6052( 17) - 03/21/96 15:46 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6052 Version: 17 Check-in Date: 21-Mar-1996 15:43:51 1.Proposal Title: Excitation Mechanisms and Abundances in the O-rich SNR E0102.2--7219 in the SMC ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Interstellar Medium GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Jon A. Morse Space Telescope Science Institute CoI: Michael A. Dopita Mt. Stromlo & Siding Spring Obs. N CoI: William P. Blair Johns Hopkins University N CoI: John C. Raymond Harvard-Smithsonian CfA N CoI: John P. Hughes Harvard-Smithsonian CfA N CoI: Robert P. Kirshner Harvard University N CoI: Knox S. Long Space Telscope Science Institute N CoI: Ralph Sutherland Univ. of Colorado -- Boulder / JILA N CoI: P. Frank Winkler Middlebury College N ------------------------------------------------------------------------------------ 6. Abstract We propose to obtain WFPC2 images and FOS spectra of the young, oxygen-rich supernova remnant E0102.2--7219 in the Small Magellanic Cloud. The images will be used to study the fine-scale spatial and ionization structures within the knotty filaments, and also provide EARLY ACQ exposures for the spectroscopy. The FOS spectra will provide relative intensities of UV and optical emission lines in isolated knots. Only HST has the resolving power necessary to study individual knots in the remnant. We will compare the observed line ratios to predictions made by theoretical models in order to determine the excitation mechanisms and to derive reliable elemental abundances. E0102.2--7219 is one of only two O-rich supernova remnants that can be studied effectively at UV wavelengths, and the HST data will provide important tests for theories of nucleosynthesis in massive stars as well as improve our understanding of the dynamics of supernova explosions and mixing in the ejecta. We will compare these data to our HST Cycle 4 observations of N132D in the LMC to investigate differences between these SNRs apparent in the IUE spectra. ------------------------------------------------------------------------------------ 6052( 17) - 03/21/96 15:46 - [ 2] Observations Description ------------------------ WFPC2 Imaging: We request WFPC2 F502N (O IIILambda5007), F375N (O IILambda3727) and F547M (continuum) exposures of E0102 with the Wide Field Camera (WFC) to study small scale spatial and ionization structure in the O-rich filaments. Achieving 0.''1 resolution in E0102 will resolve structure similar to a 2'' ground-based image of Cas A, sufficient to identify excitation variations in individual filaments. The WFPC2 images will also be used as EARLY ACQ exposures to verify that the filaments selected for spectroscopy are appropriate and to set up the FOS blind offset acquisitions. The total velocity range in E0102 is larger than the F502N and F375N filter widths, so we will concentrate on those filaments in the SE rim (see Fig. 1) that the velocity maps of Tuohy & Dopita (1983) show will be included in the bandpasses. The SE rim is also where we placed the IUE aperture. To estimate the expected count rates, we used the formula N_el = 2.28 * 10^12,Lambda T_max F, where N_el is the number of electrons detected per second, T_max is the throughput at the wavelength Lambda (in Angstrom) from the WFPC2 handbook, and F is the observed integrated line flux (in ergs cm^-2 s^-1) per unit area on the sky being considered. Table 2 gives N_el per 0.''1 WFC pixel using the fluxes of Blair Etal\\ (1989) and assuming an enhancement of the count rate in the filaments by a factor of 3 due to the clumpiness of the emission. centerline figure=tab2.ps,height=1.9in,width= A 1000 s continuum image through the broader F547M filter will be sufficient to distinguish stars from ``stellar-appearing" emission knots. We thus request a total of 6 orbits (including acquisition and instrument overheads) for the WFPC2 imaging: 1.5 orbits for F502N, 0.5 orbits for F547M, and 4 orbits for F375N. FOS Spectroscopy: The large body of optical and IUE data for E0102 that we have published can be used to estimate the feasibility of HST observations. The UV/optical line fluxes listed in Blair Etal\\ (1989) are integrated over roughly a 100 arcsec^2 region in the SE rim of E0102. We will obtain spectra at two positions in the SE rim since our optical spectra show that significant variations in the excitation exist over scales sampled by the large IUE aperture (Dopita & Tuohy 1984). Although the total velocity range in E0102 is large, the velocity dispersion within individual knots is small enough that the total flux from each emission line will fall within ~ 1 diode. Table 3 lists emission-line flux estimates for observations made through the FOS 0.''9 circular aperture. Using the formula for monochromatic fluxes from Table 1.2.1 of the Version 5.0 FOS handbook and the integration times shown, one obtains the total counts per diode listed in the last column. These are conservative estimates because the peak surface brightness in individual knots will be several times higher than the average over the IUE aperture that the fluxes listed represent. Note that the O I (Lambda1356/Lambda7774) line ratio has a theoretical value of 5.9, and will provide an excellent baseline for reddening corrections. centerline figure=tab3.ps,height=4.5in,width= From the WFPC2 EARLY ACQ images, we will use Binary Search mode for acquiring an offset star and then perform blind offsets to the two knot positions. Each position will require 6 orbits (including acquisition and instrument overheads) for a total FOS program of 12 orbits. Real Time Justification ----------------------- We have computed the required number of orbits for our observing program assuming the normal visibility of 59 minutes per orbit. However, there are two CVZ opportunities for the RA and Dec of our target during Cycle 5, though totaling only ~ 50 hours. Assuming two windows of 25 hours each (~ 16 CVZ orbits) separated by several months, we could accomplish our WFPC2 imaging during the first CVZ opportunity and our FOS spectroscopy during the second. With the ~ 50\\ increased viewing time, our WFPC2 images could be obtained in 4 CVZ orbits and our FOS spectra in 8 CVZ orbits, for a total of 12 CVZ orbits instead of 18 normal viewing orbits. We have worked hard with IUE to obtain the existing UV data on E0102. The spectra shown in Fig. 3 involved lengthy double -shift IUE exposures, but IUE simply cannot resolve individual filaments. Hence, blending of material with different physical conditions and abundances hampers an accurate comparison with models. We have optical observations (CCD images in a number of optical lines, and spectra) as well as the most recent ROSAT and ASCA data. Collectively, these data will provide important additional support for and comparison with the HST data. Calibration Justification ------------------------- Additional Comments ------------------- Please ensure that WFPC-2 EARLY/ACQ imaging is scheduled well in advance of FOS spectroscopy. ------------------------------------------------------------------------------------ 6052( 17) - 03/21/96 15:46 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: Dr. Jon Morse*CASA*University of Colorado*Campus Box 389*Boulder, CO 80309 Ship Via: UPS Email: , ------------------------------------------------------------------------------------ 6052( 17) - 03/21/96 15:46 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 E0102-7219 ISM, SNR RA=01H04M01.50S +/- 0.1S, DEC=- 2000 V=+200 SURF(V) = 25.3+/-1 72D01'55.7" +/- 1", PLATE- SURF-LINE(5007)=3+/-1e-15 ID=015Q 2 E0102-OFFSET STAR RA=01H04M00.96S +/- 0.05S, DEC=- 2000 V = 18.35+/-0.2 72D01'57.2" +/- 0.3" Comments: WFPC2 coords using METRIC, V_mag from F547M exposure. 3 E0102-POS1 ISM, SNR, KNOT R=6.31", PA=175.32D, FROM 2 2000 V=+200 SURF(V) = 25.3+/-1 SURF-LINE(5007)=3+/-1e-15 Comments: Knot selection from WFPC2 F502N image. 6052( 17) - 03/21/96 15:46 - [ 5] Visit: 01 Visit Requirements: ORIENT 150D TO 240D On Hold Comments: <none> Additional Comments: EARLY ACQ images to identify target for FOS spectroscopy. Best ORIENT is 210D. Try to schedule as early as possible. Put target in middle of PC1 and orient so that at WF chips cover regions N and E of target. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 E0102-7219 WFPC2 IMAGE PC1-FIX F547M 1 900S ------------------------------------------------------------------------------------------------------------------------------------ 2 E0102-7219 WFPC2 IMAGE PC1-FIX F502N CR-SPLIT=NO 1 1400S EXPAND ------------------------------------------------------------------------------------------------------------------------------------ 3 E0102-7219 WFPC2 IMAGE PC1-FIX F502N 1 2800S ------------------------------------------------------------------------------------------------------------------------------------ 4 E0102-7219 WFPC2 IMAGE PC1-FIX F502N 1 2800S ------------------------------------------------------------------------------------------------------------------------------------ 6052( 17) - 03/21/96 15:46 - [ 6] Visit: 02 Visit Requirements: <none> On Hold Comments: <none> Additional Comments: Acquire offset star with 2x6 ACQ/PEAK (1.0), then ACQ/BIN (4.3) and ACQ/PEAK (0.3), offset to SNR knot, and run through exposures. Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 101 E0102- FOS/RD ACQ/PEA 4.3 MIRROR SEARCH-SIZE- 1 15S ONBOARD ACQ FOR 102 OFFSET K X=2,SEARCH-SIZE -Y=6,SCAN-STEP- X=3.3,SCAN-STEP -Y=1.23 ------------------------------------------------------------------------------------------------------------------------------------ 102 E0102- FOS/RD ACQ/BIN 4.3 MIRROR FAINT=330 1 100S ONBOARD ACQ FOR 103 OFFSET ARY ------------------------------------------------------------------------------------------------------------------------------------ 103 E0102- FOS/RD ACQ/PEA 0.25- MIRROR SEARCH-SIZE- 1 25S ONBOARD ACQ FOR 104-108 OFFSET K PAIR-A X=4,SEARCH-SIZE -Y=4,SCAN-STEP- X=.172,SCAN- STEP-Y=.172 ------------------------------------------------------------------------------------------------------------------------------------ 104 E0102-POS1 FOS/RD ACCUM 1.0- G780H STEP- 1 2400S NO SPLIT PAIR-A PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 105 E0102-POS1 FOS/RD ACCUM 1.0- G570H STEP- 1 1200S NO SPLIT PAIR-A PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 106 E0102-POS1 FOS/RD ACCUM 1.0- G400H STEP- 1 1250S NO SPLIT PAIR-A PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 107 E0102-POS1 FOS/RD ACCUM 1.0- G270H STEP- 1 2600S NO SPLIT PAIR-A PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 108 E0102-POS1 FOS/BL ACCUM 1.0- G160L STEP- 1 7600S PAIR-A PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ 6052( 17) - 03/21/96 15:46 - [ 7] Summary Form for Proposal 6052 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 FOS/RD FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ACQ/PEAK ACQ/BINARY ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO SCAN-STEP-Y=1.23 FAINT=330 SCAN-STEP-Y=.172 STEP-PATT=SINGLE ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Interstellar Medium ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 150D TO 240D EXPAND ONBOARD ACQ FOR 102 ONBOARD ACQ FOR 103 ONBOARD ACQ FOR 104-108 NO SPLIT ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F547M F502N MIRROR G780H G570H G400H G270H G160L ------------------------------------------------------------------------------------------------------------------------------------ Target Names E0102-7219 E0102-OFFSET E0102-POS1 ------------------------------------------------------------------------------------------------------------------------------------