15515( 4) - 06-Dec-2018 15:22:54 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15515 Version: 4 Check-in Time: 06-Dec-2018 15:22:54 STScI Edit Number: 0 Title An HST Survey of Cassiopeia A's Reverse Shock, High-Velocity Ejecta, and Shocked Clouds of Pre-SN Mass Loss ------------------------------------------------------------------------------------ Type Cycle GO 26 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Robert A. Fesen Dartmouth College Y CoI: Dr. Dan Milisavljevic Purdue University N CoI: Dr. Daniel J. Patnaude Smithsonian Institution Astrophysical N Observatory ------------------------------------------------------------------------------------ Abstract The young Galactic supernova remnant Cassiopeia A (Cas A) provides us with the clearest look at the properties and explosion dynamics of a high mass, core-collapse supernova (CCSN). With an explosion date around 1670, Cas A is the youngest Galactic core-collapse SNR known and, at an estimated distance of 3.4 kpc, it is also among the closest. Cas A's main shell ejecta knots are typically 0.1 - 0.5 arcsec in size and can show emission and morphological changes on timescales of just a few months. No other remnant, with the exception of SN 1987A, shows such rapid optical changes across large portions of its structure. Here we propose a new, complete optical survey of Cas A, the first since 2004, in order to measure the velocity and asymmetry of Cas A's reverse shock front across the whole remnant and map the distribution of its high-velocity outer ejecta, particularly in regions which align to the motion of the central compact source. Halpha images of the remnant's shocked CSM clumps will also provide strong tests of shock-cloud models across a broad range of cloud densities and sizes. These data will constitute a rich and unique archive both for Cas A and the general study of high mass CCSNe. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program is to image the young supernova remnant, Cassiopeia A (Cas A) in three filters: F475W, F625W, and F658N. Nine separate pointings are need in order to cover the entire remnant images. Images in the three filters will be taken at each pointing during one CVZ orbit, totaling nine CVZ orbits. A second set of identical images will be taken roughly one year apart in Cycle 26. The second epoch images is required to discern ejecta knots from stars or distant galaxies via their high proper motions. Cas A lies at the very southern edge of the HST's Continous Viewing Zone (CVZ) and the use of the full 96 minute HST orbit and hence observing time allows for a much more compact and efficient observing program. Similar CVZ imageing programs of Cas A have been done in the past, despite the few days that Cas A is observable in Hubble's CVZ. 15515( 4) - 06-Dec-2018 15:22:54 - [ 2] Note: We have decided to omit the H-alpha imaging in this second set of images and concentrate on the F625W images. This allows two extra images for each target region plus longer exposure times (712 sec vs 510 sec) to obtain much deeper images. NOTE: Revision 4: Nov 21, 2018: Have increased the exposure times from 712 to 730 sec for all targets, and have revised the nine target locations in order to increase visibility of the remnant's outer ejecta knots relative to previous HST images. ------------------------------------------------------------------------------------ 15515( 4) - 06-Dec-2018 15:22:54 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 CAS-A-NE ISM, EJECTA, EMISSION RA=23H23M52.2000S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D50'55.00" FRONT, SNR Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 2 CAS-A-NORTH ISM, EJECTA, EMISSION RA=23H23M33.6500S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D50'45.00" FRONT, SNR Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 3 CAS-A-NW ISM, EJECTA, EMISSION RA=23H23M15.0000S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D50'40.00" FRONT, SNR Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 4 CAS-A-EAST ISM, EJECTA, EMISSION RA=23H23M48.5000S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D49'20.00" FRONT, SNR Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 5 CAS-A-CENTER ISM, EJECTA, EMISSION RA=23H23M29.4700S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D49'10.00" FRONT, SNR Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 6 CAS-A-WEST ISM, EJECTA, EMISSION RA=23H23M10.3500S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D49'10.00" FRONT, SNR Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 7 CAS-A-SE ISM, EJECTA, EMISSION RA=23H23M44.0000S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D47'3.00" FRONT, SNR Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 8 CAS-A-SOUTH ISM, EJECTA, EMISSION RA=23H23M25.7000S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D46'55.00" FRONT, SNR Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 9 CAS-A-SW ISM, EJECTA, EMISSION RA=23H23M7.5000S, J2000 V = 17 LINE NEBULA, SHOCK DEC=+58D46'50.00" FRONT, SNR Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 15515( 4) - 06-Dec-2018 15:22:54 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-MOS-DITH-LINE WFC3-UVIS-MOS-DITH-LINE Pattern_Purpose MOSAIC DITHER Number_Of_Points 2 3 Point_Spacing 2.4 0.119 Line_Spacing Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 85.754 33.606 Angle_Between_Sides Center_Pattern YES NO ------------------------------------------------------------------------------------------------------------------------------------ 15515( 4) - 06-Dec-2018 15:22:54 - [ 5] Visit: 01 Visit Requirements: CVZ; ORIENT 41.0D TO 42.0 D; ORIENT 131.0D TO 132.0 D; ORIENT 221.0D TO 222.0 D; ORIENT 311.0D TO 312.0 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 CAS-A-NE WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 1 S ER (4380 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CAS-A-EAST WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 2 S ER (4380 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 CAS-A-SE WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 3 S ER (4380 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 | ------------------------------------------------------------------------------------------------------------------------------------ CAS-A-NE 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 1 N/A S TER CAS-A-NE 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 1 N/A S TER CAS-A-NE 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 1 N/A S TER CAS-A-NE 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 1 N/A S TER CAS-A-NE 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 1 N/A S TER CAS-A-NE 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 1 N/A S TER CAS-A-EAST 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 1 N/A S TER CAS-A-EAST 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 2 N/A S TER CAS-A-EAST 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 2 N/A S TER CAS-A-EAST 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 2 N/A S TER CAS-A-EAST 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 2 N/A S TER CAS-A-EAST 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 2 N/A S TER CAS-A-SE 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 2 N/A S TER 15515( 4) - 06-Dec-2018 15:22:54 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CAS-A-SE 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 3 N/A S TER CAS-A-SE 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 3 N/A S TER CAS-A-SE 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 3 N/A S TER CAS-A-SE 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 3 N/A S TER CAS-A-SE 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 3 N/A S TER 15515( 4) - 06-Dec-2018 15:22:54 - [ 7] Visit: 02 Visit Requirements: CVZ; SAME ORIENT AS 01 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 CAS-A-NORTH WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 1 S ER (4380 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CAS-A-CENTE WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 2 R S ER (4380 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 CAS-A-SOUTH WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 3 S ER (4380 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 | ------------------------------------------------------------------------------------------------------------------------------------ CAS-A-NORTH 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 1 N/A S TER CAS-A-NORTH 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 1 N/A S TER CAS-A-NORTH 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 1 N/A S TER CAS-A-NORTH 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 1 N/A S TER CAS-A-NORTH 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 1 N/A S TER CAS-A-NORTH 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 1 N/A S TER CAS-A-CENTER 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 1 N/A S TER CAS-A-CENTER 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 2 N/A S TER CAS-A-CENTER 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 2 N/A S TER CAS-A-CENTER 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 2 N/A S TER CAS-A-CENTER 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 2 N/A S TER CAS-A-CENTER 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 2 N/A S TER CAS-A-SOUTH 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 2 N/A S TER 15515( 4) - 06-Dec-2018 15:22:54 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CAS-A-SOUTH 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 3 N/A S TER CAS-A-SOUTH 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 3 N/A S TER CAS-A-SOUTH 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 3 N/A S TER CAS-A-SOUTH 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 3 N/A S TER CAS-A-SOUTH 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 3 N/A S TER 15515( 4) - 06-Dec-2018 15:22:54 - [ 9] Visit: 03 Visit Requirements: CVZ; SAME ORIENT AS 01 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 CAS-A-NW WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 1 S ER (4380 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 CAS-A-WEST WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 2 S ER (4380 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 CAS-A-SW WFC3/UVI ACCUM UVIS-CENT F625W CR-SPLIT=NO 1 730 S PATTERN 1 3 S ER (4380 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 | ------------------------------------------------------------------------------------------------------------------------------------ CAS-A-NW 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 1 N/A S TER CAS-A-NW 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 1 N/A S TER CAS-A-NW 1 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 1 N/A S TER CAS-A-NW 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 1 N/A S TER CAS-A-NW 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 1 N/A S TER CAS-A-NW 1 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 1 N/A S TER CAS-A-WEST 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 1 N/A S TER CAS-A-WEST 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 2 N/A S TER CAS-A-WEST 2 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 2 N/A S TER CAS-A-WEST 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 2 N/A S TER CAS-A-WEST 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 2 N/A S TER CAS-A-WEST 2 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 2 N/A S TER CAS-A-SW 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 1 none none 2 N/A S TER 15515( 4) - 06-Dec-2018 15:22:54 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ CAS-A-SW 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 2 none none 3 N/A S TER CAS-A-SW 3 WFC3/UVI ACCUM UVIS-CEN F625W 1 3 none none 3 N/A S TER CAS-A-SW 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 1 none none 3 N/A S TER CAS-A-SW 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 2 none none 3 N/A S TER CAS-A-SW 3 WFC3/UVI ACCUM UVIS-CEN F625W 2 3 none none 3 N/A S TER 15515( 4) - 06-Dec-2018 15:22:54 - [ 11] Summary Form for Proposal 15515 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CVZ, ORIENT 131.0D TO 132.0 D, ORIENT 221.0D TO 222.0 D, ORIENT 311.0D TO 312.0 D, ORIENT 41.0D TO 42.0 D, PATTERN 1 1, PATTERN 1 2, PATTERN 1 3, SAME ORIENT AS 01 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F625W ------------------------------------------------------------------------------------------------------------------------------------ Target Names CAS-A-CENTER, CAS-A-EAST, CAS-A-NE, CAS-A-NORTH, CAS-A-NW, CAS-A-SE, CAS-A-SOUTH, CAS-A-SW, CAS-A-WEST ------------------------------------------------------------------------------------------------------------------------------------