Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5731 Report Date: 18-Jul-95:17:54 Version: ********** Check-in Date: ********** 1.Proposal Title: THE NATURE OF GASEOUS LOOPS IN THE MILKY WAY HALO - GO CARRYOVER ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID INTERSTELLAR MEDIUM GO/CAR 3706 Sub Category ABSORPTION LINES ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Laura Danly SPACE TELESCOPE SCIENCE INST USA 301-338-4730 ------------------------------------------------------------------------------------ 7. Abstract Recent evidence has shown that the nature of the gaseous halos of galaxies both depends upon and contributes to the nature of the underlying disk. "Galactic fountain" theories propose that hot gas produced in the disk rises to large scale height where it cools and flows back to the disk in a rain of cool clouds. Because of their anomolous negative velocities, the high latitude neutral hydrogen clouds are thought to be the returning gas in this halo circulation scheme. Most of the infalling gas is found in large, coherent loop-like structures toward the North Galactic Pole. We propose to study halo circulation by observing the kinematics and ionization balance the intermediate velocity clouds through absorption line observations of both high and low ionization species. By studying the ionization balance, we hope to determine the nature of the gas heating and cooling processes. Together with the kinematic information available through high spectral resolution GHRS data, we expect to be able to place severe constraints upon galactic circulation models. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 4.58 par: 0 10. Num targs pri: 3 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: HRS ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5731 PI: Laura Danly Proposal Title: THE NATURE OF GASEOUS LOOPS IN THE MILKY WAY HALO - GO CARRYOVER ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Laura Danly SPACE TELESCOPE SCIENCE U.S.A. INSTITUTE Robert Benjamin UNIVERSITY OF TEXAS AT AUSTIN U.S.A. Kip D. Kuntz SPACE TELESCOPE SCIENCE U.S.A. INSTITUTE Elise Albert UNITED STATES NAVAL ACADEMY U.S.A. Paul Shapiro UNIVERSITY OF TEXAS AT AUSTIN U.S.A. ------------------------------------------------------------------------------------ 3. Description of proposed observations. We propose to observe three lines of sight with the GHRS through the SSA each at three settings of grating G160M. The line of sights are toward the stars: HD 121800: l=113, b=49, V=9.1, B-V=+0.04, E(B-V)=0.06, Spectral type B2 V, D=2200 pc, Z=1650 pc BD+49 2137: l=134, b=66, V=10.7, Spectral type B7 V, Z=1600 pc BD+38 2182: l=182, b=62, V=11.2, B-V=-0.22, E(B-V)=0.02, Spectral type B2 V, D=4600 pc, Z=4100 pc \bigskip The three grating settings are centered as follows: 1. 1550 \AA. (Useable range 1534\AA - 1566\AA ) This setting will obtain the C IV $\lambda$$\lambda$1548-1550 lines. This setting will also obtain the weak C I line at $\lambda$1560, which will be used with the HI data to understand the neutral component. 2. 1403 \AA. (Useable range 1387\AA - 1419\AA ) This setting will obtain the Si IV $\lambda$$\lambda$1393,1402 lines. Comparing these line strengths to the C IV line strengths is a principle diagnostic for hot gas. 3. 1249 \AA. (Useable range 1233\AA - 1265\AA ) This setting will obtain the N V $\lambda$1238-1242 lines. The high ionization potential of N V (77.5 eV) means that this line is a good diagnostic of hot gas. This setting will also obtain the strong low ionization lines S II $\lambda$1250, $\lambda$1253, $\lambda$1259, Si II $\lambda$1260. These low ionization lines are important diagnostics of the "warm" gas, as their spread of f-values allows a wide range of sensitivity. The exposure times were chosen to achieve S/N=50 and detection limits of about 4 mA for the HD 121800 line of sight, and S/N=30 and detection limits of about 7 mA for the BD+49 2137 and BD+38 2182 lines of sight. These signal to noise ratios will be appropriate for modeling, and will be adequate for the comparison with Space Telescope archive data for HD 93512. There are exposures of HD 121800 scheduled as part of GO program No.2257, however, the GO (Blair Savage) has not yet determined how to reshape his program in the light of the changest in the observatory capabilities. If there are exposures of HD 121800 taken as part of that program, we will utilize the archival spectra when they become available. Page 3 ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. High resolution, high S/N observations of a range of ions (including C IV, Si IV and N V) are necessary to study the nature of the ionization in the IV arch. Previous data taken with the IUE satellite are shown in Figure 3. While the data are tantalizing, they lack sufficient resolution and S/N to address the specific objectives of this proposal. In order to observe the highly ionized species at high resolution (about 13 km/s) and high S/N (S/N$\sim$30 for BD +38 2182 and BD +49 2137; S/N$\sim$50 for HD 121800) we require the capabilities of the GHRS on HST. Over the past decade, we have pursued studies of galactic halo gas using ground based optical, 21-cm H I, and IUE ultraviolet observations. Results from these extensive studies have laid the groundwork for the scientific objectives of this proposal. However, only the proposed HST observations will result in sufficiently high quality cloud column densities and velocites to compare with specific predictions of models for cooling gas. No ground based facilities or other space based facilities are capable of provided the data required to address the scientific issues outlined in this proposal. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. Wave calibrations are required for all nine GHRS spectra (3 spectra for each of 3 stars). see below. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. Wave calibrations are required for all nine GHRS spectra (3 spectra for each of 3 stars). This was not included in the Phase I proposal, but is now recognized as critical to the success of the program. Absolute velocity calibration to about 2-3 km/s is required. Each wave calibration must be performed with no gap immediately preceeding each spectral exposure. ------------------------------------------------------------------------------------ 8. Additional comments or special requests. This proposal is one of several programs (including an accepted GO program; see Question 8) designed to study gas in the environments of galaxies. These programs have been tailored specifically to meet the objectives outlined in the P.I.'s (accepted) Hubble Fellowship proposal. The goal of the Hubble Fellowship research is to study gas which is in the vicinity of a variety of galaxies, and is therefore subjected to a range of interstellar and intergalactic environments. Central to this research is a detailed study of the production and maintenance of Milky Way halo gas, where we can expect to obtain the highest quality data and develop the most detailed models. Accurate means to interpret quantitative spectroscopic data are critical to the interpretation of QSO absorption lines. Related Cycle 2 proposals include: $\bullet$ ``Spectroscopic Investigations of a Possible Galactic Chimney" (Danly, L, Albert, C. E., and Kuntz, K. D.) $\bullet$ ``A detailed Study of Nearby Ly$\alpha$ Systems" (Urry, C. M., Boggess, A., Maraschi, L., Danly, L., Bruhweiler, F. C., Falomo, R., Grady, C. A., Tanzi, E. G., and Treves, A.) $\bullet$ ``The Distance of High Velocity Clouds" (Wakker, B. P., Danly, L., Schwarz, U. J., and Van Woerden, H.) $\bullet$ ``Quasar Absorption Line Studies of Starburst Galaxy Enviornments" (Norman, C. N., Blades, J. C., Danly, L., and Heckman, T. J.) ------------------------------------------------------------------------------------ 9. Description of previous HST work. \ques{\phantom{8.} a. List HST program numbers and titles, and specify whether they are related to this project or not.} Proposal No. 2644, ``The Environments of Starburst Galaxies: Absorption-Line Studies of Galactic Outflows This GO program is related to the objectives of this proposal as described in Question 7. \ques{\phantom{8.} b. Summarize the main results obtained from previous related programs.} The data have not yet been obtained \ques{\phantom{8.} c. List publications resulting from the above data (Format: Title, Authors, Journal, Volume, Page, and Year.)} N/A (see 8b) Page 4 ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). The Space Telescope Science Institute has a wide variety of hardware and software systems to support the research proposed here. These include STSDAS, IDL, and KDAF which are supported on both the VAX cluster and the Sun Workstations. ------------------------------------------------------------------------------------ 11. Address Information Name: LAURA DANLY Category: PI Institution: SPACE TELESCOPE SCIENCE INSTITUTE Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: 301-338-4422 Telex (or e-mail): 684-9101-STSCI-411 ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5731 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial |Acqui|FLX| Flux data No | Name | Description | Position |Eqnx | Vel. |Prblm|REF| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 10 HD121800 A,110, PLATE-ID=01BR, J2000 V=13 1 V=9.1, TYPE=B2V, E(B-V)=0.06 GSC04177- G,508,510, RA= 13H 55M 15.4S +/- 0.2S, 2 B-V=-0.17 00880 DEC= +66D 7' 0.7" +/- 1" 3 F-CONT(1240) = 16 E-11 4 F-CONT(1400) = 1 E-10 5 F-CONT(1550) = 9 E-11 ------------------------------------------------------------------------------------------------------------------------------------ 20 BD+49D2137 G,508,510, PLATE-ID=024D, J2000 V=115 1 V=10.7, TYPE=B7V, E(B-V)=0.02 GSC03458- A,110, RA= 12H 25M 0.4S +/- 0.1S, 2 B-V=-0.14 00650 DEC= +49D 8' 30.4" +/- 1" 3 F-CONT(1240) = 2 E-12 4 F-CONT(1400) = 18 E-13 5 F-CONT(1550) = 17 E-13 ------------------------------------------------------------------------------------------------------------------------------------ 30 BD+38D2182 G,508,510, PLATE-ID=01R8, J2000 V=79 1 V=11.2, TYPE=B2V, E(B-V)=0.02 GSC03009- A,110, RA= 10H 49M 12.9S +/- 0.1S, 2 B-V=-0.22 02485 DEC= +38D 0' 14.5" +/- 1" 3 F-CONT(1240) = 36 E-13 4 F-CONT(1400) = 22 E-13 5 F-CONT(1550) = 17 E-13 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5731 [ 6] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HD121800 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 1.8S 1 1 ONBOARD ACQ FOR 1.10 CYCLE 4 / 1-2.7 ------------------------------------------------------------------------------------------------------------------------------------ 1.1 HD121800 HRS ACQ/ 0.25 MIRROR-N2 SEARCH-SIZE=5 1 5.0S 1 1 ONBOARD ACQ FOR PEAKUP 1.20 - 1.70 SEQ 1.2-1.7 NO GAP Comments: STEPTIME=0.2 ------------------------------------------------------------------------------------------------------------------------------------ 1.2 WAVE HRS ACCUM SC2 G160M 1249 STEP-PATT=5 1 DEF 1 CALIB FOR 1.3 ------------------------------------------------------------------------------------------------------------------------------------ 1.3 HD121800 HRS ACCUM 0.25 G160M 1249 FP-SPLIT=STD 1 544S 50 3 1 STEP-PATT=5 Comments: EXPOSURE TIME IS NEAREST INTEGER LARGER THAN INTEGER MULTIPLE OF 27.2 S ------------------------------------------------------------------------------------------------------------------------------------ 1.4 WAVE HRS ACCUM SC2 G160M 1403 STEP-PATT=5 1 DEF 1 CALIB FOR 1.5 ------------------------------------------------------------------------------------------------------------------------------------ 1.5 HD121800 HRS ACCUM 0.25 G160M 1403 FP-SPLIT=STD 1 871S 50 4 1 STEP-PATT=5 Comments: EXPOSURE TIME IS NEAREST INTEGER LARGER THAN INTEGER MULTIPLE OF 27.2 S ------------------------------------------------------------------------------------------------------------------------------------ 1.6 WAVE HRS ACCUM SC2 G160M 1550 STEP-PATT=5 1 DEF 1 CALIB FOR 1.7 ------------------------------------------------------------------------------------------------------------------------------------ 1.7 HD121800 HRS ACCUM 0.25 G160M 1550 FP-SPLIT=STD 1 1306S 50 5 1 STEP-PATT=5 Comments: EXPOSURE TIME IS NEAREST INTEGER LARGER THAN INTEGER MULTIPLE OF 27.2 S ------------------------------------------------------------------------------------------------------------------------------------ 2 BD+49D2137 HRS ACQ 2.0 MIRROR-N2 BRIGHT=RETURN 1 1.8S 1 1 ONBOARD ACQ FOR 2.10 ------------------------------------------------------------------------------------------------------------------------------------ 2.1 BD+49D2137 HRS ACQ/ 0.25 MIRROR-N2 SEARCH-SIZE=5 1 5.0S 1 1 ONBOARD ACQ FOR PEAKUP 2.20 - 2.70 SEQ 2.2-2.7 NO GAP Comments: STEPTIME=0.2 ------------------------------------------------------------------------------------------------------------------------------------ 2.2 WAVE HRS ACCUM SC2 G160M 1249 STEP-PATT=5 1 DEF 1 CALIB FOR 2.3 ------------------------------------------------------------------------------------------------------------------------------------ 2.3 BD+49D2137 HRS ACCUM 0.25 G160M 1249 FP-SPLIT=STD 1 27.2M 30 3 1 STEP-PATT=5 ------------------------------------------------------------------------------------------------------------------------------------ 2.4 WAVE HRS ACCUM SC2 G160M 1403 STEP-PATT=5 1 DEF 1 CALIB FOR 2.5 ------------------------------------------------------------------------------------------------------------------------------------ 2.5 BD+49D2137 HRS ACCUM 0.25 G160M 1403 FP-SPLIT=STD 1 27.2M 30 4 1 STEP-PATT=5 ------------------------------------------------------------------------------------------------------------------------------------ 2.6 WAVE HRS ACCUM SC2 G160M 1550 STEP-PATT=5 1 DEF 1 CALIB FOR 2.7 ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5731 [ 7] ------------------------------------------------------------------------------------------------------------------------------------ 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |10 | 11 | 12 |13 |14| 15 ------------------------------------------------------------------------------------------------------------------------------------ Line | Seq | Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | S/N |Flx|Pr| Special Number | Name | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| |Rel. Time|Ref| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 2.7 BD+49D2137 HRS ACCUM 0.25 G160M 1550 FP-SPLIT=STD 1 39.9M 30 5 1 STEP-PATT=5 ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5731 [ 8] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations HRS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACQ/PEAKUP ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BRIGHT=RETURN SEARCH-SIZE=5 STEP-PATT=5 FP-SPLIT=STD ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO/CAR ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 4.58 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category INTERSTELLAR MEDIUM ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category ABSORPTION LINES ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ONBOARD ACQ FOR 1.10; CYCLE 4 / 1-2.7 ONBOARD ACQ FOR 1.20 - 1.70; SEQ 1.2-1.7 NO GAP CALIB FOR 1.3; CALIB FOR 1.5; CALIB FOR 1.7; ONBOARD ACQ FOR 2.10; ONBOARD ACQ FOR 2.20 - 2.70; SEQ 2.2-2.7 NO GAP CALIB FOR 2.3; CALIB FOR 2.5; CALIB FOR 2.7; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR-N2 G160M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HD121800 GSC04177-00880 BD+49D2137 GSC03458-00650 BD+38D2182 GSC03009-02485 ------------------------------------------------------------------------------------------------------------------------------------