 600 S POS TARG -6.748,+6.496; UV-MAM EXPAND; END ORBIT A ------------------------------------------------------------------------------------------------------------------------------------ 8140( 3) - 02/19/99 10:33 - [ 6] Visit: 02 Visit Priority: Visit Requirements: PCS MODE Fine ORIENTation 100D TO 120D BETWEEN 1-APR-1999 AND 30-SEP-1999 GROUP 1-2 WITHIN 30D On Hold Comments: Additional Comments: WFPC2 M87-NUC; THIS VISIT REQUIRES 2 ORBITS Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 500 M87-NUC WFPC2 IMAGE PC1-FIX F450W CR-SPLIT=0.5,CR-TOLERANCE=0.1 1 320 S POS TARG +7.0,+7.0 ------------------------------------------------------------------------------------------------------------------------------------ 510 M87-NUC WFPC2 IMAGE PC1-FIX F814W 3 160 S SAME POS AS 500 ------------------------------------------------------------------------------------------------------------------------------------ 520 M87-NUC WFPC2 IMAGE PC1-FIX F606W CR-SPLIT=0.5,CR-TOLERANCE=0.1 1 320 S SAME POS AS 500 ------------------------------------------------------------------------------------------------------------------------------------ 530 M87-NUC WFPC2 IMAGE PC1-FIX F300W CR-SPLIT=0.5,CR-TOLERANCE=0.1 1 400 S SAME POS AS 500; MIN DUR; MAX DUR 200% ------------------------------------------------------------------------------------------------------------------------------------ 8140( 3) - 02/19/99 10:33 - [ 7] Summary Form for Proposal 8140 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F25SRF2 F25QTZ PC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/FUV-MAMA STIS/NUV-MAMA WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=0.5 CR-TOLERANCE=0.1 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE Fine ORIENTation 90D TO 130D BETWEEN 1-APR-1999 AND 30-SEP-1999 SCHED 100% POS TARG -7.000,+7.000; SHADOW POS TARG -6.496,+6.748; SHADOW; EXPAND; END ORBIT POS TARG -6.244,+6.244; SHADOW; EXPAND POS TARG -6.748,+6.496; SHADOW; EXPAND; END ORBIT POS TARG -7.00,+7.00 POS TARG -6.496,+6.748 POS TARG -6.244,+6.244 POS TARG -6.748,+6.496; EXPAND; END ORBIT PCS MODE Fine ORIENTation 100D TO 120D BETWEEN 1-APR-1999 AND 30-SEP-1999 GROUP 1-2 WITHIN 30D POS TARG +7.0,+7.0 SAME POS AS 500 SAME POS AS 500; MIN DUR; MAX DUR 200% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR F450W F814W F606W F300W ------------------------------------------------------------------------------------------------------------------------------------ Target Names M87-NUC ------------------------------------------------------------------------------------------------------------------------------------