! Proposal 6435, submission 6 ! PI: Robert Fesen ! Received Thu Apr 18 16:27:45 EDT 1996 ! From: fesen@snr.dartmouth.edu ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6435,v 14.1 1997/04/10 20:13:01 pepsa Exp $ ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! $Id: 6435,v 14.1 1997/04/10 20:13:01 pepsa Exp $ ! ! Refer to the HST Phase II Proposal Instructions to fill this out ! ! Anything after a "!" is ignored, and may be deleted ! ! All keywords with multiple entries are comma delimited except the ! Visit_Requirements and Special_Requirements keywords which can be ! delimited with carriage returns or semi-colons, but not commas ! ! For help call your Program Coordinator: Ready ! Phone: 410-338-4546 , E-mail: ready@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Name of Phase I Proposal: archive-0122.fesen.prop ! Date generated: Fri Dec 22 17:34:07 EST 1995 ! Proposal_Information ! Section 4 Title: A WFPC2 Search for Surviving Binary Companions in SN Ia Remnants Proposal_Category: GO Scientific_Category: INTERSTELLAR MEDIUM Cycle: 6 Investigators PI_name: Robert Fesen PI_Institution: Dartmouth College CoI_Name: John Thorstensen CoI_Institution: Dartmouth College Contact: ! Y or N (designate at most one contact) CoI_Name: Alan Hurford CoI_Institution: Dartmouth College Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) 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. Questions ! Free format text (please update) Observing_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: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number:1 Target_Name:TYCHO-SNR Alternate_Names:SN1572 Description:ISM Position:RA=0H 25M 17.50S +/-0.50S,DEC=64D 8' 12.0" +/-5.0" ! Most common specification format is ! RA=0H 0M 0.00S +/- 0S, ! DEC=0D 0' 0.0" +/- 0", ! PLATE-ID=0000 Equinox:2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux:V=25.0 +/-2.0 ! Include at least V and B-V Comments: E(B-V)=0.66 +/-0.05 Target_Number:2 Target_Name:SN1006-CENTER Alternate_Names:G327.6+14.6 Description:ISM Position:RA=15H 2M 53.0S +/-0.50S,DEC=-41D 55' 45.0" +/-10.0" ! Most Equinox:2000 RV_or_Z: RA_PM: ! Units are seconds of time per year Dec_PM: ! Units are seconds of arc per year Epoch: Annual_Parallax: Flux:V=25.0 +/-2.0 ! Include at least V and B-V Comments:E(B-V)=0.11 +/-0.02 ! This is a template for a single visit containing a single exposure ! Repeat exposure and visit blocks as needed Visits ! Section 6 Visit_Number:1 Visit_Requirements:CVZ ! Section 7.1 ! Uncomment or copy visit level special requirements needed ! Most of these requirements (including ORIENT) will limit scheduling ! PCS MODE [Fine | Gyro] ! GUIDing TOLerance ! DROP TO GYRO IF NECESSARY [NO REACQuisition] ! ORIENTation TO ! ORIENTation TO FROM ! ORIENTation TO FROM NOMINAL ! SAME ORIENTation AS ! CVZ ! PARallel ! SCHEDulability ! AFTER [BY [TO ]] ! AFTER ! BEFORE ! BETWEEN AND ! GROUP WITHIN