6435( 14) - 04/18/97 13:18 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6435 Version: 14 Check-in Date: 10-Apr-1997 16:13:04 1.Proposal Title: A WFPC2 Search for Surviving Binary Companions in SN Ia Remnants ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle INTERSTELLAR MEDIUM GO 6 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: ROBERT A. FESEN Dartmouth College CoI: John Thorstensen Dartmouth College N CoI: Alan Hurford Dartmouth College N ------------------------------------------------------------------------------------ 6. Abstract Type Ia supernovae (SNe Ia) are widely believed to be explosions of white dwarfs undergoing binary mass accretion. Determining the type of interacting binary system leading to SNe Ia is an important yet unsolved astrophysical problem, encompassing binary star evolution, mass accretion rates, and thermonuclear physics. Identifying the correct binary model(s) for SNe Ia is unlikely to be accomplished by theory alone, and extragalactic SNe observations can provide only limited model constraints. Because 2-D hydrodynamic studies indicate that symbiotic and cataclysmic SN binaries should leave surviving companion stars, we propose a more direct approach: a deep search for surviving SN Ia companions. , , We will use the WFPC2 to identify SN Ia surviving companions or set strong empirical limits on post- SN kinematic and luminosity properties of surviving companions, in order to determine likely SN Ia progenitor systems. UVBRI images would be taken of two galactic SN Ia remnants, Tycho's SNR (SN 1572) & SN 1006. The stellar population near the geometric centers of each (search radii: Tycho = 15''; SN 1006 = 40'') will be examined to M_ V = +12 (Tycho) and +14.7 (SN 1006) via 10 to 30 minute WF camera images. Relative astrometry from Cycle 7 & 8 images will identify high proper motions survivor candidates (v_ transverse >= 150 km s^-1) compatible with the remnant's age and expansion center location. ------------------------------------------------------------------------------------ 6435( 14) - 04/18/97 13:18 - [ 2] Observations Description ------------------------ TYCHO's SNR: At Dec 63^degrees and an RA = 6.25^degrees, Tycho lies in the CVZ (96 min orbit) with a maximum of ~eq 90 orbits in any single CVZ interval, and 4 CVZ opportunities per year (pgs 52, 56; Phase I Proposal Instructions book). Following a 15 min initial ACQ, we would take short UBVRI exposure frames (2 to 30 sec), helpful for measuring accurate colors for close pairs of bright (~eq 15 mag) and faint stars (~eq 21 mag). With a 2 min readout overhead and 1 min for filter change, this totals 20 min. For deep V, R, I filter imaging, we would take four ten minute exposures to detect down to m(V) = 26.2 with good rejection of cosmic rays and bad pixels. These exposures total 4 * (10 min exp. + 2 min readout + 1 min for dithered positioning) = 52 min per filter, and 156 min in total. Because the U and B filters require longer exposures (lower WFPC2 QE), we will take three 25 min B exposures and three 33 min U exposures: thus, 3 * (1500 s B filter exp. + 2 min readout) = 81 min, and 3 * (2000 s U filter exp. + 2 min readout) = 106 min. The Grand Total for all exposures is 378 minutes. This can be done during four CVZ orbits (4 x 96 min = 384 min). All imaging would use the recommended UBVRI filter set, ie. filters F336W, F439W, F555W, F675W, F814W. Using the on-line WFPC2 exposure calculator, 600 sec V, R, I images will detect stars of spectral types G0 thru M0 down to m = 26.0 with a S/N of 5 or better. For a hot, reddened (E(B--V) = 0.66) source, like a remnant RG core, a 1500 sec B image will detect m = 23.4 (B0 like spectrum; S/N=5) and an 2000 sec U filter will detect m = 23.0 mag (B0; S/N=5). The WFC's 80'' FOV will cover velocities up to 950 km s^-1 (d/2.5 kpc). SN 1006: With a 54 min visibility each orbit (Table 2: Proposal Inst. Book), we would use the first orbit with the longer (15 min) ACQ time to obtain short WFC exposures in each filter, 30 min total. Five orbits are then needed to image the prime 40'' search radius (V_ T <= 250 km s^-1), meaning one orbit per UBVRI filter. This requires 3 * (700 sec exposures + 2 min readout + 1 min dither) = 44 min + 7 min ACQ = 51 min (during each 54 min orbit). Two (2) additional orbits will image adjacent regions (40'' to the NE and SW) for detection of higher velocity candidates (up to 600 km s^-1 (d/1.7 kpc)) using the R filter (F675W) down to m = 26.9 using 700 s exposures. Grand Total: 8 orbits. Cycles 7 and 8: Tycho's SNR: 1 Orbit (CVZ = 96 min) to obtain R-band image of expansion center for relative astrometry. SN 1006: 3 orbits (54 min) to take 3 sets of R-band astrometry images covering entire companion search region. Total: 4 orbits each cycle. Real Time Justification ----------------------- NONE We will obtain UBVRI observations of the entire Tycho SNR using the MDM 2.4m and WFPC2 matching filters to provide supporting data on the region's stellar population. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6435( 14) - 04/18/97 13:18 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: UPS Email: ------------------------------------------------------------------------------------ 6435( 14) - 04/18/97 13:18 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 TYCHO-SNR ISM RA=0H 25M 17.50S +/- 2000 V = 25.0+/-2.0 0.50S,DEC=64D 8' 12.0" +/-5.0" Comments: E(B-V)=0.66 +/-0.05 2 SN1006- ISM RA=15H 2M 53.0S +/-0.50S,DEC=- 2000 V = 25.0+/-2.0 CENTER 41D 55' 45.0" +/-10.0" Comments: E(B-V)=0.11 +/-0.02 6435( 14) - 04/18/97 13:18 - [ 5] Visit: 01 Visit Requirements: CVZ On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 110 TYCHO-SNR WFPC2 IMAGE WF3-FIX F814W 1 10 S ------------------------------------------------------------------------------------------------------------------------------------ 111 TYCHO-SNR WFPC2 IMAGE WF3-FIX F814W CR-SPLIT=NO 2 500 S ------------------------------------------------------------------------------------------------------------------------------------ 112 TYCHO-SNR WFPC2 IMAGE WF3-FIX F814W CR-SPLIT=NO 2 500 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 120 TYCHO-SNR WFPC2 IMAGE WF3-FIX F675W 1 10 S ------------------------------------------------------------------------------------------------------------------------------------ 121 TYCHO-SNR WFPC2 IMAGE WF3-FIX F675W CR-SPLIT=NO 2 900 S ------------------------------------------------------------------------------------------------------------------------------------ 122 TYCHO-SNR WFPC2 IMAGE WF3-FIX F675W CR-SPLIT=NO 2 900 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 130 TYCHO-SNR WFPC2 IMAGE WF3-FIX F555W 1 10 S ------------------------------------------------------------------------------------------------------------------------------------ 131 TYCHO-SNR WFPC2 IMAGE WF3-FIX F555W CR-SPLIT=NO 2 700 S ------------------------------------------------------------------------------------------------------------------------------------ 132 TYCHO-SNR WFPC2 IMAGE WF3-FIX F555W CR-SPLIT=NO 2 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 140 TYCHO-SNR WFPC2 IMAGE WF3-FIX F439W 1 20 S ------------------------------------------------------------------------------------------------------------------------------------ 141 TYCHO-SNR WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 2 700 S ------------------------------------------------------------------------------------------------------------------------------------ 142 TYCHO-SNR WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 2 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 150 TYCHO-SNR WFPC2 IMAGE WF3-FIX F336W CR-SPLIT=NO 1 20 S ------------------------------------------------------------------------------------------------------------------------------------ 151 TYCHO-SNR WFPC2 IMAGE WF3-FIX F336W CR-SPLIT=NO 2 700 S ------------------------------------------------------------------------------------------------------------------------------------ 152 TYCHO-SNR WFPC2 IMAGE WF3-FIX F336W CR-SPLIT=NO 2 700 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 171 TYCHO-SNR WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 2 500 S ------------------------------------------------------------------------------------------------------------------------------------ 172 TYCHO-SNR WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 2 500 S POS TARG 0.25, 0.25 ------------------------------------------------------------------------------------------------------------------------------------ 6435( 14) - 04/18/97 13:18 - [ 6] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 211 SN1006-CENT WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 2 400 S ER ------------------------------------------------------------------------------------------------------------------------------------ 212 SN1006-CENT WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 2 400 S POS TARG 0.25, 0.25 ER ------------------------------------------------------------------------------------------------------------------------------------ 221 SN1006-CENT WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 500 S ER ------------------------------------------------------------------------------------------------------------------------------------ 222 SN1006-CENT WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 500 S POS TARG 0.25,0.25 ER ------------------------------------------------------------------------------------------------------------------------------------ 231 SN1006-CENT WFPC2 IMAGE PC1-FIX F439W CR-SPLIT=NO 2 500 S ER ------------------------------------------------------------------------------------------------------------------------------------ 232 SN1006-CENT WFPC2 IMAGE PC1-FIX F439W CR-SPLIT=NO 2 500 S POS TARG 0.25, 0.25 ER ------------------------------------------------------------------------------------------------------------------------------------ 241 SN1006-CENT WFPC2 IMAGE PC1-FIX F336W CR-SPLIT=NO 2 500 S ER ------------------------------------------------------------------------------------------------------------------------------------ 242 SN1006-CENT WFPC2 IMAGE PC1-FIX F336W CR-SPLIT=NO 2 500 S POS TARG 0.25,0.25 ER ------------------------------------------------------------------------------------------------------------------------------------ 6435( 14) - 04/18/97 13:18 - [ 7] Visit: 03 Visit Requirements: ORIENT 179D TO 181D FROM 2 On Hold Comments: Additional Comments: WANT VISIT 3 IMAGES TO BE ROTATED NEARLY 180D FROM THOSE OF VISIT 2. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 311 SN1006-CENT WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 2 400 S ER ------------------------------------------------------------------------------------------------------------------------------------ 312 SN1006-CENT WFPC2 IMAGE PC1-FIX F675W CR-SPLIT=NO 2 400 S POS TARG 0.25, 0.25 ER ------------------------------------------------------------------------------------------------------------------------------------ 321 SN1006-CENT WFPC2 IMAGE PC1-FIX F439W CR-SPLIT=NO 2 500 S ER ------------------------------------------------------------------------------------------------------------------------------------ 322 SN1006-CENT WFPC2 IMAGE PC1-FIX F439W CR-SPLIT=NO 2 500 S POS TARG 0.25, 0.25 ER ------------------------------------------------------------------------------------------------------------------------------------ 331 SN1006-CENT WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 500 S ER ------------------------------------------------------------------------------------------------------------------------------------ 332 SN1006-CENT WFPC2 IMAGE PC1-FIX F555W CR-SPLIT=NO 2 500 S POS TARG 0.25, 0.25 ER ------------------------------------------------------------------------------------------------------------------------------------ 341 SN1006-CENT WFPC2 IMAGE PC1-FIX F336W CR-SPLIT=NO 2 500 S ER ------------------------------------------------------------------------------------------------------------------------------------ 342 SN1006-CENT WFPC2 IMAGE PC1-FIX F336W CR-SPLIT=NO 2 500 S POS TARG 0.25, 0.25 ER ------------------------------------------------------------------------------------------------------------------------------------ 6435( 14) - 04/18/97 13:18 - [ 8] Summary Form for Proposal 6435 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category INTERSTELLAR MEDIUM ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CVZ POS TARG 0.25, 0.25 POS TARG 0.25,0.25 ORIENT 179D TO 181D FROM 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F814W F675W F555W F439W F336W ------------------------------------------------------------------------------------------------------------------------------------ Target Names TYCHO-SNR SN1006-CENTER ------------------------------------------------------------------------------------------------------------------------------------