! Proposal 6457, submission 2 ! PI: David M. Meyer ! Received Tue Jan 30 16:58:55 EST 1996 ! From: hrsmeyer@hrssun.gsfc.nasa.gov ! Hubble Space Telescope Cycle 6 (1996) Phase II Proposal Template ! ! 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: Alice Berman ! Phone: 410-338-4462 , E-mail: aberman@stsci.edu ! ! This partially completed template was generated from a Phase I proposal. ! Proposal_Information ! Section 4 Title: The Abundance of Interstellar Nitrogen Proposal_Category: GO Scientific_Category: INTERSTELLAR MEDIUM Cycle: 6 Investigators PI_name: David M. Meyer PI_Institution: Northwestern University CoI_Name: U. J. Sofia CoI_Institution: Villanova University Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) We propose to utilize the sensitivity of the GHRS onboard HST to establish an accurate set of gas-phase nitrogen abundances from high S/N observations of the interstellar N I absorption in six sightlines characterized by low fractional abundances of molecular hydrogen. Similar observations of interstellar oxygen and carbon have recently found ``underabundances'' of these elements with respect to their solar values even after reasonable contributions from dust grains are considered. The total (gas + dust) interstellar O abundance inferred (about 2/3 solar) is remarkably similar to the median value found in nearby B stars. Observations of interstellar nitrogen can potentially provide a better understanding of the observed C and O underabundances since N, unlike C and O, may not be significantly present in dust. Our goal is to determine the abundance of nitrogen in the local ISM to an accuracy capable of discriminating between a solar and a B-star N abundance. Establishing the CNO underabundances as cosmic in nature would be important in understanding similar deficits in the abundance of interstellar boron and krypton in the context of Galactic chemical evolution. On the other hand, a set of nitrogen abundances that are more consistent with dust depletion from a solar standard would also be interesting in terms of reconciling the B-star abundances and understanding how to ``hide'' an appreciable fraction of the N and O in the diffuse ISM\@. Questions ! Free format text (please update) Observing_Description: begintableh begintabularccccccccc Name & & Spectral Type & & V & & Log H_total^a & & Log f(H_2 )^b , Gamma Cas (HD 5394) & & B0 IV & & 2.47 & & 20.16 & & <-2.36 , Lambda Ori (HD 36861) & & O8 V & & 3.66 & & 20.83 & & -1.41 , Iota Ori (HD 37043) & & O9 III & & 2.77 & & 20.20 & & -5.21 , Kappa Ori (HD 38771) & & B0.5 Ia & & 2.09 & & 20.52 & & - 4.54 , Delta Sco (HD 143275) & & B0 IV & & 2.32 & & 21.16 & & -1.45 , Kappa Sco (HD 160578) & & B1.5 III & & 2.41 & & 20.36 & & <-5.83 , endtabular beginraggedright, ^alog of the total column density of hydrogen nuclei, H_total = 2H_2 + H I, ^blog of the fractional abundance of hydrogen nuclei in H_2, f(H_2) = 2H_2/H_total, endraggedright endtable The table above lists the attributes of the sightlines in which we plan to obtain high S/N GHRS echelle observations of interstellar nitrogen. All observations will be made using the LSA, in order to take advantage of the maximum throughput, and a sampling strategy of two substeps per diode. The slight (20\ resolution in the post-COSTAR LSA relative to the SSA will not impact our analysis. The N I observations will involve wavelength setups with ECH-A near 1160 Angstrom\ (order 48). Allowing sufficient time for guide star acquisition (8 min), target acquisition (11 min), and the ACCUM exposure overheads (4 min each), our goal is to achieve the highest possible S/N ratio for each of our N I spectra in one orbit per target with the use of the FP-Split option to better assess and remove the effects of fixed pattern noise. For our faintest UV target, Lambda Ori, we can attain an ECH-A spectrum of N I with a S/N ratio of 300 in two 12 min FP-Split exposures that fill the visibility window. In the case of our brightest target, Gamma Cas, two FP-Split exposures each of 14 min duration will result in a S/N ratio of 500 at 1160 Angstrom\@. We will take these multiple FP-Split exposures of each star at slightly different wavelength settings to assist in the fixed pattern noise removal. Data of this quality will insure that we obtain accurate (better than 5Sigma) abundances of interstellar nitrogen in all of our targeted sightlines. Our exposure estimates account for the ECH-A blaze efficiency and are based on the post-COSTAR LSA throughput given in the GHRS Cycle 6 Handbook. The proposers are very experienced in making such calculations as well as reducing and analyzing high S/N GHRS data. Real_Time_Justification: None. None. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: HD5394 Alternate_Names: gamma-cas Description: STAR, BE Position: RA=00H 56M 42.52S +/- 0.03S, DEC=+60D 43' 00.3" +/- 0.5" Equinox: J2000 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=2.47, B-V=-0.15 Comments: Target_Number: 2 Target_Name: HD36861 Alternate_Names: lambda-ori Description: STAR, OE Position: RA=05H 35M 08.22S +/- 0.03S, DEC=+09D 56' 02.6" +/- 0.5" Equinox: J2000 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=3.66, B-V=-0.18 Comments: Target_Number: 3 Target_Name: HD37043 Alternate_Names: iota-ori Description: STAR, GIANT O Position: RA=05H 35M 25.94S +/- 0.03S, DEC=-05D 54' 35.6" +/- 0.5" Equinox: J2000 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=2.77, B-V=-0.24 Comments: Target_Number: 4 Target_Name: HD38771 Alternate_Names: kappa-ori Description: STAR, B0-B2 III-I Position: RA=05H 47M 45.38S +/- 0.03S, DEC=-09D 40' 10.8" +/- 0.5" Equinox: J2000 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=2.06, B-V=-0.17 Comments: Target_Number: 5 Target_Name: HD143275 Alternate_Names: delta-sco Description: STAR, B0-B2 V-IV Position: RA=16H 00M 20.01S +/- 0.03S, DEC=-22D 37' 18.0" +/- 0.5" Equinox: J2000 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=2.32, B-V=-0.12 Comments: Target_Number: 6 Target_Name: HD160578 Alternate_Names: kappa-sco Description: STAR, B0-B2 III-I Position: RA=17H 42M 29.28S +/- 0.03S, DEC=-39D 01' 48.1" +/- 0.5" Equinox: J2000 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=2.41, B-V=-0.22 Comments: ! 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: ! Section 7.1 On_Hold_Comments: Visit_Comments: Exposure_Number: 1 ! Section 6.5 Target_Name: HD5394 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-A1 Wavelength: Optional_Parameters: BRIGHT=RETURN,SEARCH-SIZE=3 Number_of_Iterations: 1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 2-3 ! Section 7.2 Comments: Exposure_Number: 2 ! Section 6.5 Target_Name: HD5394 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.0 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 806.4S Special_Requirements: ! Section 7.2 Comments: Exposure_Number: 3 ! Section 6.5 Target_Name: HD5394 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.5 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 806.4S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 2 Visit_Requirements: ! Section 7.1 On_Hold_Comments: Visit_Comments: Exposure_Number: 4 ! Section 6.5 Target_Name: HD36861 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-N1 Wavelength: Optional_Parameters: BRIGHT=RETURN,SEARCH-SIZE=3 Number_of_Iterations: 1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 5-6 ! Section 7.2 Comments: STEP-TIME=0.2S Exposure_Number: 5 ! Section 6.5 Target_Name: HD36861 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.0 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 691.2S Special_Requirements: ! Section 7.2 Comments: Exposure_Number: 6 ! Section 6.5 Target_Name: HD36861 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.5 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 691.2S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 3 Visit_Requirements: ! Section 7.1 On_Hold_Comments: Visit_Comments: Exposure_Number: 7 ! Section 6.5 Target_Name: HD37043 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-A1 Wavelength: Optional_Parameters: BRIGHT=RETURN,SEARCH-SIZE=3 Number_of_Iterations: 1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 8-9 ! Section 7.2 Comments: Exposure_Number: 8 ! Section 6.5 Target_Name: HD37043 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.0 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 691.2S Special_Requirements: ! Section 7.2 Comments: Exposure_Number: 9 ! Section 6.5 Target_Name: HD37043 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.5 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 748.8S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 4 Visit_Requirements: ! Section 7.1 On_Hold_Comments: Visit_Comments: Exposure_Number: 10 ! Section 6.5 Target_Name: HD38771 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-A1 Wavelength: Optional_Parameters: BRIGHT=RETURN,SEARCH-SIZE=3 Number_of_Iterations: 1 Time_Per_Exposure: 1.8S Special_Requirements: ONBOARD ACQ FOR 11-12 ! Section 7.2 Comments: Exposure_Number: 11 ! Section 6.5 Target_Name: HD38771 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.0 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 691.2S Special_Requirements: ! Section 7.2 Comments: Exposure_Number: 12 ! Section 6.5 Target_Name: HD38771 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.5 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 748.8S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 5 Visit_Requirements: ! Section 7.1 On_Hold_Comments: Visit_Comments: Exposure_Number: 13 ! Section 6.5 Target_Name: HD143275 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-A1 Wavelength: Optional_Parameters: BRIGHT=RETURN,SEARCH-SIZE=3 Number_of_Iterations: 1 Time_Per_Exposure: 3.6S Special_Requirements: ONBOARD ACQ FOR 14-15 ! Section 7.2 Comments: Exposure_Number: 14 ! Section 6.5 Target_Name: HD143275 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.0 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 691.2S Special_Requirements: ! Section 7.2 Comments: Exposure_Number: 15 ! Section 6.5 Target_Name: HD143275 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.5 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 748.8S Special_Requirements: ! Section 7.2 Comments: Visit_Number: 6 Visit_Requirements: ! Section 7.1 On_Hold_Comments: Visit_Comments: Exposure_Number: 16 ! Section 6.5 Target_Name: HD160578 Config: HRS Opmode: ACQ Aperture: 2.0 Sp_Element: MIRROR-A1 Wavelength: Optional_Parameters: BRIGHT=RETURN,SEARCH-SIZE=3 Number_of_Iterations: 1 Time_Per_Exposure: 3.6S Special_Requirements: ONBOARD ACQ FOR 17-18 ! Section 7.2 Comments: Exposure_Number: 17 ! Section 6.5 Target_Name: HD160578 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.0 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 748.8S Special_Requirements: ! Section 7.2 Comments: Exposure_Number: 18 ! Section 6.5 Target_Name: HD160578 Config: HRS Opmode: ACCUM Aperture: 2.0 Sp_Element: ECH-A48 Wavelength: 1161.5 Optional_Parameters: FP-SPLIT=STD,STEP-PATT=6 Number_of_Iterations: 1 Time_Per_Exposure: 748.8S Special_Requirements: ! Section 7.2 Comments: Data_Distribution ! Defaults indicated; change if desired Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 ! Only astronomers with very old 9- ! track tape drives should consider ! a blocking factor of 1 Ship_To: PI_Address ! STSCI or PI_Address or ! PI Address from Phase I is: ! ! Department of Physics and Astro ! nomy ! Evanston ! 60208 ! ! Ship_Via: UPS ! UPS (2-day) or OVERNIGHT ! Overnight shipping done at PI expense Recipient_Email: ! Needed if Ship_To: is not PI_Address ! ! Let us know what you think of this template and software! ! Please send a list of your likes and dislikes to your Program Coordinator