17462( 6) - 10-Jun-2024 14:50:09 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 17462 Version: 6 Check-in Time: 10-Jun-2024 14:50:09 STScI Edit Number: 3 Title Evolution of an isolated shock-cloud interaction along the southeastern boundary of the Cygnus Loop supernova remnant ------------------------------------------------------------------------------------ Type Cycle GO 31 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Ravi Sankrit Space Telescope Science Institute Y CoI: Dr. John Charles Raymond Smithsonian Institution Astrophysical N Observatory CoI: Dr. William P. Blair The Johns Hopkins University N CoI: Dr. Mitchell Revalski Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract We propose to use WFC3 narrowband imaging to obtain HST 2nd epoch H-alpha, [S II] and [O III] images of an isolated shock-cloud interaction in the Cygnus Loop that was previously observed in 1994 using WFPC2. The two sets of images separated by over 30 years will allow us to characterize the evolution of the shocked gas in great detail. Proper motions will be measured to an accuracy of better than 1.5 mas/yr. Thus, for well defined filaments and knots, the shock velocities will be determined based on the accurate GAIA-derived distance to the Cygnus Loop (725 +/- 15 pc) to within about 5 km/s. The differences in shock velocities along a filament and at different locations will allow us to estimate the variation in the pre-shock densities that exist within the cloud. Instabilities and shearing in the flow, or the development of turbulence will be seen as changes in the emission morphologies. The brightening of [O III] and [S II] emission relative to H-alpha will indicate that the recombination zone behind the shock front is getting stronger, and conversely the morphologies and brightnesses will remain more or less the same if the shock-front is moving in steady state. The long temporal baseline between observations combined with the high angular resolution of the HST instruments provides a powerful tool for analyzing the various physical processes that drive supernova remnant shock-cloud interactions. ------------------------------------------------------------------------------------ Observations Description ------------------------ Three WFC3/UVIS filters, F656N, F673N and F502N will be used to image a single field in the Cygnus Loop supernova remnant in H-alpha, [S II] and [O III], respectively. The region to be observed is a shock-cloud interaction along the south-east perimeter of the remnant that has been imaged previously by WFPC2. We require all the exposures to be at the same orientation, and have specified them in a single four-orbit visit. For each exposure a standard dither pattern to cover the chip gap plus a sub-pattern to remove cosmic rays and bad pixels have been specified. We have also included a FLASH for each sub-exposure, as recommended. Although the region of interest will be covered at any orientation, there are features near the edges of the field that are critical to include that may require the co-ordinates to be tweaked after the visits have been scheduled in 17462( 6) - 10-Jun-2024 14:50:09 - [ 2] the long-range plan. Once the target is scheduled we request the opportunity to update the target co-ordinates in the Phase II proposal before the visit executes. ------------------------------------------------------------------------------------ 17462( 6) - 10-Jun-2024 14:50:09 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CYGLOOP-SE-C ISM, EMISSION LINE RA=20H56M18.8000S, J2000 V = 35 +/- 0 H-alpha surface brightness LOUD NEBULA, SHOCK FRONT, DEC=+30D22'26.57" 6.0 +/- 0.5 E-15 erg/s/cm2/arcsec2 SNR Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 2 CYGLOOP-SE-C ISM, EMISSION LINE RA=20H56M18.4601S, J2000 V = 35 +/- 0 H-alpha surface brightness LOUD-TWEAK NEBULA, SHOCK FRONT, DEC=+30D22'25.76" 6.0 +/- 0.5 E-15 erg/s/cm2/arcsec2 SNR Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 17462( 6) - 10-Jun-2024 14:50:09 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-GAP-LINE WFC3-UVIS-DITHER-LINE-3PT Pattern_Purpose MOSAIC DITHER Number_Of_Points 2 3 Point_Spacing 2.414 1.485 Line_Spacing Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 85.759 46.84 Angle_Between_Sides Center_Pattern YES NO ------------------------------------------------------------------------------------------------------------------------------------ 17462( 6) - 10-Jun-2024 14:50:09 - [ 5] Visit: 01 (CygLoopSE) Visit Requirements: SCHED 100% 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 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F656N FLASH=20 1 350 S PATTERN 1 1-3 CLOUD S ER see below (2408 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F673N FLASH=20 1 350 S CLOUD S ER see below (2408 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F502N FLASH=20 1 400 S CLOUD S ER see below (2944 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 | ------------------------------------------------------------------------------------------------------------------------------------ CYGLOOP-SE-CLOUD 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 1 none none 1 363.0 S S TER CYGLOOP-SE-CLOUD 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 2 none none 1 363.0 S S TER CYGLOOP-SE-CLOUD 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 3 none none 2 480.0 S S TER CYGLOOP-SE-CLOUD 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 1 none none 3 361.0 S S TER CYGLOOP-SE-CLOUD 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 2 none none 3 361.0 S S TER CYGLOOP-SE-CLOUD 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 3 none none 4 480.0 S S TER CYGLOOP-SE-CLOUD 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 1 none none 1 363.0 S S TER CYGLOOP-SE-CLOUD 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 2 none none 1 363.0 S S TER CYGLOOP-SE-CLOUD 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 3 none none 2 480.0 S S TER CYGLOOP-SE-CLOUD 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 1 none none 3 361.0 S S TER CYGLOOP-SE-CLOUD 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 2 none none 3 361.0 S S TER CYGLOOP-SE-CLOUD 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 3 none none 4 480.0 S S TER 17462( 6) - 10-Jun-2024 14:50:09 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CYGLOOP-SE-CLOUD 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 1 none none 1 413.0 S S TER CYGLOOP-SE-CLOUD 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 2 none none 2 530.0 S S TER CYGLOOP-SE-CLOUD 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 3 none none 2 530.0 S S TER CYGLOOP-SE-CLOUD 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 1 none none 3 411.0 S S TER CYGLOOP-SE-CLOUD 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 2 none none 4 530.0 S S TER CYGLOOP-SE-CLOUD 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 3 none none 4 530.0 S S TER 17462( 6) - 10-Jun-2024 14:50:09 - [ 7] Visit: 51 (CygLoopSE) Visit Requirements: SCHED 100% On Hold Comments: Additional Comments: HOPR repeat of visit 01. 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 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F656N FLASH=20 1 350 S PATTERN 1 1-3 CLOUD-TWEAK S ER see below (2408 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F673N FLASH=20 1 350 S CLOUD-TWEAK S ER see below (2408 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F502N FLASH=20 1 400 S CLOUD-TWEAK S ER see below (2944 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 | ------------------------------------------------------------------------------------------------------------------------------------ CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 1 none none 1 363.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 2 none none 1 363.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 3 none none 2 480.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 1 none none 3 361.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 2 none none 3 361.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 3 none none 4 480.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 1 none none 1 363.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 2 none none 1 363.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 3 none none 2 480.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 1 none none 3 361.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 2 none none 3 361.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 3 none none 4 480.0 S EAK S TER 17462( 6) - 10-Jun-2024 14:50:09 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 1 none none 1 413.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 2 none none 2 530.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 3 none none 2 530.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 1 none none 3 411.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 2 none none 4 530.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 3 none none 4 530.0 S EAK S TER 17462( 6) - 10-Jun-2024 14:50:09 - [ 9] Visit: 52 (CygLoopSE) Visit Requirements: SCHED 100% On Hold Comments: Additional Comments: HOPR repeat of visit 51. 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 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F656N FLASH=20 1 350 S GS ACQ SCENARIO BASE1O3; CLOUD-TWEAK S ER see below PATTERN 1 1-3 (2408 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F673N FLASH=20 1 350 S CLOUD-TWEAK S ER see below (2408 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 CYGLOOP-SE- WFC3/UVI ACCUM UVIS-CENT F502N FLASH=20 1 400 S CLOUD-TWEAK S ER see below (2944 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 | ------------------------------------------------------------------------------------------------------------------------------------ CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 1 none none 1 363.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 2 none none 1 363.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 1 3 none none 2 480.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 1 none none 3 361.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 2 none none 3 361.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 1 WFC3/UVI ACCUM UVIS-CEN F656N 2 3 none none 4 480.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 1 none none 1 363.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 2 none none 1 363.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 1 3 none none 2 480.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 1 none none 3 361.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 2 none none 3 361.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 2 WFC3/UVI ACCUM UVIS-CEN F673N 2 3 none none 4 480.0 S EAK S TER 17462( 6) - 10-Jun-2024 14:50:09 - [ 10] 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 | ------------------------------------------------------------------------------------------------------------------------------------ CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 1 none none 1 413.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 2 none none 2 530.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 1 3 none none 2 530.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 1 none none 3 411.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 2 none none 4 530.0 S EAK S TER CYGLOOP-SE-CLOUD-TW 3 WFC3/UVI ACCUM UVIS-CEN F502N 2 3 none none 4 530.0 S EAK S TER 17462( 6) - 10-Jun-2024 14:50:09 - [ 11] Summary Form for Proposal 17462 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=20 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1O3, PATTERN 1 1-3, SCHED 100% ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F502N, F656N, F673N ------------------------------------------------------------------------------------------------------------------------------------ Target Names CYGLOOP-SE-CLOUD, CYGLOOP-SE-CLOUD-TWEAK ------------------------------------------------------------------------------------------------------------------------------------