10118( 2) - 05/12/04 15:59 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 10118 Version: 2 Check-in Date: 12-May-2004 19:56:00 1.Proposal Title: Imaging the Chemical Distribution in Type Ia SN Ejecta ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle 4. Parallel Pointing Tolerance GO 13 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Dr. Robert A. Fesen Dartmouth College CoI: Dr. Chris L. Gerardy University of Texas at Austin N CoI: Dr. Peter A. Hoeflich University of Texas at Austin N CoI: Dr. Alexei M. Khokhlov Naval Research Laboratory N CoI: Dr. J. Craig Wheeler University of Texas at Austin N CoI: Dr. Andrew J. S. Hamilton University of Colorado at Boulder N ------------------------------------------------------------------------------------ 6. 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 process proceeds from the core outward once it starts. The thermonuclear instability is thought to start off as a subsonic, turbulent deflagration or burning wave but then, at some point, may transition into a blast or detonation wave. In such "delayed detonation" models, 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 results in different final element abundances and internal Fe-rich ejecta structure. Directly imaging the 2-D 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. This 119 year old remnant is visible -- from its core to its outer edge -- via strong optical/UV Ca and Fe line absorptions. Remarkably, the SNR appears to still be in a nearly free expansion phase, meaning that the elemental stratification seen present today accurately reflects SN Ia explosive nucleosynthesis physics. We propose to obtain ACS WFC/HRC images of SN 1885 in order to take advantage of this extraordinary situation: Having a young, nearby Type Ia SN remnant visible in silhouette against a galaxy-size light table. These unique observations will reveal a SN Ia's Ca and Fe ejecta distribution, density structure, sphericity, and ionization state as a function of expansion velocity, thereby confronting various SN Ia models with detailed ejecta stratification and expansion velocity maps. ------------------------------------------------------------------------------------ 10118( 2) - 05/12/04 15:59 - [ 2] Observations Description ------------------------ This program will require ACS ramp filters for WFC and broad UV filters for the ACS/HRC. We have also changed the ramp filter from FR459M to the FR462N as suggested by the review panel. We want to use a dither pattern to remove bad pixels and CRs but limit the movement so that the target, SN 1885, always lies within the desired ramp filter wavelength region - which shouldn't be hard since its only 1 arcsec across. We have used standard dither patterns and sub- patterns and have some concern that the total dither pattern will keep the target (dia. = 1.0 arcsec) within the desired ramp filter bandpass and in a good, clean spot on the ACS/WFC and ACS/HRC. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 10118( 2) - 05/12/04 15:59 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC224- ISM, SNR RA=00H42M42.9S +/- 0.5", J2000 V = 10.0 SN1885 DEC=+41D16'5.0" +/- 0.5" Coordinate Source: HST_IMAGE 10118( 2) - 05/12/04 15:59 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX LINE Pattern_Purpose DITHER DITHER Number_Of_Points 4 2 Point_Spacing 0.171 2.0 Line_Spacing 0.171 Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 30.16 90.0 Angle_Between_Sides 145.82 Center_Pattern NO NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.171 Line_Spacing 0.171 Coordinate_Frame POS-TARG Pattern_Orient 30.16 Angle_Between_Sides 145.82 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type ACS-HRC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.15 Line_Spacing 0.098 Coordinate_Frame POS-TARG Pattern_Orient 19.89 Angle_Between_Sides 63.5 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 10118( 2) - 05/12/04 15:59 - [ 5] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type ACS-HRC-DITHER-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 0.198 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 44.28 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 5 Primary_Pattern Secondary_Pattern Pattern_Type ACS-HRC-DITHER-BOX ACS-HRC-DITHER-LINE Pattern_Purpose DITHER DITHER Number_Of_Points 4 3 Point_Spacing 0.15 0.198 Line_Spacing 0.098 Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 19.89 44.28 Angle_Between_Sides 63.5 Center_Pattern NO NO ------------------------------------------------------------------------------------------------------------------------------------ 10118( 2) - 05/12/04 15:59 - [ 6] Visit: 01 Visit Priority: Visit Requirements: PCS MODE FINE 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 WFC FR462N 4600 1 1130 S PATTERN 2 1 85 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 01 1 1 none none 1 1 565.0 01 1 1 none none 2 1 565.0 01 1 2 none none 1 1 565.0 01 1 2 none none 2 1 565.0 01 1 3 none none 1 2 602.0 01 1 3 none none 2 2 602.0 01 1 4 none none 1 2 602.0 01 1 4 none none 2 2 602.0 10118( 2) - 05/12/04 15:59 - [ 7] Visit: 02 Visit Priority: 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 WFC FR423N 4227 1 1120 S PATTERN 1 1 85 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 02 1 1 1 none 1 1 tbd 02 1 1 1 none 2 1 tbd 02 1 1 2 none 1 1 tbd 02 1 1 2 none 2 1 tbd 02 1 2 1 none 1 2 tbd 02 1 2 1 none 2 2 tbd 02 1 2 2 none 1 2 tbd 02 1 2 2 none 2 2 tbd 02 1 3 1 none 1 3 tbd 02 1 3 1 none 2 3 tbd 02 1 3 2 none 1 3 tbd 02 1 3 2 none 2 3 tbd 02 1 4 1 none 1 4 tbd 02 1 4 1 none 2 4 tbd 02 1 4 2 none 1 4 tbd 02 1 4 2 none 2 4 tbd 10118( 2) - 05/12/04 15:59 - [ 8] Visit: 03 Visit Priority: 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 WFC FR388N 3950 1 1120 S PATTERN 1 1 85 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 03 1 1 1 none 1 1 tbd 03 1 1 1 none 2 1 tbd 03 1 1 2 none 1 1 tbd 03 1 1 2 none 2 1 tbd 03 1 2 1 none 1 2 tbd 03 1 2 1 none 2 2 tbd 03 1 2 2 none 1 2 tbd 03 1 2 2 none 2 2 tbd 03 1 3 1 none 1 3 tbd 03 1 3 1 none 2 3 tbd 03 1 3 2 none 1 3 tbd 03 1 3 2 none 2 3 tbd 03 1 4 1 none 1 4 tbd 03 1 4 1 none 2 4 tbd 03 1 4 2 none 1 4 tbd 03 1 4 2 none 2 4 tbd 10118( 2) - 05/12/04 15:59 - [ 9] Visit: 04 Visit Priority: 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/HRC ACCUM HRC F330W 1 1300 S PATTERN 3 1 85 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC224-SN18 ACS/HRC ACCUM HRC F330W 1 1300 S PATTERN 4 2 85 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 04 1 1 none none 1 1 tbd 04 1 1 none none 2 1 tbd 04 1 2 none none 1 1 tbd 04 1 2 none none 2 1 tbd 04 1 3 none none 1 2 tbd 04 1 3 none none 2 2 tbd 04 1 4 none none 1 2 tbd 04 1 4 none none 2 2 tbd 04 2 1 none none 1 3 tbd 04 2 1 none none 2 3 tbd 04 2 2 none none 1 3 tbd 04 2 2 none none 2 3 tbd 10118( 2) - 05/12/04 15:59 - [ 10] Visit: 05 Visit Priority: 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/HRC ACCUM HRC F250W 1 1300 S PATTERN 5 1 85 ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Visit Id| Exp Id |Primary |Secondary |Iteration |CR-SPLIT |Orbit Num |Duration | |Pattern Pos |Pattern Pos |Num |Num | | ------------------------------------------------------------------------------------------------------------------------------------ 05 1 1 1 none 1 1 tbd 05 1 1 1 none 2 1 tbd 05 1 1 2 none 1 1 tbd 05 1 1 2 none 2 1 tbd 05 1 1 3 none 1 2 tbd 05 1 1 3 none 2 2 tbd 05 1 2 1 none 1 2 tbd 05 1 2 1 none 2 2 tbd 05 1 2 2 none 1 3 tbd 05 1 2 2 none 2 3 tbd 05 1 2 3 none 1 3 tbd 05 1 2 3 none 2 3 tbd 05 1 3 1 none 1 4 tbd 05 1 3 1 none 2 4 tbd 05 1 3 2 none 1 4 tbd 05 1 3 2 none 2 4 tbd 05 1 3 3 none 1 5 tbd 05 1 3 3 none 2 5 tbd 05 1 4 1 none 1 5 tbd 05 1 4 1 none 2 5 tbd 05 1 4 2 none 1 6 tbd 05 1 4 2 none 2 6 tbd 05 1 4 3 none 1 6 tbd 05 1 4 3 none 2 6 tbd 10118( 2) - 05/12/04 15:59 - [ 11] Summary Form for Proposal 10118 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC HRC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ACS/HRC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PCS MODE FINE PATTERN 2 1 PATTERN 1 1 PATTERN 3 1 PATTERN 4 2 PATTERN 5 1 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements FR462N FR423N FR388N F330W F250W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC224-SN1885 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 4600 4227 3950 ------------------------------------------------------------------------------------------------------------------------------------