8161( 8) - 06/07/99 14:26 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8161 Version: 8 Check-in Date: 07-Jun-1999 14:26:05 1.Proposal Title: Boron in the Magellanic Clouds: A Novel Test of Light Element Formation ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 8 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Kim Venn Macalester College CoI: Dr. David L. Lambert University of Texas at Austin N CoI: Dr. Katia Cunha University of Texas at El Paso N CoI: Dr. Verne Smith University of Texas at El Paso N CoI: Dr. Norbert Langer University of Potsdam N CoI: Dr. Michael Lemke Sternwarte Bamberg N ------------------------------------------------------------------------------------ 5. Abstract Observations of boron abundances in the Magellanic Clouds will provide a novel test of the assertion that boron is produced primarily through spallation reactions between cosmic rays and ambient interstellar nuclei. The lower metallicities and especially the lower cosmic ray flux of the Small Magellanic Cloud, as inferred from Gamma--ray observations, imply that, if spallation is the dominant production mechanism, boron should be significantly underabundant in the Clouds relative to its local Galactic value. Only spectroscopy from space can provide the necessary boron abundances. In this proposal, we are requesting HST STIS observations to detect the B III resonance lines in one LMC and two SMC main-sequence B stars. Only STIS can observe these NUV lines, especially with the resolution and S/N required for reliable boron abundance determinations. The main-sequence stars selected for this project show no signs of stellar mixing (which could destroy B), thus they can be used to determine an accurate, present- day, boron abundance. This abundance will be compared with that predicted by simple models of galactic chemical evolution using the inferred cosmic ray fluxes and interstellar abundances of target nuclei. ------------------------------------------------------------------------------------ 8161( 8) - 06/07/99 14:26 - [ 2] Observations Description ------------------------ Table of Stellar Parameters, Fluxes, and Orbit Estimates Name - T/log g/vsini- V/E(B-V) - F2066 - S/N - ETC(min) - Orbits- K/cgs/(km/s) - --req'd- S/N=35 - req'd AV304 - 26500/3.9/14 - 14.98/0.04 - 4E-14 - 60 - 190- 9 CVZ NGC346-637 - 30500/4.0/28 - 14.98/0.12 - 7E-14 - 60 - 107 - 9 HD34078 - 31400/4.1/30 - 5.96/0.53 - 2E-11 - 20 - 1 - 1 We are requesting observations of the B III 2066 A line in two SMC B-stars, which can only obtained using HST STIS + NUV/MAMA detectors. These stars have low rotational velocities, and thus sharp absorption lines necessary to observe the B III line in the crowded UV spectrum. In addition, we will also detect several Fe III in the spectral region. Using STIS + G230M + 52x0.05 slit (2 pixels), a resolution of R~10, 000 (30, km s^-1) is obtainable. The minimum S/N estimates to measure 12+log(B/H)=1.0 in all targets are listed in the Table above. Exposure times have been calculated based on flux estimates at 2066 A from Kurucz model atmospheres, and using the ETC (STIS + G230M + 52x0.05; with the exception of the bright standard star HD34078 for which STIS + E230H + 0.2x0.06 has been used). For all three stars, multiple exposures are required to obtain the requisite total S/N (e.g., S/N=50 -- 60 can be obtained by adding two -- three exposures with S/N=35). The CVZ is requested for only one SMC target; regular orbits are requested for the other targets. Estimating 96 minutes per orbit for CVZ target, 58 minutes per regular orbit for all targets, 25 minutes for overheads (typical for GSA, TAR/ACQ, ACQ-PEAKUP, WAVE), and 6 minutes for each GS-reACQ, then the total number of orbits per star are listed in the Table above. Detailed break down of the orbits requested is shown in another Table below. Table of Orbit Estimates Name - S/N - ETC - Break down per exposure - total-req'd-S/N=35- (in minutes)- orbits AV304 - 60 - 190 - 3x[(25 ovhd +71 exp) +2x(6 ovhd +90 exp)] - 9 CVZ NGC346- 60 - 107 - 3x[(25 ovhd +33 exp) +2x(6 ovhd +52 exp)] - 9 Real Time Justification ----------------------- The CVZ has been requested for one of our targets. The observation requires a very long integration to build the S/N at the requisite resolution, thus use of the CVZ is ideal. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ Data Distribution Paper Products: YES Media: 8MM_HI Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 8161( 8) - 06/07/99 14:26 - [ 3] TARGET LIST a) Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 10 AV304 EXT-STAR, B0-B2 V-IV, RA=01H 2M 21.43S +/- 0.10S, DEC= J2000 V = 14.98+/-0.05 STAR -72D 39' 14.64" +/-0.10", PLATE- E(B-V) = 0.1+/-0.05 ID=06B1 B-V = -0.20+/-0.05 F(2006)=4.0+/-0.5e-14 TYPE=B2V 20 NGC346-637 EXT-STAR, B0-B2 V-IV, RA=00H 59M 14.62S +/- 0.10S, J2000 V = 14.98+/-0.05 STAR DEC=-72D 11' 58.81" +/-0.10", E(B-V) = 0.1+/-0.05 PLATE-ID=06B1 B-V = -0.16+/-0.05 F(2066)=7.0+/-0.5e-14 TYPE=B0V 30 HD34078 STAR, MAIN SEQUENCE O RA=05H 16M 18.15S +/- 0.1S, J2000 V = 5.59+/-0.38 DEC=34D 18' 44.3" +/- 0.1" B-V = 0.119+/-0.006 E(B-V) = 0.45+/-0.1 TYPE=O9.5V Comments: Coordinates are from the Hipparcos Output Catalogue 8161( 8) - 06/07/99 14:26 - [ 4] Visit: 01 Visit Priority: Visit Requirements: CVZ 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 AV304 STIS/C ACQ F28X50L MIRROR 1 1 S ONBOARD ACQ FOR 11-13 CD P ------------------------------------------------------------------------------------------------------------------------------------ 11 AV304 STIS/C ACQ/PEA 52X0.05 MIRROR 1 1 S ONBOARD ACQ FOR 12-13 CD K ------------------------------------------------------------------------------------------------------------------------------------ 12 AV304 STIS/N ACCUM 52X0.05 G230M 2095 9 42 M NO SPLIT UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 13 AV304 STIS/N ACCUM 52X0.05 G230M 2095 1 41 M NO SPLIT UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8161( 8) - 06/07/99 14:26 - [ 5] Visit: 02 Visit Priority: Visit Requirements: CVZ 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 AV304 STIS/C ACQ F28X50L MIRROR 1 1 S ONBOARD ACQ FOR 11, 12 CD P ------------------------------------------------------------------------------------------------------------------------------------ 11 AV304 STIS/C ACQ/PEA 52X0.05 MIRROR 1 1 S ONBOARD ACQ FOR 12 CD K ------------------------------------------------------------------------------------------------------------------------------------ 12 AV304 STIS/N ACCUM 52X0.05 G230M 2095 7 47.5 M NO SPLIT UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8161( 8) - 06/07/99 14:26 - [ 6] Visit: 03 Visit Priority: 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 NGC346-637 STIS/C ACQ F28X50L MIRROR 1 1 S ONBOARD ACQ FOR 11, 12, CD P 13 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC346-637 STIS/C ACQ/PEA 52X0.05 MIRROR 1 1 S ONBOARD ACQ FOR 12, 13 CD K ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC346-637 STIS/N ACCUM 52X0.05 G230M 2095 1 33 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC346-637 STIS/N ACCUM 52X0.05 G230M 2095 3 54 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8161( 8) - 06/07/99 14:26 - [ 7] Visit: 04 Visit Priority: 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 NGC346-637 STIS/C ACQ F28X50L MIRROR 1 1 S ONBOARD ACQ FOR 11, 12, CD P 13 ------------------------------------------------------------------------------------------------------------------------------------ 11 NGC346-637 STIS/C ACQ/PEA 52X0.05 MIRROR 1 1 S ONBOARD ACQ FOR 12, 13 CD K ------------------------------------------------------------------------------------------------------------------------------------ 12 NGC346-637 STIS/N ACCUM 52X0.05 G230M 2095 1 33 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 13 NGC346-637 STIS/N ACCUM 52X0.05 G230M 2095 4 54 M UV-MAM A ------------------------------------------------------------------------------------------------------------------------------------ 8161( 8) - 06/07/99 14:26 - [ 8] Visit: 05 Visit Priority: 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 ------------------------------------------------------------------------------------------------------------------------------------ 12 HD34078 STIS/C ACQ F28X50O MIRROR 1 0.1 S ONBOARD ACQ FOR 13, 14, CD III 15, 16 ------------------------------------------------------------------------------------------------------------------------------------ 13 HD34078 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 0.1 S ONBOARD ACQ FOR 14, 15, CD K 5ND 16 Comments: Linear Peak-Up ND=2 ------------------------------------------------------------------------------------------------------------------------------------ 14 HD34078 STIS/C ACQ/PEA 0.1X0.0 G230LB 2375 1 5 S ONBOARD ACQ FOR 15, 16 CD K 3 Comments: Spiral Peak-Up (follows Linear Peak-Up in Exposure #13 of this visit) ------------------------------------------------------------------------------------------------------------------------------------ 15 HD34078 STIS/N ACCUM 0.1X0.0 E230H 2063 1 6 M UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 16 HD34078 STIS/N ACCUM 0.1X0.0 E230H 2013 1 6 M UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 8161( 8) - 06/07/99 14:26 - [ 9] Summary Form for Proposal 8161 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.05 F28X50OIII 0.2X0.05ND 0.1X0.03 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements CVZ ONBOARD ACQ FOR 11-13 ONBOARD ACQ FOR 12-13 NO SPLIT ONBOARD ACQ FOR 11, 12 ONBOARD ACQ FOR 12 ONBOARD ACQ FOR 11, 12, 13 ONBOARD ACQ FOR 12, 13 ONBOARD ACQ FOR 13, 14, 15, 16 ONBOARD ACQ FOR 14, 15, 16 ONBOARD ACQ FOR 15, 16 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G230M G230LB E230H ------------------------------------------------------------------------------------------------------------------------------------ Target Names AV304 NGC346-637 HD34078 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 2095 2375 2063 2013 ------------------------------------------------------------------------------------------------------------------------------------