8693( 2) - 03/02/00 13:30 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8693 Version: 2 Check-in Date: 02-Mar-2000 13:29:42 1.Proposal Title: Interstellar Boron & Oxygen Abundances in the Cep OB2 Association: Probing Neutrino Nucleosynthesis ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Verne Smith University of Texas at El Paso CoI: Dr. Katia Cunha University of Texas El Paso N CoI: Dr. Steve Federman University of Toledo N CoI: Dr. David L. Lambert University of Texas Austin N ------------------------------------------------------------------------------------ 5. Abstract A specific nuclear process associated with core-collapse supernovae involves the inelastic scattering of neutrinos (produced as a result of the core collapse) off of abundant nuclei in the outer layers of the dying star. Two relatively low-abundance elements, boron and fluorine, have been suggested to owe some uncertain fraction of their cosmic abundances to this process. In the case of boron, the dominant isotope is ^11B, and neutrinos interacting with ^12C can lead to its synthesis. Fluorine-19 is the only stable F isotope and it can be produced by neutrino scattering removing a proton from ^20Ne. Competing processes can also synthesyze these elements: cosmic- ray spallation reactions for B and shell He-burning in AGB stars for F. In order to gauge the importance of neutrino nucleosynthesis in the chemical evolution of the Galaxy, we will use HST with STIS to determine interstellar B and O abundances in the gas associated with the Cep OB2 association (using the B II 1362Angstrom\ and O I 1356Angstrom\ lines). These results will be combined with observations of interstellar F I along the same lines-of-sight obtained with FUSE (fluorine can only be compared directly to boron using interstellar lines and interstellar F is only observable with FUSE). The derived F/O and F/B ratios in Cep OB2 will allow us to determine the relative importance of neutrino nucleosynthesis to the origins of B and F. ------------------------------------------------------------------------------------ 8693( 2) - 03/02/00 13:30 - [ 2] Observations Description ------------------------ The B II line at 1362.461Angstrom\ and the O I 1355.598Angstrom\ will be observed towards three rapidly rotating early-B spectral-type members of Cep OB2. Using STIS with E140M, we will obtain about 600Angstrom\ of specta at a resolution of about R=45, 000. A signal-to-noise (S/N) ratio of 100 will be achieved and this is sufficiently high to accurately measure the expected B II and O I lines. Exposure times (below) were calculated using the STIS Time Estimator on the World-Wide-Web using the combination of spectral types, reddenings, and V-magnitudes, in combination with the Kurucz model grid based upon the spectral type. The exposure times plus the overhead times for STIS described in the Phase I Proposal Instructions were used to determine the number of orbits needed. begintabularlcclcr Target & V & E(B-V) & SpT & Exposure (min.), HD 207538 & 7.31 & 0.64 & B0V & 105 , HD 207308 & 7.49 & 0.50 & B0.5V & 61 , HD 208266 & 8.12 & 0.52 & B1V & 122 , endtabular Real Time Justification ----------------------- No special requirements We have already obtained high-resolution optical spectra (R=55, 000), from McDonald Observatory, for 36 lines-of-sight into Cep OB2. These spectra include interstellar lines of CH (Lambda4300), CH^+ (Lambda4232), and Ca I (Lambda4226) and we have used these data to select our three lines-of-sight. Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8693( 2) - 03/02/00 13:30 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD207538 STAR RA=21H 47M 39.79S +/-0.5", J2000 V = 7.31+/-0.02 DEC=+59D 42' 01.4" +/-0.5" Comments: Coordinates are from the Hipparcos Catalogue Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.0004 -0.0025 0.00030 2 HD207308 STAR RA=21H 45M 42.37S +/-0.5", J2000 V = 7.49+/-0.02 DEC=+62D 18' 30.0" +/-0.5" Comments: Coordinates are from the Hipparcos Catalogue Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.0003 -0.0041 0.00068 3 HD208266 STAR RA=21H 53M 00.35S +/-0.5", J2000 V = 8.12+/-0.02 DEC=+60D 38' 32.7" +/-0.5" Comments: Coordinates are from the Hipparcos Catalogue Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 -0.0004 -0.0030 0.0 8693( 2) - 03/02/00 13:30 - [ 4] Visit: 01 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD207538 STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 0.1 S CD II ------------------------------------------------------------------------------------------------------------------------------------ 2 HD207538 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 0.1 S CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 HD207538 STIS/F ACCUM 0.2X0.0 E140M 1425 1 2247 S UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 HD207538 STIS/F ACCUM 0.2X0.0 E140M 1425 1 3135 S UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8693( 2) - 03/02/00 13:30 - [ 5] Visit: 02 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD207308 STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 0.1 S CD II ------------------------------------------------------------------------------------------------------------------------------------ 2 HD207308 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 0.1 S CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 HD207308 STIS/F ACCUM 0.2X0.0 E140M 1425 1 2217 S UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 HD207308 STIS/F ACCUM 0.2X0.0 E140M 1425 1 3105 S UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8693( 2) - 03/02/00 13:30 - [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1 HD208266 STIS/C ACQ F28X50O MIRROR ACQTYPE=POINT 1 0.1 S CD II ------------------------------------------------------------------------------------------------------------------------------------ 2 HD208266 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 0.1 S CD K 6 ------------------------------------------------------------------------------------------------------------------------------------ 3 HD208266 STIS/F ACCUM 0.2X0.0 E140M 1425 1 2217 S UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 4 HD208266 STIS/F ACCUM 0.2X0.0 E140M 1425 1 3105 S UV-MAM 6 A ------------------------------------------------------------------------------------------------------------------------------------ 8693( 2) - 03/02/00 13:30 - [ 7] Summary Form for Proposal 8693 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50OII 0.2X0.06 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E140M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD207538 HD207308 HD208266 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1425 ------------------------------------------------------------------------------------------------------------------------------------