14733( 3) - 07-Jul-2016 14:34:20 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14733 Version: 3 Check-in Time: 07-Jul-2016 14:34:20 STScI Edit Number: 0 Title Single-Degenerate or Double-Degenerate? The Case for a Third Epoch Observation of the Confirmed Ia Supernova Remnant 0509-67.5 ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Luke Hovey Los Alamos National Laboratory Y CoI: Dr. John P. Hughes Rutgers the State University of New Jersey N CoI: Dr. Kristoffer A. Eriksen Los Alamos National Laboratory N ------------------------------------------------------------------------------------ Abstract Observations of Ia supernovae have been invaluable in measuring distances on cosmological scales and led to the discovery of the accelerating universe. Even though it is accepted that these supernovae are the result of thermonuclear explosions of accreting white dwarf stars, little is known on the progenitor systems. One important tool in constraining these systems is the observations of supernova remnants. The remnant 0509-67.5 is of particular interest in this endeavor due to its remarkably circular structure and being situated in the Large Magellanic Cloud (LMC). Being located in the LMC, we know the distance to this remnant to greater accuracy than any of the galactic remnants. This enables us to translate the proper motion measurements of the forward shock into physical units of velocity, which we have done in Hovey et al. (2015). Using these measurements we are able to assess a dynamical offset of the explosion site from the geometric center of the remnant in the east-west plane. Unfortunately we are unable to make this measurement in the north-south plane due to our second epoch observation being imaged with the WFPC2 camera after the ACS camera failed. We are requesting a third observation of 0509-67.5 with the ACS camera so we can fully constrain the search radius for a possible surviving companion star. With a third epoch observation, we will be able to measure the proper motions around the entire rim to with much higher precision than those in Hovey et al. (2015) and place the best constraint on possible progenitor companion. This measurement is not technically challenging, but will deepen our knowledge of the progenitor systems of Ia supernovae. ------------------------------------------------------------------------------------ Observations Description ------------------------ We have been awarded two orbits of HST time to obtain a third epoch observation of the LMC supernova remnant 0509-67.5 in order to measure the proper motions of the forward shock where the S/N was too low in our second epoch WFPC2 observation. Hence, we ask for a standard 4-point box dither pattern with the ACS WFC camera using a F658N narrow-band filter. This data will be used to constrain the search area for surviving companion stars under the single-degenerate model of Ia supernovae. ------------------------------------------------------------------------------------ 14733( 3) - 07-Jul-2016 14:34:20 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SNR0509-67.5 ISM, SNR RA=05H09M31.2000S, J2000 V = 18 +/- .5 DEC=-67D31'16.70" Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 14733( 3) - 07-Jul-2016 14:34:20 - [ 3] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.265 Line_Spacing 0.187 Coordinate_Frame POS-TARG Pattern_Orient 20.67 Angle_Between_Sides 69.05 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 14733( 3) - 07-Jul-2016 14:34:20 - [ 4] Visit: 01 Visit Requirements: ORIENT 321.2D TO 342.2 D On Hold Comments: Additional Comments: We ask that this be on WFC-2 and the roll angle be as close to -28.7994 degrees (or 331.2006) as possible (determined from taking the PA_APER keyword of -31.2714 from the 2006 ACS WFC observation of 0509-67.5, then subtracting $\beta_y$ of 177.528 for the WFC and then adding 180 degrees, as per the instructions found here: http://www.stsci.edu/hst/acs/documents/handbooks/cycle19/c07_obstechniques09.html in section 7.8.1) so that the PSFs of the image is nearly identical of the ACS observation taken in 2006 ID#11015 so that proper motions can be measured in low S/N portions of the remnant's rim. 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 SNR0509-67. ACS/WFC ACCUM WFC2 F658N CR-SPLIT=2 1 1333 S PATTERN 1 1 5 see below (5331 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 | ------------------------------------------------------------------------------------------------------------------------------------ SNR0509-67.5 1 ACS/WFC ACCUM WFC2 F658N 1 none none 1 1 642.0 S SNR0509-67.5 1 ACS/WFC ACCUM WFC2 F658N 1 none none 2 1 642.0 S SNR0509-67.5 1 ACS/WFC ACCUM WFC2 F658N 2 none none 1 1 642.0 S SNR0509-67.5 1 ACS/WFC ACCUM WFC2 F658N 2 none none 2 1 643.0 S SNR0509-67.5 1 ACS/WFC ACCUM WFC2 F658N 3 none none 1 2 690.0 S SNR0509-67.5 1 ACS/WFC ACCUM WFC2 F658N 3 none none 2 2 690.0 S SNR0509-67.5 1 ACS/WFC ACCUM WFC2 F658N 4 none none 1 2 691.0 S SNR0509-67.5 1 ACS/WFC ACCUM WFC2 F658N 4 none none 2 2 691.0 S 14733( 3) - 07-Jul-2016 14:34:20 - [ 5] Summary Form for Proposal 14733 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC2 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=2 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 321.2D TO 342.2 D, PATTERN 1 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F658N ------------------------------------------------------------------------------------------------------------------------------------ Target Names SNR0509-67.5 ------------------------------------------------------------------------------------------------------------------------------------