Proposal_Information Title: UV SPECTROSCOPY OF TWO VERY C-POOR HALO PLANETARY NEBULAE Proposal_Category: GO Scientific_Category: Interstellar Medium Cycle: 5 Investigators PI_name: Silvia Torres-Peimbert PI_Institution: Universidad Nacional Autonoma de Mexico CoI_Name: Reginald J. Dufour CoI_Institution: Rice University Contact: N CoI_Name: Manuel Peimbert CoI_Institution: Universidad Nacional Autonoma de Mexico Contact: N CoI_Name: Miriam Pe\ na CoI_Institution: Universidad Nacional Autonoma de Mexico Contact: N 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. Questions Observing_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: Fixed_Targets Target_Number: 1 Target_Name: PK061+41.1 Alternate_Names: DDDM-1, IRAS 16385+3848 Description: ISM, Planetary Nebula Position: RA=16H 40M 18.21S +/- 0.5S, DEC=+38D 42' 20.8" +/- 0.5", PLATE-ID=00CL Equinox: 2000 RV_or_Z: V=-304 Flux: V=15.6 +/- 0.5, B-V = 0.7 +/- 0.1, 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, SURF-LINE(5007) = 5.5 +/- 0.1 E-12, SURF-LINE(6563) = 3.8 +/- 0.1 E-12 Comments: Planetary Nebula. Target_Number: 3 Target_Name: PK004-03.1 Alternate_Names: M2-29 Description: ISM, Planetary Nebula Position: RA=18H 06M 40.903S +/- 0.02S, DEC=-26D 54' 56.53" +/- 0.3", PLATE-ID=067R Equinox: 2000 RV_or_Z: V=-103 Flux: V=17.7 +/- 0.5, B-V = 0.0, E(B-V)=0.65, TYPE=O Comments: Central Star of the PN; it is in a crowded field. Target_Number: 4 Target_Name: PK004-03.1-KNOT Alternate_Names: M2-29 Description: ISM, Planetary Nebula Position: R= 1.2", PA= 349D, FROM 3 Equinox: 2000 RV_or_Z: V=-103 Flux: A(V)=1.95 +/- 0.10 SURF-LINE(1750) = 3.0 +/- 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. Visits Visit_Number: 1 Exposure_Number: 10 Target_Name: PK061+41.1 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 4.3 Sp_Element: G570H Optional_Parameters: SCAN-STEP-Y=1.204, SEARCH-SIZE-Y=3, SEARCH-SIZE-X=1 Number_of_iterations: 1 Time_Per_Exposure: 1S Special_Requirements: ONBOARD ACQ FOR 11 Exposure_Number: 11 Target_Name: PK061+41.1 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 1.0 Sp_Element: G570H Optional_Parameters: SCAN-STEP-Y=0.602, SCAN-STEP-X=0.602, SEARCH-SIZE-Y=2, SEARCH-SIZE-X=6 Number_of_iterations: 1 Time_Per_Exposure: 1S Special_Requirements: ONBOARD ACQ FOR 12 Exposure_Number: 12 Target_Name: PK061+41.1 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: G570H Optional_Parameters: SCAN-STEP-Y=0.172, SCAN-STEP-X=0.172, SEARCH-SIZE-Y=5, SEARCH-SIZE-X=5 Number_of_iterations: 1 Time_Per_Exposure: 4S Special_Requirements: ONBOARD ACQ FOR 20-25 Exposure_Number: 20 Target_Name: PK061+41.1 Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 1.3M Exposure_Number: 21 Target_Name: PK061+41.1 Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: G570H Number_of_Iterations: 1 Time_Per_Exposure: 1M Exposure_Number: 22 Target_Name: PK061+41.1 Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: G270H Number_of_Iterations: 1 Time_Per_Exposure: 8M Exposure_Number: 24 Target_Name: PK061+41.1 Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: G190H Number_of_Iterations: 1 Time_Per_Exposure: 19M Exposure_Number: 25 Target_Name: PK061+41.1 Config: FOS/BL Opmode: ACCUM Aperture: 1.0 Sp_Element: G130H Number_of_Iterations: 1 Time_Per_Exposure: 40M Visits Visit_Number: 2 Exposure_Number: 30 Target_Name: PK004-03.1 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 4.3 Sp_Element: G570H Optional_Parameters: SCAN-STEP-Y=1.204, SEARCH-SIZE-Y=3, SEARCH-SIZE-X=1 Number_of_iterations: 1 Time_Per_Exposure: 5.8S Special_Requirements: ONBOARD ACQ FOR 31 Exposure_Number: 31 Target_Name: PK004-03.1 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 1.0 Sp_Element: G570H Optional_Parameters: SCAN-STEP-Y=0.602, SCAN-STEP-X=0.602, SEARCH-SIZE-Y=2, SEARCH-SIZE-X=6 Number_of_iterations: 1 Time_Per_Exposure: 6.0S Special_Requirements: ONBOARD ACQ FOR 32 Exposure_Number: 32 Target_Name: PK004-03.1 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: G570H Optional_Parameters: SCAN-STEP-Y=0.172 SCAN-STEP-X=0.172 SEARCH-SIZE-Y=5 SEARCH-SIZE-X=5 Number_of_iterations: 1 Time_Per_Exposure: 10S Special_Requirements: ONBOARD ACQ FOR 41-43 Exposure_Number: 41 Target_Name: PK004-03.1-KNOT Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: G570H Number_of_Iterations: 1 Time_Per_Exposure: 3M Exposure_Number: 42 Target_Name: PK004-03.1-KNOT Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 10M Exposure_Number: 43 Target_Name: PK004-03.1-KNOT Config: FOS/RD Opmode: ACCUM Aperture: 1.0 Sp_Element: G190H Number_of_Iterations: 1 Time_Per_Exposure: 50M Data_Distribution Medium: 8MM Blocking_Factor: 10 Ship_To: PI_Address Ship_Via: DHL 991509322