7305( 11) - 06/17/99 15:14 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 7305 Version: 11 Check-in Date: 17-Jun-1999 15:13:35 1.Proposal Title: The Physical Characteristics of Small- Scale ISM Structure ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 7 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: David Meyer Northwestern University CoI: J. Chris Blades Space Telescope Science Institute N CoI: John K. Watson Northwestern University N ------------------------------------------------------------------------------------ 5. Abstract We propose to use STIS to accurately measure and compare the interstellar Zn II, S II, Cr II, Mg II, Mn II, CO, Cl I, and C I absorption line profiles toward a sample of seven multiple star systems with projected linear separations ranging from 550 to 9700 AU. Recent optical observations of Na I at very high spectral resolution toward six of these systems and more than a dozen others have found line profile variations in every case that are indicative of small-scale structure in the diffuse ISM\@. A detailed physical understanding of this structure requires the diagnostic power of the many interstellar species observable in the ultraviolet. The specific scientific objectives of our proposed STIS observations are to: (1) assess the small-scale variations in terms of relatively undepleted, dominant ions like Zn II and S II; (2) determine the dust content of the structure using depleted, dominant ions such as Cr II, Mg II, and Mn II; (3) investigate the molecular content of the clumpiness with CO and Cl I; and (4) evaluate the thermal gas pressures of the small-scale structure using the fine-structure excitation of C I\@. The last of these goals is especially important in that the Na I variations imply the existence of a significant population of small, dense (n_H>~10^3 cm^-3) clumps that should be short-lived due to their overpressure with respect to the ambient diffuse ISM\@. ------------------------------------------------------------------------------------ 7305( 11) - 06/17/99 15:14 - [ 2] Observations Description ------------------------ begintableh begintabularccccccc Name & Separation (AU) & V & Spectral Type & Deltat_E140H (s) & Deltat_E230H (s) & Orbits , HD5788 & 1100 & 6.84 & A2 V & 10400 & 3100 & 6 , HD5789 & & 6.04 & B9.5 V & 1900 & 900 & 2 , HD6456 & 2500 & 5.34 & A0 IV & 2000 & 700 & 2 , HD6457 & & 5.56 & B9 V & 1900 & 750 & 2 , HD13294 & 2000 & 5.63 & B9 V & 850 & 500 & 2, HD13295 & & 6.10 & A1 V & 4000 & 1350 & 3 , HD32039 & 4800 & 7.03 & B9 V & 3100 & 1800 & 3 , HD32040 & & 6.66 & B9 V & 2200 & 1300 & 3 , HD57102 & 2400 & 6.53 & B9 V & 2000 & 1200 & 2 , HD57103 & & 5.45 & B8 V & 300 & 300 & 2 , HD150100 & 9700 & 5.53 & B9.5 V & 1200 & 600 & 2 , HD150117 & 550 & 5.56 & B9 V & 800 & 450 & 2 , HD150118 & & 6.58 & A1 V & 6200 & 2100 & 4 , HD170867 & 2800 & 5.65 & B9 V & 850 & 500 & 2 , HD170868 & & 6.32 & A0 III & 2500 & 1200 & 3 , endtabular endtable Our goal is to obtain high-resolution STIS echelle observations of the interstellar Zn II, S II, Cr II, Mg II, Mn II, CO, Cl I, and C I absorption line profiles toward the stars in the binary (and one triple) systems listed above. We can observe all of these lines (and more) with one setup of the E230H grating centered at 1963 Angstrom\ (covering 1824 to 2101 Angstrom) and another of the E140H grating centered at 1271 Angstrom\ (covering 1170 to 1372 Angstrom). The net exposure times listed above are those needed to achieve spectra with a S/N ratio of 50 at these central wavelengths. These times were calculated using the WWW STIS Spectroscopic Exposure Time Calculator for the 0.1x0.09 slit with the E230H grating and the 0.2x0.09 slit with the E140H grating. According to this Calculator, none of the setups on our targets violate the MAMA bright object count rate limits. By taking advantage of multiple exposures and Doppler shifting due to the spacecraft motion, we should be able to minimize any MAMA fixed pattern noise enough to achieve the potential S/N ratio of 50 yielded by the expected photon counts in our spectra. In this regard, we have a great deal of experience in maximizing the S/N ratios attainable with astronomical detectors (Meyer, Hawkins, & Wright 1993, ApJ, 409, L61; Meyer et al.\ 1994, ApJ, 437, L59). In calculating the number of orbits needed to complete our proposed observations of each star, we have allowed for all of the necessary acquisition and exposure overheads including the acquisition peakup exposure required for the use of the 0.1x0.09 slit. With separations ranging between 5" and 95", the acquisitions of the stars comprising our binary targets should not present any special problems for STIS\@. Real Time Justification ----------------------- None. We plan on obtaining high resolution observations of the interstellar Na I D absorption toward the triple system HD150100/17/18 with the KPNO Coude Feed telescope next spring. This system is the only one among this proposal's sample without such data. Calibration Justification ------------------------- Real_Time_Justification Additional Comments ------------------- ------------------------------------------------------------------------------------ 7305( 11) - 06/17/99 15:14 - [ 3] Data Distribution Paper Products: Media: ELECTRONIC Blocking Factor: 10 Ship To: PI_Address Ship Via: Email: ------------------------------------------------------------------------------------ 7305( 11) - 06/17/99 15:14 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HD6456 STAR, A0-A3 V-IV RA=1H 05M 40.93S +/- 0.002", J2000 V = 5.34+/-0.01 DEC=+21D 28' 23.6" +/- 0.002" B-V = -0.025 TYPE=A0IV Comments: The coordinates are from the Hipparcos Output Catalogue. Although no far-UV spectra of this target exist, using scaled IUE spectra of stars of similar type and reddening we calculate (using the on-line ETC) for the E230H and E140H gratings that the narrow echelle slits will yield a count rate below the MAMA bright object safety limits. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.003174 -0.01432 0.0 2 HD6457 STAR, B6-B9.5 V-IV RA=1H 05M 41.68S +/- 0.004", J2000 V = 5.56+/-0.03 DEC=+21D 27' 55.7" +/- 0.003" B-V = -0.060 TYPE=B9V Comments: The coordinates are from the Hipparcos Output Catalogue. Although no far-UV spectra of this target exist, using scaled IUE spectra of stars of similar type and reddening we calculate (using the on-line ETC) for the E230H and E140H gratings that the narrow echelle slits will yield a count rate below the MAMA bright object safety limits. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.003863 -0.01263 0.0 3 HD32039 STAR, B6-B9.5 V-IV RA=5H 00M 32.53S +/- 0.03", J2000 V = 7.03+/-0.03 DEC=+03D 36' 53.4" +/- 0.02" B-V = -0.033 TYPE=B9V Comments: The coordinates are from the Hipparcos Output Catalogue. Although no far-UV spectra of this target exist, the fluxes calculated with the ETC B8 V template (an overestimate) and V=7.03 indicate that observations with the E140H grating and a narrow echelle slit will yield a count rate well below the FUV MAMA bright object safety limits. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.001205 -0.01465 0.0 4 HD32040 STAR, B6-B9.5 V-IV RA=5H 00M 33.93S +/- 0.01", J2000 V = 6.65+/-0.03 DEC=+03D 36' 56.9" +/- 0.01" B-V = -0.053 TYPE=B9V Comments: The coordinates are from the Hipparcos Output Catalogue. Although no far-UV spectra of this target exist, the fluxes calculated with the ETC B8 V template (an overestimate) and V=6.65 indicate that observations with the E140H grating and a narrow echelle slit will yield a count rate well below the FUV MAMA bright object safety limits. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 1991.25 0.000691 -0.02739 0.0 7305( 11) - 06/17/99 15:14 - [ 5] 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 ------------------------------------------------------------------------------------------------------------------------------------ 10 HD6456 STIS/C ACQ F28X50O MIRROR 1 0.1 S ONBOARD ACQ FOR 11 CD II ------------------------------------------------------------------------------------------------------------------------------------ 11 HD6456 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 0.1 S ONBOARD ACQ FOR 12-15 CD K 5ND ------------------------------------------------------------------------------------------------------------------------------------ 12 HD6456 STIS/F ACCUM 0.1X0.0 E140H 1271 1 870.0 S UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 13 HD6456 STIS/F ACCUM 0.1X0.0 E140H 1271 1 870.0 S UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 14 HD6456 STIS/F ACCUM 0.1X0.0 E140H 1271 1 960.0 S UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 15 HD6456 STIS/N ACCUM 0.1X0.0 E230H 1963 1 960.0 S UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 7305( 11) - 06/17/99 15:14 - [ 6] 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 ------------------------------------------------------------------------------------------------------------------------------------ 20 HD6457 STIS/C ACQ F28X50O MIRROR 1 0.1 S ONBOARD ACQ FOR 21 CD II ------------------------------------------------------------------------------------------------------------------------------------ 21 HD6457 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 0.1 S ONBOARD ACQ FOR 22-25 CD K 5ND ------------------------------------------------------------------------------------------------------------------------------------ 22 HD6457 STIS/F ACCUM 0.1X0.0 E140H 1271 1 870.0 S UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 23 HD6457 STIS/F ACCUM 0.1X0.0 E140H 1271 1 870.0 S UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 24 HD6457 STIS/F ACCUM 0.1X0.0 E140H 1271 1 960.0 S UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 25 HD6457 STIS/N ACCUM 0.1X0.0 E230H 1963 1 960.0 S UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 7305( 11) - 06/17/99 15:14 - [ 7] 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 ------------------------------------------------------------------------------------------------------------------------------------ 30 HD32039 STIS/C ACQ F28X50O MIRROR 1 0.1 S ONBOARD ACQ FOR 31 CD II ------------------------------------------------------------------------------------------------------------------------------------ 31 HD32039 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 0.1 S ONBOARD ACQ FOR 32-37 CD K 5ND ------------------------------------------------------------------------------------------------------------------------------------ 32 HD32039 STIS/N ACCUM 0.2X0.0 E230H 1963 1 840.0 S UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 33 HD32039 STIS/N ACCUM 0.2X0.0 E230H 1963 1 840.0 S UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 34 HD32039 STIS/F ACCUM 0.2X0.0 E140H 1271 1 1200.0 UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 35 HD32039 STIS/F ACCUM 0.2X0.0 E140H 1271 1 1200.0 UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 36 HD32039 STIS/F ACCUM 0.2X0.0 E140H 1271 1 1320.0 UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 37 HD32039 STIS/F ACCUM 0.2X0.0 E140H 1271 1 1320.0 UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 7305( 11) - 06/17/99 15:14 - [ 8] 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 ------------------------------------------------------------------------------------------------------------------------------------ 40 HD32040 STIS/C ACQ F28X50O MIRROR 1 0.1 S ONBOARD ACQ FOR 41 CD II ------------------------------------------------------------------------------------------------------------------------------------ 41 HD32040 STIS/C ACQ/PEA 0.2X0.0 MIRROR 1 0.1 S ONBOARD ACQ FOR 42-45 CD K 5ND ------------------------------------------------------------------------------------------------------------------------------------ 42 HD32040 STIS/F ACCUM 0.2X0.0 E140H 1271 1 840.0 S UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 43 HD32040 STIS/F ACCUM 0.2X0.0 E140H 1271 1 840.0 S UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 44 HD32040 STIS/F ACCUM 0.2X0.0 E140H 1271 1 960.0 S UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 45 HD32040 STIS/N ACCUM 0.2X0.0 E230H 1963 1 960.0 S UV-MAM 9 A ------------------------------------------------------------------------------------------------------------------------------------ 7305( 11) - 06/17/99 15:14 - [ 9] Visit: 51 Visit Priority: Visit Requirements: ORIENT 120D TO 210D ORIENT 300D TO 30D 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 ------------------------------------------------------------------------------------------------------------------------------------ 50 HD6456 STIS/C ACQ F25ND3 MIRROR 1 0.1 S ONBOARD ACQ FOR 51 CD ------------------------------------------------------------------------------------------------------------------------------------ 51 HD6456 STIS/C ACQ/PEA 0.2X0.0 G230LB 2375 1 3.5 S ONBOARD ACQ FOR 52 CD K 9 ------------------------------------------------------------------------------------------------------------------------------------ 52 HD6456 STIS/C ACQ/PEA 0.1X0.0 G230LB 2375 1 3.5 S ONBOARD ACQ FOR 53-55 CD K 3 ------------------------------------------------------------------------------------------------------------------------------------ 53 HD6456 STIS/F ACCUM 0.1X0.0 E140H 1271 1 1200.0 UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 54 HD6456 STIS/F ACCUM 0.1X0.0 E140H 1271 1 1360.0 UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 55 HD6456 STIS/N ACCUM 0.1X0.0 E230H 1963 1 1060.0 UV-MAM 3 A ------------------------------------------------------------------------------------------------------------------------------------ 7305( 11) - 06/17/99 15:14 - [ 10] Summary Form for Proposal 7305 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50OII 0.2X0.05ND 0.1X0.03 0.2X0.09 F25ND3 ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD STIS/FUV-MAMA STIS/NUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAK ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 11 ONBOARD ACQ FOR 12-15 ONBOARD ACQ FOR 21 ONBOARD ACQ FOR 22-25 ONBOARD ACQ FOR 31 ONBOARD ACQ FOR 32-37 ONBOARD ACQ FOR 41 ONBOARD ACQ FOR 42-45 ORIENT 120D TO 210D ORIENT 300D TO 30D ONBOARD ACQ FOR 51 ONBOARD ACQ FOR 52 ONBOARD ACQ FOR 53-55 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR E140H E230H G230LB ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD6456 HD6457 HD32039 HD32040 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 1271 1963 2375 ------------------------------------------------------------------------------------------------------------------------------------