15191( 4) - 12-Dec-2018 15:14:09 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15191 Version: 4 Check-in Time: 12-Dec-2018 15:14:09 STScI Edit Number: 1 Title Monitoring an Internal Shock Collision in Action in 3C 264 ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Eileen T Meyer University of Maryland Baltimore County Y CoI: Dr. Markos Georganopoulos University of Maryland Baltimore County N CoI: Dr. William B. Sparks SETI Institute N CoI: Dr. John A. Biretta Eureka Scientific Inc. N CoI: Dr. Roeland P. van der Marel Space Telescope Science Institute N CoI: Dr. Jay Anderson Space Telescope Science Institute N CoI: Dr. Sangmo Tony Sohn Space Telescope Science Institute N CoI: Dr. Marco Chiaberge Space Telescope Science Institute - ESA N CoI: Dr. Colin A. Norman The Johns Hopkins University N CoI: Prof. Eric S. Perlman Florida Institute of Technology N ------------------------------------------------------------------------------------ Abstract 3C264 is a nearby radio galaxy with a prominent optical jet. Recent HST observations (May 2014) have revealed not only the fastest-ever superluminal speed (on kpc scales) of 7c for knot B, but also that knot B is in the very early stages of a collision with slow-moving downstream knot C (Meyer et al. 2015, Nature). This remarkable discovery represents the first strong evidence for the "internal shock" model for particle acceleration, a mechanism proposed to explain sources as diverse as gamma-ray bursts, microquasars, and jetted AGN. While a popular theoretical framework, such a collision has never actually been observed directly in any astrophysical object. Our recent HST imaging has captured the collision in its incipient stages, thus we have a unique opportunity to monitor a major shock collision as it unfolds. We propose 2 epochs of WFC3/UVIS (near-UV, B, and I band) imaging to monitor the optical-UV spectral energy distribution for the colliding knots and continue spatial proper motion measurements of the jet over the next 2-3 years. We also request 1 orbit of polarimetry in F606W with ACS/WFC in each epoch to monitor the polarization structure in the jet for changes as a result of the collision. The collision is expected to manifest in brightening and hardening of the optical spectrum and increasing polarization over the next several years, and our observations will allow us to evaluate the applicability, efficiency and physical characterization of the internal shock mechanism. ------------------------------------------------------------------------------------ Observations Description ------------------------ Observations are of an optical jet approximately 2" long in the northeast direction, as part of a monitoring proposal for flaring behavior (this is the follow-up of an identical set of observations in Cycle 23). The field of view is dominated by the host galaxy, a nearby elliptical. The observations consist of two visits: the first is WFC3/UVIS imaging in three filters (F475W, F814W splitting the first orbit, F225W in the second orbit). The second visit is ACS/WFC polarimetry in F606W filter. Orient constraints are specified to avoid 15191( 4) - 12-Dec-2018 15:14:09 - [ 2] any risk of the central nucleus from producing diffraction spikes that run over the jet. Secondly, we request that the observations occur after Feb 2018 in order to evaluate the flux level of the jet with an even cadence (previous observations were in May 2014 and April 2016, so ideally these would occur in Spring/Summer of 2018). ------------------------------------------------------------------------------------ 15191( 4) - 12-Dec-2018 15:14:09 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 3C264 GALAXY, ELLIPTICAL, RA=11H45M5.0090S, J2000 V = 13.97 JET, NUCLEUS, RADIO DEC=+19D36'22.74" GALAXY Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 15191( 4) - 12-Dec-2018 15:14:09 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 0.135 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 46.84 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 3.011 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.28 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 15191( 4) - 12-Dec-2018 15:14:09 - [ 5] Visit: 01 (WFC3/UVIS imaging) Visit Requirements: ORIENT 25D TO 55 D; ORIENT 110D TO 145 D; ORIENT 290D TO 325 D; AFTER 24-MAR-2018:00:00:00 On Hold Comments: Additional Comments: We used a 3-point dithering pattern for the sets of F475W (3 exp) and F814W (3 exp) observations in the first epoch. We used a 4-point dithering pattern for the 4 F225W exposures in the second orbit. Orient constraints are specified to avoid any risk of the central nucleus from producing diffraction spikes that run over the jet. We request observations in late 2015 in order to evaluate if the flux from the jet is rapidly increasing (i.e. flaring). POS TARGS are also used to put the target somewhat closer to the readout corner to minimize CTE. 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 3C264 WFC3/UVI ACCUM UVIS1 F475W FLASH=6 1 365 S POS TARG 30, 10; GS ACQ S (1095 S) SCENARIO BASE1B3; PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 3C264 WFC3/UVI ACCUM UVIS1 F814W FLASH=5 1 365 S POS TARG 30, 10; PATTERN S (1095 S) 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 3C264 WFC3/UVI ACCUM UVIS1 F225W FLASH=10 1 645 S POS TARG 30, 10; PATTERN S (2580 S) 2 3 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 3C264 1 WFC3/UVI ACCUM UVIS1 F475W 1 none none none 1 N/A S 3C264 1 WFC3/UVI ACCUM UVIS1 F475W 2 none none none 1 N/A S 3C264 1 WFC3/UVI ACCUM UVIS1 F475W 3 none none none 1 N/A S 3C264 2 WFC3/UVI ACCUM UVIS1 F814W 1 none none none 1 N/A S 3C264 2 WFC3/UVI ACCUM UVIS1 F814W 2 none none none 1 N/A S 3C264 2 WFC3/UVI ACCUM UVIS1 F814W 3 none none none 1 N/A S 3C264 3 WFC3/UVI ACCUM UVIS1 F225W 1 none none none 2 N/A S 3C264 3 WFC3/UVI ACCUM UVIS1 F225W 2 none none none 2 N/A S 3C264 3 WFC3/UVI ACCUM UVIS1 F225W 3 none none none 2 N/A S 3C264 3 WFC3/UVI ACCUM UVIS1 F225W 4 none none none 2 N/A S 15191( 4) - 12-Dec-2018 15:14:09 - [ 6] Visit: 02 (ACS Polariz.) Visit Requirements: ORIENT 40D TO 85 D; ORIENT 128D TO 170 D; ORIENT 215D TO 270 D; ORIENT 305D TO 345 D; AFTER 24-MAR-2018:00:00:00 On Hold Comments: Additional Comments: 1 orbit of ACS polarization in F606W filter. The observations cover the three polarization angle filters, with two exposures each, using a 2-point dither pattern to improve image quality and mitigate cosmic ray artifacts. Orient constraints are specified to avoid any risk of the central nucleus from producing diffraction spikes that run over the jet. We request observations in late 2015 in order to evaluate if the flux from the jet is rapidly increasing (i.e. flaring). 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 3C264 ACS/WFC ACCUM WFC1 F606W, 1 300 S (600 POS TARG 0, 0; PATTERN 3 POL0V S) 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 3C264 ACS/WFC ACCUM WFC1 F606W, 1 300 S (600 POS TARG 0, 0; PATTERN 3 POL120V S) 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 3C264 ACS/WFC ACCUM WFC1 F606W, 1 300 S (600 POS TARG 0, 0; PATTERN 3 POL60V S) 3 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 3C264 1 ACS/WFC ACCUM WFC1 F606W, 1 none none none 1 N/A POL0V 3C264 1 ACS/WFC ACCUM WFC1 F606W, 2 none none none 1 N/A POL0V 3C264 2 ACS/WFC ACCUM WFC1 F606W, 1 none none none 1 N/A POL120V 3C264 2 ACS/WFC ACCUM WFC1 F606W, 2 none none none 1 N/A POL120V 3C264 3 ACS/WFC ACCUM WFC1 F606W, 1 none none none 1 N/A POL60V 3C264 3 ACS/WFC ACCUM WFC1 F606W, 2 none none none 1 N/A POL60V 15191( 4) - 12-Dec-2018 15:14:09 - [ 7] Visit: 51 (WFC3/UVIS imaging) Visit Requirements: ORIENT 25D TO 55 D; ORIENT 110D TO 145 D; ORIENT 290D TO 325 D; AFTER 24-MAR-2018:00:00:00 On Hold Comments: Additional Comments: This is a resubmission of failed visit 01 (see HOPR 91044). We used a 3-point dithering pattern for the sets of F475W (3 exp) and F814W (3 exp) observations in the first epoch. We used a 4-point dithering pattern for the 4 F225W exposures in the second orbit. Orient constraints are specified to avoid any risk of the central nucleus from producing diffraction spikes that run over the jet. We request observations in late 2015 in order to evaluate if the flux from the jet is rapidly increasing (i.e. flaring). POS TARGS are also used to put the target somewhat closer to the readout corner to minimize CTE. 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 3C264 WFC3/UVI ACCUM UVIS1 F475W FLASH=6 1 355 S POS TARG 30, 10; GS ACQ S (1065 S) SCENARIO BASE1B3; PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 3C264 WFC3/UVI ACCUM UVIS1 F814W FLASH=5 1 355 S POS TARG 30, 10; PATTERN S (1065 S) 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 3C264 WFC3/UVI ACCUM UVIS1 F225W FLASH=10 1 611 S POS TARG 30, 10; PATTERN S (2444 S) 2 3 ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ 3C264 1 WFC3/UVI ACCUM UVIS1 F475W 1 none none none 1 N/A S 3C264 1 WFC3/UVI ACCUM UVIS1 F475W 2 none none none 1 N/A S 3C264 1 WFC3/UVI ACCUM UVIS1 F475W 3 none none none 1 N/A S 3C264 2 WFC3/UVI ACCUM UVIS1 F814W 1 none none none 1 N/A S 3C264 2 WFC3/UVI ACCUM UVIS1 F814W 2 none none none 1 N/A S 3C264 2 WFC3/UVI ACCUM UVIS1 F814W 3 none none none 1 N/A S 3C264 3 WFC3/UVI ACCUM UVIS1 F225W 1 none none none 2 N/A S 3C264 3 WFC3/UVI ACCUM UVIS1 F225W 2 none none none 2 N/A S 3C264 3 WFC3/UVI ACCUM UVIS1 F225W 3 none none none 2 N/A S 15191( 4) - 12-Dec-2018 15:14:09 - [ 8] 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 | ------------------------------------------------------------------------------------------------------------------------------------ 3C264 3 WFC3/UVI ACCUM UVIS1 F225W 4 none none none 2 N/A S 15191( 4) - 12-Dec-2018 15:14:09 - [ 9] Summary Form for Proposal 15191 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS1, WFC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=10, FLASH=5, FLASH=6 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements AFTER 24-MAR-2018:00:00:00, GS ACQ SCENARIO BASE1B3, ORIENT 110D TO 145 D, ORIENT 128D TO 170 D, ORIENT 215D TO 270 D, ORIENT 25D TO 55 D, ORIENT 290D TO 325 D, ORIENT 305D TO 345 D, ORIENT 40D TO 85 D, PATTERN 1 1, PATTERN 1 2, PATTERN 2 3, PATTERN 3 1, PATTERN 3 2, PATTERN 3 3, POS TARG 0, 0, POS TARG 30, 10 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F225W, F475W, F606W, F814W, POL0V, POL120V, POL60V ------------------------------------------------------------------------------------------------------------------------------------ Target Names 3C264 ------------------------------------------------------------------------------------------------------------------------------------