17783( 2) - 12-Aug-2024 16:43:19 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17783 Version: 2 Check-in Time: 12-Aug-2024 16:43:19 STScI Edit Number: 0 Title HST Polarimetry and Proper Motions of the Pictor A Hotspot ------------------------------------------------------------------------------------ Type Cycle GO 32 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Eileen T Meyer University of Maryland Baltimore County Y CoI: Dr. Ioannis Liodakis NASA Marshall Space Flight Center N CoI: Prof. Eric S. Perlman Florida Institute of Technology N CoI: Dr. Markos Georganopoulos University of Maryland Baltimore County N CoI: Dr. Jay Anderson Space Telescope Science Institute N CoI: Dr. Karthik Reddy Solipuram Arizona State University N CoI: Prof. Judd Bowman Arizona State University N ------------------------------------------------------------------------------------ Abstract The X-ray emission mechanism and particle acceleration mechanism in kpc-scale AGN jets is still poorly understood. Nearby radio galaxy Pictor A hosts one of the nearest and brightest X-ray emitting jets, and is a highly valuable target for long-term monitoring and study. The jet has been deeply observed in the X-rays with Chandra, with a total exposure of nearly 0.5 Ms over 14 years. These observations revealed that the X-ray jet and hotspot unexpectedly vary on timescales as short as a few months to years in both the soft and hard X-rays, which places extreme constraints on the particle acceleration mechanism. The western hotspot of Pictor A, as the brightest in the sky with sufficient spatial separation from the core, has been recently detected in the hard X-rays with NuSTAR and was also approved for a large 2 Ms observation with IXPE in the first GO cycle, to measure its X-ray polarization. We propose HST optical/UV and polarization imaging of the jet and western hotspot of Pictor A. The proposed observations are highly complimentary and will extend the longest time baselines of optical imaging to nearly 30 years, enabling a range of investigations into variability, proper motions, and spectral evolution of the source. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program is focused primarily on the Western hotspot of Pictor A, which is 4' from the central nucleus. The entire size of the source is 7.6 arcminutes between terminal hotspots. The first observing mode is ACS/WFC Polarization, where the hotspot will be positioned near the center of the active dector region for the polarization filters. The observation will combine the linear polarization filters (POL0V, POL60V, POL120V), two orbits each, 3 exposures/orbit, with wide-V F606W. The F606W filter is by far the most efficient in terms of throughput in combination with the polarizers. The second visit will be non-polarization imaging with ACS/WFC in the same filter as used for the polarization (F606W) to aid in the image alignment and 17783( 2) - 12-Aug-2024 16:43:19 - [ 2] also to provide a baseline for a long-term optical proper motions program. We use ORIENT constraints to ensure the hotspot is on the detector with the jet falling on the diagonal so that the jet and core (host galaxy) are both captured in all images. We used a WFCCENTER pointing which is midway between the core and the hotspot -- the finding charts do not show the hotspot because of the size of the source. All pointing/orient constraints have been checked using actual HST images to ensure good target placement. The third visit/mode will be two orbits of WFC3/UVIS imaging in the F225W UV filter. The pointing will be somewhat similar to that used for the V-band imaging, in that we choose a point along the line of the jet to the hotspot and ORIENT constraints, in order to maximize the extent of the jet on the detector. Because of the smaller FOV of the UVIS detectors, it will not be possible to include the inner jet and nucleus of Pictor A in the observations, and the finding charts do not show the hotspot. For all observations we use appropriate dithering to sample the PSF and cover the chip gap, if applicable. ------------------------------------------------------------------------------------ 17783( 2) - 12-Aug-2024 16:43:19 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PICTORA-WEST GALAXY, HOTSPOT, JET RA=05H19M28.0000S, J2000 V = 16.45 -POL DEC=-45D46'0.00" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 PICTORA-WEST GALAXY, HOTSPOT, JET RA=05H19M36.2877S, J2000 V = 16.45 -V DEC=-45D46'12.21" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 3 PICTORA-WEST GALAXY, HOTSPOT, JET RA=05H19M33.7626S, J2000 V = 16.45 -UV DEC=-45D46'3.16" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 17783( 2) - 12-Aug-2024 16:43:19 - [ 4] Visit: 01 (ACS Polarization) Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0, 0 T-POL POL0V S) ------------------------------------------------------------------------------------------------------------------------------------ 2 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0.20646, T-POL POL0V S) 0.14754 ------------------------------------------------------------------------------------------------------------------------------------ 3 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0.41257, T-POL POL0V S) 0.24554 ------------------------------------------------------------------------------------------------------------------------------------ 4 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.12505, T-POL POL0V S) 0.34768 ------------------------------------------------------------------------------------------------------------------------------------ 5 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.33111, T-POL POL0V S) 0.42753 ------------------------------------------------------------------------------------------------------------------------------------ 6 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.53746 , T-POL POL0V S) 0.56020 ------------------------------------------------------------------------------------------------------------------------------------ 7 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0, 0 T-POL POL60V S) ------------------------------------------------------------------------------------------------------------------------------------ 8 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0, 0 T-POL POL60V S) ------------------------------------------------------------------------------------------------------------------------------------ 9 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0.20646, T-POL POL60V S) 0.14754 ------------------------------------------------------------------------------------------------------------------------------------ 10 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0.41257, T-POL POL60V S) 0.24554 ------------------------------------------------------------------------------------------------------------------------------------ 11 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.12505, T-POL POL60V S) 0.34768 ------------------------------------------------------------------------------------------------------------------------------------ 12 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.33111, T-POL POL60V S) 0.42753 ------------------------------------------------------------------------------------------------------------------------------------ 13 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.53746 , T-POL POL120V S) 0.56020 ------------------------------------------------------------------------------------------------------------------------------------ 14 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0.20646, T-POL POL120V S) 0.14754 ------------------------------------------------------------------------------------------------------------------------------------ 17783( 2) - 12-Aug-2024 16:43:19 - [ 5] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 705 S (705 POS TARG 0.41257, T-POL POL120V S) 0.24554 ------------------------------------------------------------------------------------------------------------------------------------ 16 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.12505, T-POL POL120V S) 0.34768 ------------------------------------------------------------------------------------------------------------------------------------ 17 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.33111, T-POL POL120V S) 0.42753 ------------------------------------------------------------------------------------------------------------------------------------ 18 PICTORA-WES ACS/WFC ACCUM WFC2 F606W, 1 738 S (738 POS TARG 0.53746 , T-POL POL120V S) 0.56020 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ PICTORA-WEST-POL 1 ACS/WFC ACCUM WFC2 F606W, none none none none 1 N/A POL0V PICTORA-WEST-POL 2 ACS/WFC ACCUM WFC2 F606W, none none none none 1 N/A POL0V PICTORA-WEST-POL 3 ACS/WFC ACCUM WFC2 F606W, none none none none 1 N/A POL0V PICTORA-WEST-POL 4 ACS/WFC ACCUM WFC2 F606W, none none none none 2 N/A POL0V PICTORA-WEST-POL 5 ACS/WFC ACCUM WFC2 F606W, none none none none 2 N/A POL0V PICTORA-WEST-POL 6 ACS/WFC ACCUM WFC2 F606W, none none none none 2 N/A POL0V PICTORA-WEST-POL 7 ACS/WFC ACCUM WFC2 F606W, none none none none 3 N/A POL60V PICTORA-WEST-POL 8 ACS/WFC ACCUM WFC2 F606W, none none none none 3 N/A POL60V PICTORA-WEST-POL 9 ACS/WFC ACCUM WFC2 F606W, none none none none 3 N/A POL60V PICTORA-WEST-POL 10 ACS/WFC ACCUM WFC2 F606W, none none none none 4 N/A POL60V PICTORA-WEST-POL 11 ACS/WFC ACCUM WFC2 F606W, none none none none 4 N/A POL60V PICTORA-WEST-POL 12 ACS/WFC ACCUM WFC2 F606W, none none none none 4 N/A POL60V PICTORA-WEST-POL 13 ACS/WFC ACCUM WFC2 F606W, none none none none 5 N/A POL120V PICTORA-WEST-POL 14 ACS/WFC ACCUM WFC2 F606W, none none none none 5 N/A POL120V 17783( 2) - 12-Aug-2024 16:43:19 - [ 6] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ PICTORA-WEST-POL 15 ACS/WFC ACCUM WFC2 F606W, none none none none 5 N/A POL120V PICTORA-WEST-POL 16 ACS/WFC ACCUM WFC2 F606W, none none none none 6 N/A POL120V PICTORA-WEST-POL 17 ACS/WFC ACCUM WFC2 F606W, none none none none 6 N/A POL120V PICTORA-WEST-POL 18 ACS/WFC ACCUM WFC2 F606W, none none none none 6 N/A POL120V 17783( 2) - 12-Aug-2024 16:43:19 - [ 7] Visit: 02 (ACS V-band Imaging) Visit Requirements: ORIENT 144D TO 151 D; ORIENT 323D TO 332 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PICTORA-WES ACS/WFC ACCUM WFCENTER F606W 1 365 S (365 T-V S) ------------------------------------------------------------------------------------------------------------------------------------ 2 PICTORA-WES ACS/WFC ACCUM WFCENTER F606W 1 365 S (365 POS TARG 0.15914, T-V S) 0.23969 ------------------------------------------------------------------------------------------------------------------------------------ 3 PICTORA-WES ACS/WFC ACCUM WFCENTER F606W 1 365 S (365 POS TARG 0.31641, T-V S) 3.08319 ------------------------------------------------------------------------------------------------------------------------------------ 4 PICTORA-WES ACS/WFC ACCUM WFCENTER F606W 1 365 S (365 POS TARG 0.07990, T-V S) 4.19413 ------------------------------------------------------------------------------------------------------------------------------------ 5 PICTORA-WES ACS/WFC ACCUM WFCENTER F606W 1 365 S (365 POS TARG 0.28771, T-V S) 5.28896 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ PICTORA-WEST-V 1 ACS/WFC ACCUM WFCENTER F606W none none none none 1 N/A PICTORA-WEST-V 2 ACS/WFC ACCUM WFCENTER F606W none none none none 1 N/A PICTORA-WEST-V 3 ACS/WFC ACCUM WFCENTER F606W none none none none 1 N/A PICTORA-WEST-V 4 ACS/WFC ACCUM WFCENTER F606W none none none none 1 N/A PICTORA-WEST-V 5 ACS/WFC ACCUM WFCENTER F606W none none none none 1 N/A 17783( 2) - 12-Aug-2024 16:43:19 - [ 8] Visit: 03 (UV Imaging) Visit Requirements: ORIENT 355D TO 12 D; ORIENT 265D TO 285 D; ORIENT 176D TO 192 D; ORIENT 80D TO 105 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 PICTORA-WES WFC3/UVI ACCUM UVIS-CENT F225W FLASH=18 1 564 S (564 POS TARG 0, -2.8 T-UV S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 2 PICTORA-WES WFC3/UVI ACCUM UVIS-CENT F225W FLASH=18 1 564 S (564 POS TARG 0.1392, -1.412 T-UV S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 3 PICTORA-WES WFC3/UVI ACCUM UVIS-CENT F225W FLASH=18 1 564 S (564 POS TARG 0.25856, 0.0988 T-UV S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 4 PICTORA-WES WFC3/UVI ACCUM UVIS-CENT F225W FLASH=18 1 564 S (564 POS TARG 0.0804, 1.4644 T-UV S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 5 PICTORA-WES WFC3/UVI ACCUM UVIS-CENT F225W FLASH=18 1 558 S (558 POS TARG 0.406, -2.7596 T-UV S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 6 PICTORA-WES WFC3/UVI ACCUM UVIS-CENT F225W FLASH=18 1 558 S (558 POS TARG 0.5452, -1.3716 T-UV S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 7 PICTORA-WES WFC3/UVI ACCUM UVIS-CENT F225W FLASH=18 1 558 S (558 POS TARG 0.664, 0.1388 T-UV S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 8 PICTORA-WES WFC3/UVI ACCUM UVIS-CENT F225W FLASH=18 1 558 S (558 POS TARG 0.4864, 1.5048 T-UV S ER S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ PICTORA-WEST-UV 1 WFC3/UVI ACCUM UVIS-CEN F225W none none none none 1 N/A S TER PICTORA-WEST-UV 2 WFC3/UVI ACCUM UVIS-CEN F225W none none none none 1 N/A S TER PICTORA-WEST-UV 3 WFC3/UVI ACCUM UVIS-CEN F225W none none none none 1 N/A S TER PICTORA-WEST-UV 4 WFC3/UVI ACCUM UVIS-CEN F225W none none none none 1 N/A S TER PICTORA-WEST-UV 5 WFC3/UVI ACCUM UVIS-CEN F225W none none none none 2 N/A S TER PICTORA-WEST-UV 6 WFC3/UVI ACCUM UVIS-CEN F225W none none none none 2 N/A S TER 17783( 2) - 12-Aug-2024 16:43:19 - [ 9] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ PICTORA-WEST-UV 7 WFC3/UVI ACCUM UVIS-CEN F225W none none none none 2 N/A S TER PICTORA-WEST-UV 8 WFC3/UVI ACCUM UVIS-CEN F225W none none none none 2 N/A S TER 17783( 2) - 12-Aug-2024 16:43:19 - [ 10] Summary Form for Proposal 17783 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER, WFC2, WFCENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=18 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 144D TO 151 D, ORIENT 176D TO 192 D, ORIENT 265D TO 285 D, ORIENT 323D TO 332 D, ORIENT 355D TO 12 D, ORIENT 80D TO 105 D, POS TARG 0.12505, 0.34768, POS TARG 0.41257, 0.24554, POS TARG 0, -2.8, POS TARG 0, 0, POS TARG 0.07990, 4.19413, POS TARG 0.0804, 1.4644, POS TARG 0.1392, -1.412, POS TARG 0.15914, 0.23969, POS TARG 0.20646, 0.14754, POS TARG 0.25856, 0.0988, POS TARG 0.28771, 5.28896, POS TARG 0.31641, 3.08319, POS TARG 0.33111, 0.42753, POS TARG 0.406, -2.7596, POS TARG 0.4864, 1.5048, POS TARG 0.53746 , 0.56020, POS TARG 0.5452, -1.3716, POS TARG 0.664, 0.1388 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F225W, F606W, POL0V, POL120V, POL60V ------------------------------------------------------------------------------------------------------------------------------------ Target Names PICTORA-WEST-POL, PICTORA-WEST-UV, PICTORA-WEST-V ------------------------------------------------------------------------------------------------------------------------------------