6031( 10) - 09/20/95 11:21 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 6031 Version: 10 Check-in Date: ********** 1.Proposal Title: UV SPECTROSCOPY OF TWO VERY C-POOR HALO PLANETARY NEBULAE ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Cycle Interstellar Medium GO 5 ------------------------------------------------------------------------------------ 5. Investigators Contact? PI: Silvia Torres-Peimbert Universidad Nacional Autonoma de Mexico CoI: Reginald J. Dufour Rice University N CoI: Manuel Peimbert Universidad Nacional Autonoma de Mexico N CoI: Miriam Pe\ na Universidad Nacional Autonoma de Mexico N ------------------------------------------------------------------------------------ 6. Abstract We propose to carry out FOS spectroscopic observations of the C-poor halo PNe M2-29 and DDDM-1 to study their UV spectrum and determine accurate chemical abundances. M2-29 and DDDM-1 are the most deficient in Ar and S of their group. Accurate C and N abundances for these objects will permit us to: a) study the chemical evolution of the ISM in the early epochs of the formation of the Galaxy, b) determine the fraction of C in the interstellar medium at present produced by SNe of Types II and Ib and the fraction produced by stars with initial masses < 8 Msun (the progenitors of PNe and SNeIa), c) constrain observationally the nuclear reaction rate C(Alpha,Gamma)O by comparing the observed C/O ratio in the primitive halo with the C/O ratio predicted from SNe models, and d) study and constrain the stellar evolution models of low mass stars, those with initial masses in the 0.8 - 1 Msun range. During HST Cycle 3 we obtained WFC1 direct imagery in HAlpha of these two very small objects. From these we now have information on their morphology and the surface brightness for planning FOS spectroscopy. In addition, we have discovered a "jet" structure in M2-29 which, in itself, merits spectroscopic study possible only with HST FOS. ------------------------------------------------------------------------------------ 6031( 10) - 09/20/95 11:21 - [ 2] Observations Description ------------------------ FOS spectroscopy through the 0.9" circular aperture of two PNe: (A) DDCM-1 is a small PN with little or no extinction. Observations to be done centered on the star. (B) M2-29 is an extended nebula about 5" in diameter with an apparent jet oriented at PA ~ -11 degrees. Observations to be done on the condensation (or jet). The "expected" surface brightness for the bright UV lines are listed in the table with C/O limits set by previous IUE observations for C and NII 6583 observations from the ground. These are based on the conservative assumptions that C/O ~0.1 for DDDM-1 and for M2-29. If we fail to detect the C lines, we still would have important results on the upper limit of C/O. PK061+41.1=DDDM-1.- We propose to cover the 1300-6820A region with 5 FOS gratings. The exposures are: a ~40 min (or longer) at G130H to measure CIV 1550, then an 18 min exposure at G190H to measure CIII 1909 and NIII 1750, an 8 min exposure at G270H to measure CII 2326 and short exposures with G400H and G570H to cover the total spectral range. We further expect to measure other important diagnostics (NV 1240, OIV 1402, NIV 1488, as well as possibly the central star continuum -- to obtain an improved temperature). It requires 1 visit of 3 orbits duration. We need 1 orbit for acquisition and the short exposure G400H a second orbit for G190H, G270H & G570H, and a third orbit for the long exposure G130H (43 min; or the longest we can expose). PK004-03.1=M2- 29.- The main effort would be to obtain a 40 min (or longer) G190H exposure to measure CIII 1909 and obtain a significant upper limit for NIII 1750. We also require require G400H and G570H exposures since our ground-based spectra essentially cover the entire nebula and are not appropriate to use to tie-in the HST spectra if the nebula is stratified. It requires 1 visit of 3 orbits duration. Emission Line Surface Brightness and FOS Exposure Calculations ------ ----------------------------------------------------------------- 1550A 1750A 1909A 2326A 3727A 5007A 6563 Notes DDDM-1 8.0\-14 5.1\-14 1.4\-13 9.0\-14 1.5\-12 5.5\-12 3.8\-12 (1) CPS(0.9") 0.33 0.91 3.4 4.9 146. 550. 191. (2) EXP(min) 38 18 18 8 1 1 1 (3) NetCounts 752 982 3670 2350 9640 33000 9190 (4) S/N 27 31 60 49 98 181 96 (5) ----------------------------------------------------------------------- M2-29 ... 3\-15 3.1\-15 ... 1.4\-14 3.6\-13 4.5\-13 (1) CPS(0.9") ... 0.054 0.076 ... 1.36 36. 23. (2) EXP(min) ... 55 55 ... 10 3 3 (3) NetCounts ... 178 251 ... 900 6470 3260 (4) S/N ... 13 16 ... 28 80 57 (5) Setup G130H G190H G190H G270H G400H G570H G570H (6) Efficienc 0.005 0.020 0.025 0.045 0.055 0.039 0.012 (7) ------------------------------------------------------------------------- Notes: (1) Surface brightness in ergs cm-2 s-1 squarearcsec-1; (2) Counts s- 1diode-1 (for FWHM ~ 2.2 diodes); (3) OSF exposure time in minutes; (4) Net counts collected per diode; (5) Approximate S/N per diode without consideration of underlying continuum; (6) Setup: G130H with Blue Digicon, others with Red Digicon; (7) HST+FOS efficiency. Real Time Justification ----------------------- None Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 6031( 10) - 09/20/95 11:21 - [ 3] Data Distribution Media: 8MM Blocking Factor: 10 Ship To: PI_Address Ship Via: DHL 991509322 Email: , ------------------------------------------------------------------------------------ 6031( 10) - 09/20/95 11:21 - [ 4] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 PK061+41.1 ISM, Planetary Nebula RA=16H 40M 18.21S +/- 0.5S, 2000 V=-304 V=15.6 +/- 0.5 DEC=+38D 42' 20.8" +/- 0.5", B-V = 0.7 +/- 0.1 PLATE-ID=00CL E(B-V)=0.0 TYPE=O SURF-LINE(1550) = 8.0 +/- 0.9 E- 14 SURF-LINE(1750) = 5.1 +/- 0.9 E-14 SURF-LINE(1909) = 1.4 +/- 0.5 E-13 SURF-LINE(2326) = 9.0 +/- 0.9 E-15 SURF-LINE(3727) = 1.5 +/- 0.4 E-12 Comments: Planetary Nebula. SURF-LINE(5007) = 5.5 +/- 0.1 E-12 SURF-LINE(6563) = 3.8 +/- 0.1 E-12 3 PK004-03.1 ISM, Planetary Nebula RA=18H 06M 40.903S +/- 0.02S, 2000 V=-103 V=17.7 +/- 0.5 DEC=-26D 54' 56.53" +/- 0.3", B-V = 0.0 PLATE-ID=067R E(B-V)=0.65 TYPE=O Comments: Central Star of the PN; it is in a crowded field. 4 PK004-03.1- ISM, Planetary Nebula R= 1.2", PA= 349D, FROM 3 2000 V=-103 A(V)=1.95 +/- 0.10 SURF-LINE(1750) = 3.0 KNOT +/- 0.9 E-15 SURF-LINE(1909) = 3.1 +/- 0.5 E-15 SURF-LINE(3727) = 1.4 +/- 0.4 E-14 SURF-LINE(5007) = 3.6 +/- 0.1 E-13 SURF-LINE(6563) = 4.5 +/- 0.1 E-13 Comments: This is the bright knot in the PN. 6031( 10) - 09/20/95 11:21 - [ 5] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 PK061+41.1 FOS/RD ACQ/PEA 4.3 G570H SCAN-STEP- 1 1S ONBOARD ACQ FOR 11 K Y=1.204, SEARCH -SIZE-Y=3, SEARCH-SIZE-X=1 ------------------------------------------------------------------------------------------------------------------------------------ 11 PK061+41.1 FOS/RD ACQ/PEA 1.0 G570H SCAN-STEP- 1 1S ONBOARD ACQ FOR 12 K Y=0.602, SCAN- STEP-X=0.602, SEARCH-SIZE- Y=2, SEARCH- Comments: SIZE-X=6 ------------------------------------------------------------------------------------------------------------------------------------ 12 PK061+41.1 FOS/RD ACQ/PEA 0.3 G570H SCAN-STEP- 1 4S ONBOARD ACQ FOR 20-25 K Y=0.172, SCAN- STEP-X=0.172, SEARCH-SIZE- Y=5, SEARCH- Comments: SIZE-X=5 ------------------------------------------------------------------------------------------------------------------------------------ 20 PK061+41.1 FOS/RD ACCUM 1.0 G400H 1 78S ------------------------------------------------------------------------------------------------------------------------------------ 21 PK061+41.1 FOS/RD ACCUM 1.0 G570H 1 60S ------------------------------------------------------------------------------------------------------------------------------------ 22 PK061+41.1 FOS/RD ACCUM 1.0 G270H 1 480S ------------------------------------------------------------------------------------------------------------------------------------ 24 PK061+41.1 FOS/RD ACCUM 1.0 G190H 1 1140S ------------------------------------------------------------------------------------------------------------------------------------ 25 PK061+41.1 FOS/BL ACCUM 1.0 G130H 1 2400S ------------------------------------------------------------------------------------------------------------------------------------ 6031( 10) - 09/20/95 11:21 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 30 PK004-03.1 FOS/RD ACQ/PEA 4.3 G570H SCAN-STEP- 1 5.8S ONBOARD ACQ FOR 31 K Y=1.204, SEARCH -SIZE-Y=3, SEARCH-SIZE-X=1 ------------------------------------------------------------------------------------------------------------------------------------ 31 PK004-03.1 FOS/RD ACQ/PEA 1.0 G570H SCAN-STEP- 1 6S ONBOARD ACQ FOR 32 K Y=0.602, SCAN- STEP-X=0.602, SEARCH-SIZE- Y=2, SEARCH- Comments: SIZE-X=6 ------------------------------------------------------------------------------------------------------------------------------------ 32 PK004-03.1 FOS/RD ACQ/PEA 0.3 G570H SCAN-STEP- 1 10S ONBOARD ACQ FOR 41-43 K Y=0.172 SCAN- STEP-X=0.172 SEARCH-SIZE-Y=5 SEARCH-SIZE-X=5 ------------------------------------------------------------------------------------------------------------------------------------ 41 PK004-03.1- FOS/RD ACCUM 1.0 G570H 1 180S KNOT ------------------------------------------------------------------------------------------------------------------------------------ 42 PK004-03.1- FOS/RD ACCUM 1.0 G400H 1 600S KNOT ------------------------------------------------------------------------------------------------------------------------------------ 43 PK004-03.1- FOS/RD ACCUM 1.0 G190H 1 3000S KNOT ------------------------------------------------------------------------------------------------------------------------------------ 6031( 10) - 09/20/95 11:21 - [ 7] Summary Form for Proposal 6031 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations FOS/RD FOS/BL ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters SCAN-STEP-Y=1.204 SEARCH-SIZE-Y=3 SEARCH-SIZE-X=1 SEARCH-SIZE-X=6 SEARCH-SIZE-X=5 SEARCH-SIZE-Y=2 SCAN-STEP-Y=0.172 SCAN-STEP-X=0.172 SEARCH-SIZE-Y=5 SEARCH-SIZE-X=5 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category Interstellar Medium ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 11 ONBOARD ACQ FOR 12 ONBOARD ACQ FOR 20-25 ONBOARD ACQ FOR 31 ONBOARD ACQ FOR 32 ONBOARD ACQ FOR 41-43 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G570H G400H G270H G190H G130H ------------------------------------------------------------------------------------------------------------------------------------ Target Names PK061+41.1 PK004-03.1 PK004-03.1-KNOT ------------------------------------------------------------------------------------------------------------------------------------