6746( 13) - 06/26/96 17:46 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6746 Version: 13 Check-in Date: 26-Jun-1996 17:43:28 1.Proposal Title: DYNAMICS OF THE CIRCUMNUCLEAR DISK OF M87 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle AGN GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: FERDINANDO MACCHETTO SPACE TELESCOPE SCIENCE INSTITUTE CoI: Philippe Crane European Southern Observatory N CoI: Alessandro Capetti Space Telescope Science Institute N CoI: William Sparks Space Telescope Science Institute N CoI: David Axon Space Telescope Science Institute N ------------------------------------------------------------------------------------ 6. Abstract We propose to obtain long slit spectra of the nucleus and circumnuclear region of M87 using the Faint Object Camera. Due to the high spatial (0.06 arcsec) and spectral resolution (3.6 Angstrom) of the FOC F/48 long slit, these spectra will allow us to trace and to model the rotation of the disk of ionized gas to a distance as close as 5 pc from the nucleus of M87. Our strategy consists of taking several parallel spectra of the extended disk with the slit perpendicular to the jet. Each spectrum, separated by 0.2" \ will provide important information on the dynamics of the disk, while also allowing us to pin-point the location of the slit with respect to the nucleus to an accuracy of better than 0.05". A final deep exposure will be thus taken with the nucleus centered in the slit aperture. These observations will provide an order of magnitude improvement in resolution and spatial coverage over the FOS spectra, and allow us to trace the line reversal through the nucleus with resolutions unattainable in any other way. If there are no surprises, these data will show a smooth Keplerian rise to 1000 km sec^-1 and a rapid transition to - 1000 km sec^-1. If this is the case, these data will be a further confirmation of the black hole hypothesis for the origin of the activity seen in M87. Of course, since these anticipated results are based on the assumptions we will test, if the data do not follow this scenario, the current model will need to be re-evaluated. ------------------------------------------------------------------------------------ 6746( 13) - 06/26/96 17:46 - [ 2] Observations Description ------------------------ The circum-nuclear disk of M87 will be observed using the Faint Object Camera long slit spectrographic facility. The slit, 0.065^ in width, will be positioned along the disk major axis and spectra will be taken in 4 locations separated by 0.2" \\ and centered on the M87 nucleus. These observations will provide a complete two-dimensional coverage of the disk. Comparing these spectra with the WFPC2 images will allow us to position the slit to within 0.05" \\ from the nucleus. The remaining 3 orbits will be used to obtain a high signal-to-noise spectrum across the nucleus and in a direction perpendicular to the jet. The F305LP filter ( G450M ) has been selected in order to isolate the first order spectrum which covers the 3600 - 5400 Angstrom \\ region and therefore includes the prominent O IILambda 3727, HBeta and O IIILambda 5007 emission lines. Archival FOS spectra and WFPC2 images of the M87 disk have been used to estimate the required exposure times. The HAlpha image has been scaled, using the measured line ratios, to simulate the images in the light of the O II and O III lines.Taking into account the instruments throughput, the expected count rate can be determined with good accuracy. These results have been checked independently using the average surface brightness measured in the archival FOS spectra, taken at 0.25^ distance from the nucleus. They agree to within 25\\%. With the adopted exposure time (one orbit in each slit location) we will able to measure the line emission O II with signal-to-noise ratios ranging from 3 to 12 (per spectral resolution element and 0.065" \\ spatial resolution element), depending on the location, over the whole disk. Binning over a few resolution elements will provide excellent signal-to-noise at still unmatchable resolutions. The counts in the O III are estimated to be 40 \\% of those obtained in O II and therefore this line will provide independent velocity estimates. With the longer exposure on the nucleus the signal -to- noise ratio is expected to be at least as high as ~ 30 per resolution element. In this spectrum stellar absorption features are also expected providing us with a direct measure of the velocity of the stellar component. Given the dispersion of the FOC in its spectrographic mode, 1.84Angstrom per pixel, and the measured rotation velocity measured with the FOS, 1000kms, the expected shift between opposite sides of the disk across the nucleus corresponds to ~ 15 pixels which will be easily measured from these spectra. These data will enable us measure the velocity field between 0.06" \\ and 1" \\ from the nucleus over ~ 100 independent locations. Real Time Justification ----------------------- An interactive acquisition is required in order to provide an initial pointing accuracy better than 0.2 arcsec. Real time analysis is then needed to pin-point the location of the nucleus. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6746( 13) - 06/26/96 17:46 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6746( 13) - 06/26/96 17:46 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 M87 GALAXY,Elliptical,Radio RA=12H 30M 49.4S +/- 0.001S, 2000 V = 1280 V = 9.6+/-0.1 Galaxy DEC=12D 23' 27" +/- 0.01" 6746( 13) - 06/26/96 17:46 - [ 5] Visit: 01 Visit Requirements: ORIENT 97D TO 112D On Hold Comments: Additional Comments: ACTUAL ALLOWABLE ORIENT RANGE IS 97D TO 112D. ORIGINAL PREFERRED ORIENT RANGE OF 220D TO 260D IS INTERFERED WITH BY SM97 MISSION, AND THE ANGLE 180D OPPOSITE IS IN SOLAR EXCLUSION. ORIENT 97D TO 112D IS NEXT MOST PREFERABLE OPTION. 102D WAS THE VALUE PICKED BASED ON SPIKE GS SUITABILITY WHICH RANGED FROM U3 = 99D TO 105D BUT THIS VALUE HAS BEEN OPENED UP TO THE WIDEST POSSIBLE RANGE IN CASE SPSS CAN FIND MORE GUIDE STARS THAN SPIKE. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 11 M87 FOC/48 ACQ 512X102 F140W PIXEL=50x25 1 5 M INT ACQ FOR 21 4 Comments: We have changed from F430W to F140W in order to avoid badly saturating the detector on recommendation of the FOC Instrument Scientist. There may still be some non-linearity but should not be too bad. ------------------------------------------------------------------------------------------------------------------------------------ 21 M87 FOC/48 SPEC 512X102 G450M PIXEL=25x25 1 2000 S EXPAND POS TARG -0.2,0 RT 4-SLIT ANALYSIS FOR 51 Comments: G450M is the functional equivalent of F305LP with GRATING. REAL TIME ANALYSIS OF THIS EXPOSURE IS REQUIRED BEFORE UPDATING POINTING FOR LINE 51. ------------------------------------------------------------------------------------------------------------------------------------ 22 INTFLAT FOC/48 RESEAU 512X102 CLEAR PIXEL=25X25,LED=GREEN-2, 1 10 M 4 LED-STEP=24 ------------------------------------------------------------------------------------------------------------------------------------ 23 DARK FOC/48 IMAGE 512X102 CLEAR PIXEL=25x25 1 10 M 4 ------------------------------------------------------------------------------------------------------------------------------------ 31 M87 FOC/48 SPEC 512X102 G450M PIXEL=25x25 1 2000 S EXPAND POS TARG 0,0 RT 4-SLIT ANALYSIS FOR 51 Comments: G450M is the functional equivalent of F305LP with GRATING. REAL TIME ANALYSIS OF THIS EXPOSURE IS REQUIRED BEFORE UPDATING POINTING FOR LINE 51. ------------------------------------------------------------------------------------------------------------------------------------ 32 INTFLAT FOC/48 RESEAU 512X102 CLEAR PIXEL=25X25,LED=GREEN-2, 1 10 M 4 LED-STEP=24 ------------------------------------------------------------------------------------------------------------------------------------ 33 DARK FOC/48 IMAGE 512X102 CLEAR PIXEL=25X25 1 10 M 4 ------------------------------------------------------------------------------------------------------------------------------------ 41 M87 FOC/48 SPEC 512X102 G450M PIXEL=25x25 1 2300 S EXPAND POS TARG +0.2,0 RT 4-SLIT ANALYSIS FOR 51 Comments: G450M is the functional equivalent of F305LP with GRATING. REAL TIME ANALYSIS OF THIS EXPOSURE IS REQUIRED BEFORE UPDATING POINTING FOR LINE 51. ------------------------------------------------------------------------------------------------------------------------------------ 6746( 13) - 06/26/96 17:46 - [ 6] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 42 INTFLAT FOC/48 RESEAU 512X102 CLEAR PIXEL=25X25,LED=GREEN-2, 1 10 M 4 LED-STEP=24 ------------------------------------------------------------------------------------------------------------------------------------ 43 DARK FOC/48 IMAGE 512X102 CLEAR PIXEL=25X25 1 10 M 4 ------------------------------------------------------------------------------------------------------------------------------------ 51 M87 FOC/48 SPEC 512X102 G450M PIXEL=25x25 1 2600 S REQ UPLINK 4-SLIT Comments: G450M is the functional equivalent of F305LP with GRATING. REAL TIME ANALYSIS OF POINTINGS FROM LINES 21, 31, AND 41 IS REQUIRED BEFORE UPLINKING UPDATED TARGET POSITION FOR THIS EXPOSURE LINE. LINES 61 AND 71 ARE ALSO TO BE DONE AT THE SAME FINAL UPLINKED POSITION USED FOR THIS LINE ( LINE 51 ). ------------------------------------------------------------------------------------------------------------------------------------ 52 M87 WFPC2 IMAGE PC1-FIX F555W 2 400 S PARALLEL WITH 51 ------------------------------------------------------------------------------------------------------------------------------------ 53 M87 WFPC2 IMAGE PC1-FIX F814W 2 400 S PARALLEL WITH 51 ------------------------------------------------------------------------------------------------------------------------------------ 54 INTFLAT FOC/48 RESEAU 512X102 CLEAR PIXEL=25X25,LED=GREEN-2, 1 10 M 4 LED-STEP=24 ------------------------------------------------------------------------------------------------------------------------------------ 55 DARK FOC/48 IMAGE 512X102 CLEAR PIXEL=25X25 1 10 M 4 ------------------------------------------------------------------------------------------------------------------------------------ 61 M87 FOC/48 SPEC 512X102 G450M PIXEL=25x25 1 2600 S 4-SLIT Comments: G450M is the functional equivalent of F305LP with GRATING. DO AT SAME POSITION AS THE UPLINKED FINAL POSITION FOR 51. ------------------------------------------------------------------------------------------------------------------------------------ 62 M87 WFPC2 IMAGE PC1-FIX F555W 2 400 S PARALLEL WITH 61 ------------------------------------------------------------------------------------------------------------------------------------ 63 M87 WFPC2 IMAGE PC1-FIX F814W 2 400 S PARALLEL WITH 61 ------------------------------------------------------------------------------------------------------------------------------------ 64 INTFLAT FOC/48 RESEAU 512X102 CLEAR PIXEL=25X25,LED=GREEN-2, 1 10 M 4 LED-STEP=24 ------------------------------------------------------------------------------------------------------------------------------------ 65 DARK FOC/48 IMAGE 512X102 CLEAR PIXEL=25X25 1 10 M 4 ------------------------------------------------------------------------------------------------------------------------------------ 71 M87 FOC/48 SPEC 512X102 G450M PIXEL=25x25 1 2600 S 4-SLIT Comments: G450M is the functional equivalent of F305LP with GRATING. DO AT SAME POSITION AS THE UPLINKED FINAL POSITION FOR 51. ------------------------------------------------------------------------------------------------------------------------------------ 72 M87 WFPC2 IMAGE PC1-FIX F555W 2 400 S PARALLEL WITH 71 ------------------------------------------------------------------------------------------------------------------------------------ 73 M87 WFPC2 IMAGE PC1-FIX F814W 2 400 S PARALLEL WITH 71 ------------------------------------------------------------------------------------------------------------------------------------ 6746( 13) - 06/26/96 17:46 - [ 7] Summary Form for Proposal 6746 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOC/48 WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ SPEC RESEAU IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters PIXEL=50x25 PIXEL=25x25 LED-STEP=24 LED=GREEN-2 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category AGN ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 97D TO 112D INT ACQ FOR 21 EXPAND POS TARG -0.2,0 RT ANALYSIS FOR 51 EXPAND POS TARG 0,0 RT ANALYSIS FOR 51 EXPAND POS TARG +0.2,0 RT ANALYSIS FOR 51 REQ UPLINK PARALLEL WITH 51 PARALLEL WITH 61 PARALLEL WITH 71 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F140W G450M CLEAR F555W F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names M87 INTFLAT DARK ------------------------------------------------------------------------------------------------------------------------------------