9503( 8) - 10/30/02 15:14 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 9503 Version: 8 Check-in Date: 30-Oct-2002 15:14:00 1.Proposal Title: Milli-arcsec Registration of Nuclear Optical and Radio Structures in the Seyferts NGC 1068 and NGC 4151 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 11 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Neil Nagar Osservatorio Astrofisico di Arcetri CoI: Dr. Patrick Shopbell California Institute of Technology N CoI: Dr. Roberto Maiolino Osservatorio Astrofisico di Arcetri N CoI: Dr. Alessandro Marconi Osservatorio Astrofisico di Arcetri N ------------------------------------------------------------------------------------ 5. Abstract We propose to obtain accurate (as good as ~15 milli-arcsec) absolute positions for the complex optical continuum and emission-line structures in the nuclei of NGC 1068 and NGC 4151, by bootstrapping positions from Hipparcos catalog stars in the same ACS/WFC field-of-view. This will also allow us to obtain accurate absolute positions for the central engine - as traced by HST imaging polarimetry in NGC 1068, and by kinematics of emission-line clouds in NGC 4151. The absolute positions of the optical features will be compared with those of the complex milli-arcsec-scale nuclear radio structures in order to: (a) identify the radio component corresponding to the central engine or determine if it is absorbed; (b) use the central engine position, in conjunction with already determined nuclear radio structure and free- free- and H I- absorption to the nuclear radio sources, to construct a more accurate model for the central engine and obscuring torus in AGN; (c) look for detailed correlations (or lack thereof) between the radio jets and the emission-line gas at the milli- arcsec level. An absolute position determination makes all prior and future HST observations of these galaxies more useful. Prompt observations are required as the position uncertainties of the Hipparcos stars are increasing with time. In case of technical problems with ACS, the goals of the project can be achieved with WFPC2 imaging. ------------------------------------------------------------------------------------ 9503( 8) - 10/30/02 15:14 - [ 2] Observations Description ------------------------ The two target galaxies and the calibration field (47Tuc) will be observed in consecutive orbits so as to obtain consistent and accurate solutions to the geometric distortion and PSF. Basic geometric distortion correction will be done using the results of the ACS team and of GO9443 (P.I. King). The geometric distortion in ACS is best characterized through F475W so this should be the natural choice for the project. However, to avoid saturation on the bright stars in our fields we will use F550M instead. Our observations of 47Tuc will be used to determine the geometric distortion through F550M and to check for time variation in the distortion calculated by the earlier projects. Two FGS fine-lock guiding will be used to minimize telescope drift. To minimize overheads in ACS buffer dumps only a single WFC chip will be read out whenever possible. For NGC 1068 a single pointing is sufficient as the nearest Hipparcos star is 1.5 arcmin E and 0.6 arcmin S of the nucleus. An additional offset pointing - covering additional stars with accurate positions - will also be taken to better constrain the orientation of the telescope. For NGC 4151 three overlapping pointings are required given the distance of the Hipparcos star. Dithering will be used whenever possible; at each dither position which includes a bright star we use a short (~0.8sec) exposure to fix the position of the bright star and a longer (~180sec) exposure to detect fainter stars and continuum features. The longer exposure times will cause blooming along columns for the brighter stars but the absence of bright object limits for ACS mean that there is no danger of any damage to the instrument. The observing sequence will therefore be the following: 1) For NGC1068: obtain 0.8sec and 180sec exposures of the main field (NGC1068-NUC) containing both the galaxy nucleus and the Hipparcos star, in multiple dithered positions (only one WFC chip requires to be read out). Then offset the telescope to a field (NGC1068-OFF) covering both the Hipparcos star and two additional stars with accurate positions and obtain a quick exposure. 2) For NGC 4151: obtain a sequence of short, long, short exposures on the nuclear field (NGC4151-POS1); offset to an overlapping field (NGC4151-POS2) and take a single exposure; offset to the field containing the nearby Hipparcos star (NGC4151-POS3) and obtain a short exposure (through F502N to avoid saturation on the V=8.2mag star) followed by a 2sec exposure through F550M in order to also detect the fainter stars. There are sufficient stars in the overlapping regions of the fields to transfer positions across the three fields. 3) For the calibration field (47 Tuc), obtain 90 sec dithered exposures through F550M, followed by exposures in each of F475W, F502N and F658N. We will thus use one orbit for each of NGC 1068, NGC 4151, and 47Tuc. Roll angles have be chosen so that the diffraction spikes and blooming from the bright stars will not fall on the fainter stars and continuum features. Real Time Justification ----------------------- All three targets require to be observed consecutively as justified below. Observations of the crowded stellar field (47 Tuc) will be used to: (a) check for variability in the previously determined (by the ACS instrument team) geometric distortions for WFC through F475W, and to remeasure the inter-chip gap. (b) check the geometric distortion through the F550M filter. (c) determine an accurate PSF at the time of the target observations, from the multitude of stars in the 47Tuc field. Calibration Justification ------------------------- 9503( 8) - 10/30/02 15:14 - [ 3] Additional Comments ------------------- ------------------------------------------------------------------------------------ 9503( 8) - 10/30/02 15:14 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC1068-NUC GALAXY, SEYFERT, SPIRAL RA=02H 42M 42.83S +/- 1.0", J2000 V = 11.02+/-0.05 DEC=-00D 1' 7.53" +/- 1.0", PLATE-ID=0085 Coordinate Source: GSC_SURVEY_PLATE Comments: Coordinates generated within VTT (aperture=WFC2-FIX). Field includes NGC1068 nucleus and HIP12668 (V_mag = 10.81). WF2 readout required, WF1 readout optional. 2 NGC1068-OFF GALAXY, SEYFERT, SPIRAL RA=02H 42M 50.45S +/- 1.0", J2000 V = 11.02+/-0.05 DEC=-00D 1' 40.76" +/- 1.0", PLATE-ID=0085 Coordinate Source: GSC_SURVEY_PLATE Comments: Coordinates generated within VTT (aperture=WFC2-FIX). Field includes HIP12668 (V_mag = 10.81) and two additional stars. Read out both WF1 and WF2. 3 NGC4151-POS1 GALAXY, SPIRAL, SEYFERT RA=12H 10M 30.27S +/- 1.0", J2000 V = 11.37+/-0.2 DEC=39D 25' 16.90" +/- 1.0", PLATE-ID=01QY Coordinate Source: GSC_SURVEY_PLATE Comments: Coordinates generated within VTT (Aperture: WFC2-FIX). This is the E field; includes nucleus of N4151 and three bright stars. 4 NGC4151-POS2 GALAXY, SPIRAL, SEYFERT RA=12H 10M 19.60S +/- 1.0", J2000 V = 11.37+/-0.2 DEC=39D 25' 39.94" +/- 1.0", PLATE-ID=01QY Coordinate Source: GSC_SURVEY_PLATE Comments: Coordinates generated within VTT (aperture: WFC2-FIX). This is the middle field (intermediate between POS1 and POS3, and overlapping with both). 5 NGC4151-POS3 GALAXY, SPIRAL, SEYFERT RA=12H 9M 57.08S +/- 1.0", J2000 V = 11.37+/-0.2 DEC=39D 27' 1.91" +/- 1.0", PLATE-ID=01QY Coordinate Source: GSC_SURVEY_PLATE Comments: Coordinates generated within VTT (aperture: WFC1-FIX). This is the W field; includes HIP59295 (V=8.2) and TYC3017-1357-1 (V=11.1). 6 NGC104 CALIBRATION, POINT RA=00H 24M 5S +/- 1", DEC=-72D J2000 V = 19.5+/-.5 SPREAD FUNCTION, 4' 50" +/- 1" SPATIAL DISTORTION TEST, STELLAR CLUSTER, Coordinate Source: GSC_SURVEY_PLATE Comments: This is the (0, 0) position of the field chosen for geometric distortion calibration of WFC (program 9028). 9503( 8) - 10/30/02 15:14 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 37D TO 55D GROUP 01, 02, 03 WITHIN 3 Orbits On Hold Comments: Additional Comments: POS ANG derived from pattern ACS-WFC-DITHER-BOX. At each dither position take a short and long exposure, when possible. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC1068-NUC ACS/WF ACCUM WFC2-FI F550M GAIN=2,SIZEAXIS2=2046,CR-SPLIT=NO 1 0.8 S C X ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC1068-NUC ACS/WF ACCUM WFC2-FI F550M GAIN=2,CR-SPLIT=NO,SIZEAXIS2=2046 1 150 S C X ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC1068-NUC ACS/WF ACCUM WFC2-FI F550M GAIN=2,SIZEAXIS2=2046,CR-SPLIT=NO 1 0.8 S POS TARG 0.248, 0.094 C X Comments: POS TARG from ACS dither pattern 16 ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC1068-NUC ACS/WF ACCUM WFC2-FI F550M GAIN=2,CR-SPLIT=NO 1 300 S POS TARG 0.248, 0.094 C X Comments: POS TARG from ACS dither pattern 16 ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC1068-NUC ACS/WF ACCUM WFC2-FI F550M GAIN=2,SIZEAXIS2=2046,CR-SPLIT=NO 1 0.8 S POS TARG 0.124, 0.233 C X Comments: POS TARG from ACS dither pattern 16 ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC1068-OFF ACS/WF ACCUM WFC2-FI F550M GAIN=2,CR-SPLIT=NO 1 0.8 S C X ------------------------------------------------------------------------------------------------------------------------------------ 9503( 8) - 10/30/02 15:14 - [ 6] Visit: 02 Visit Priority: 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 NGC104 ACS/WF ACCUM WFC F550M CR-SPLIT=NO 1 90 S C ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC104 ACS/WF ACCUM WFC F550M CR-SPLIT=NO 1 90 S POS TARG 0.116, 0.075 C Comments: POS TARG from ACS dither pattern 13 ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC104 ACS/WF ACCUM WFC F550M CR-SPLIT=NO 1 90 S POS TARG 0.231, 0.150 C Comments: POS TARG from ACS dither pattern 13 ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC104 ACS/WF ACCUM WFC F475W CR-SPLIT=NO 1 60 S C ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC104 ACS/WF ACCUM WFC F502N CR-SPLIT=NO 1 340 S C ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC104 ACS/WF ACCUM WFC F658N CR-SPLIT=NO 1 340 S C ------------------------------------------------------------------------------------------------------------------------------------ 9503( 8) - 10/30/02 15:14 - [ 7] Visit: 03 Visit Priority: Visit Requirements: ORIENT 275D TO 285D DROP TO GYRO IF NECESSARY 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 NGC4151-POS ACS/WF ACCUM WFC2-FI F550M CR-SPLIT=NO,GAIN=2 1 60 S 2 C X ------------------------------------------------------------------------------------------------------------------------------------ 20 NGC4151-POS ACS/WF ACCUM WFC2-FI F550M CR-SPLIT=NO,GAIN=2,SIZEAXIS2=2046 1 1.0 S 1 C X ------------------------------------------------------------------------------------------------------------------------------------ 30 NGC4151-POS ACS/WF ACCUM WFC2-FI F550M CR-SPLIT=NO,GAIN=2 1 190 S 1 C X ------------------------------------------------------------------------------------------------------------------------------------ 40 NGC4151-POS ACS/WF ACCUM WFC2-FI F550M CR-SPLIT=NO,GAIN=2,SIZEAXIS2=2046 1 1.0 S POS TARG .248,.268 1 C X Comments: POS TARG from ACS dither pattern 14 ------------------------------------------------------------------------------------------------------------------------------------ 50 NGC4151-POS ACS/WF ACCUM WFC1-FI F502N CR-SPLIT=NO,GAIN=2,SIZEAXIS2=2046 1 1.0 S 3 C X ------------------------------------------------------------------------------------------------------------------------------------ 60 NGC4151-POS ACS/WF ACCUM WFC1-FI F550M CR-SPLIT=NO,GAIN=2 1 2 S 3 C X ------------------------------------------------------------------------------------------------------------------------------------ 9503( 8) - 10/30/02 15:14 - [ 8] Summary Form for Proposal 9503 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC2-FIX WFC WFC1-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters GAIN=2 SIZEAXIS2=2046 CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 37D TO 55D GROUP 01, 02, 03 WITHIN 3 Orbits POS TARG 0.248, 0.094 POS TARG 0.124, 0.233 POS TARG 0.116, 0.075 POS TARG 0.231, 0.150 ORIENT 275D TO 285D DROP TO GYRO IF NECESSARY POS TARG .248,.268 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F550M F475W F502N F658N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC1068-NUC NGC1068-OFF NGC104 NGC4151-POS2 NGC4151-POS1 NGC4151-POS3 ------------------------------------------------------------------------------------------------------------------------------------