11722( 2) - 26-Jun-2008 15:27:38 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11722 Version: 2 Check-in Time: 26-Jun-2008 15:27:38 STScI Edit Number: 0 Title Imaging the Distribution of Iron in a Type Ia Supernova ------------------------------------------------------------------------------------ Type Cycle GO 17 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Robert A. Fesen Dartmouth College CoI: Dr. Andrew J. S. Hamilton University of Colorado at Boulder N CoI: Dr. Peter A. Hoeflich Florida State University N CoI: Dr. Chris L. Gerardy Florida State University N ------------------------------------------------------------------------------------ Abstract We know Type Ia supernovae are thermonuclear explosions of CO white dwarfs, but we don't know the specifics of how the nuclear burning proceeds from the core outward to the surface once it starts. Thermonuclear instability in a WD core is thought to start off as a subsonic, turbulent deflagration wave or "burning" wave but then may, at some point, transition into a supernova blast or detonation wave. In such a "delayed detonation" model, differences between normal and subluminous Type Ia SNe reflect differences in the amount of burning that has occurred in the pre-detonation phase. More burning helps to pre-expand the WD before passage of the detontation wave which then lowers the density of the outer layers and, in turn, results in a different element production and internal structure. Directly imaging the 2D chemical distribution of ejecta from a Type Ia SN is actually possible in the case of the subluminous Type Ia SN 1885 which occurred on the near-side of M31's central bulge. The entire 123 year old remnant -- core to outer edge -- is visible via strong near-UV, Ca and Fe line absorptions, and remarkably, is still in near free expansion. This means that elemental stratification seen today is likely to accurately reflect the explosive nucleosynthesis physics. We propose ACS WFC images of SN 1885 to take advantage of this extraordinary situation: Having a young, nearby Type Ia SN remnant visible in silhouette against a galaxy-size light table. The proposed observations will reveal the Fe ejecta distribution, density structure, sphericity, and ionization state as a function of expansion velocity, thereby testing SN Ia explosion models with direct Fe-rich ejecta mapping data. ------------------------------------------------------------------------------------ Observations Description ------------------------ This project is to image the remnant of SN 1885A in the bulge of M31 using the ramp filter FR388N centered on the remnant at the wavelength of 3710 Angstroms. All five orbits will be used to image the target in this filter. The target (SNR 1885A) is only 0.8 arcsec across (diameter). Real Time Justification 11722( 2) - 26-Jun-2008 15:27:38 - [ 2] ----------------------- none. Calibration Justification ------------------------- none. Additional Comments ------------------- ------------------------------------------------------------------------------------ 11722( 2) - 26-Jun-2008 15:27:38 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC224-SN188 ISM, SNR, EJECTA RA=00H42M42.9000S +/- 0.1", J2000 V = 10.0 +/- 1.0 5 DEC=+41D16'5.00" +/- 0.1" Reference Frame: ICRS Comments: ------------------------------------------------------------------------------------------------------------------------------------ 11722( 2) - 26-Jun-2008 15:27:38 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-LINE ACS-WFC-DITHER-LINE Pattern_Purpose DITHER DITHER Number_Of_Points 5 2 Point_Spacing 0.149 0.29 Line_Spacing Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 34.25 47.23 Angle_Between_Sides Center_Pattern NO NO ------------------------------------------------------------------------------------------------------------------------------------ 11722( 2) - 26-Jun-2008 15:27:38 - [ 5] Visit: 01 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC224-SN18 ACS/WFC ACCUM WFC2-MRAM FR388N 3720.0 2 550.0 S PATTERN 2 1 85 P see below ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 1 1 1 none 1 591.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 1 1 2 none 1 591.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 1 2 1 none 1 591.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 1 2 2 none 1 591.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 2 1 1 none 2 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 2 1 2 none 2 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 2 2 1 none 2 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 2 2 2 none 2 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 3 1 1 none 3 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 3 1 2 none 3 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 3 2 1 none 3 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 3 2 2 none 3 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 4 1 1 none 4 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 4 1 2 none 4 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 4 2 1 none 4 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 4 2 2 none 4 646.0 S MP 0 11722( 2) - 26-Jun-2008 15:27:38 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 5 1 1 none 5 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 5 1 2 none 5 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 5 2 1 none 5 646.0 S MP 0 NGC224-SN1885 1 ACS/WFC ACCUM WFC2-MRA FR388N 3720. 5 2 2 none 5 646.0 S MP 0 11722( 2) - 26-Jun-2008 15:27:38 - [ 7] Summary Form for Proposal 11722 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC2-MRAMP ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 2 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements FR388N ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC224-SN1885 ------------------------------------------------------------------------------------------------------------------------------------