Page 1 PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID 5678 Report Date: 18-Jul-95:17:51 Version: ********** Check-in Date: ********** 1.Proposal Title: RESOLUTION OF THE UPPER IMF IN THE MAGELLANIC CLOUDS:CYCLE4 ------------------------------------------------------------------------------------ 2. Scientific Category 3. Proposal For 4. Proposal Type 5. Continuation ID HOT STARS GO/CAR 4322 Sub Category YOUNG CLUSTERS ------------------------------------------------------------------------------------ 6. Principal Investigator Institution Country Telephone Nolan R. Walborn STSCI USA ------------------------------------------------------------------------------------ 7. Abstract Determination of the highly significant upper end of the initial mass function in extragalactic systems is subject to serious systematic error due to the combination of limited spatial resolution and the tendency of the most massive stars to occur in compact groups. These effects cause the luminosities to be overestimated and the numbers underestimated. The Magellanic Clouds provide the most favorable case, but even there compact systems remain a challenge. GTO observations of the 30 Doradus central cluster have demonstrated the substantial contribution which HST can make to the problem. This program will obtain UBV images with WF/PC of 5 important fields in the Magellanic Clouds other than the 30 Doradus cluster, in which recent ground- based and HST spectroscopy of extremely massive stars has been performed. It is absolutely vital to ascertain the multiplicity status of these images, even at the 0.1 arc sec level, for useful interpretation of the spectroscopic data. The use of 3 colors will enable reddening estimates to be made, and corrected color-magnitude diagrams and IMFs to be constructed, the latter with consultation of the spectroscopic results. The analysis of these images will provide a substantial advance over current knowledge of the upper IMF, and they represent an optimum use of HST in its present optical state, which would not be significantly enhanced by the refurbishment. ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ 9. Est obs time (hours) pri: 0.50 par: 0 10. Num targs pri: 5 par: 0 ------------------------------------------------------------------------------------ 11. Instruments requested: WF/PC ------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------ Page 2 I. GENERAL FORM Proposal 5678 PI: Nolan R. Walborn Proposal Title: RESOLUTION OF THE UPPER IMF IN THE MAGELLANIC CLOUDS:CYCLE4 ------------------------------------------------------------------------------------ 1. Proposers: Proposers Institution Country ESA ------------------------------------------------------------------------------------ Pi Nolan R. Walborn STSCI USA John W. Mackenty STSCI USA Abhijit Saha STSCI USA Richard L. White STSCI USA Joel Wm Parker NASA GODDARD SPACE FLIGHT CENTER USA ------------------------------------------------------------------------------------ 3. Description of proposed observations. Five fields in the Magellanic Clouds are observed with the WFPC to examine bright (V=12 to 16) magnitude O stars for multiplicity (and to determine magnitudes and colors of the separated components--if any). Each field is observed with either the PC or the WFC as determined by the size of the region with O stars. Each field is observed in U,B, and V. Exposure times are short (4 to 80 seconds). Two exposures in each filter are obtained to remove cosmic rays. It is critical that all 6 exposures of each field be obtained with the stars on the same pixels (SAME POS requirement). Preflash and Fine lock guiding are also required. The observations are grouped within 12H but it should be possible to obtain each field in 1 or 2 visibility periods as these fields are in or near the CVZ. Please direct change queries both to PI and John MacKenty x4559. ------------------------------------------------------------------------------------ 4. Justification of need for HST observations. All of these regions have been investigated from the ground. HST resolution is required to address the principal scientific objective: the multiplicity of the best current candidates for the most massive stars, those of type O3 in the Magellanic Clouds, and its implication for the upper IMF. In the case of NGC346, the PC images will provide an essential complement to FOS UV spectroscopic observations during Cycle 1. ------------------------------------------------------------------------------------ 5. Description of special scheduling requirements. No special realtime data or special scheduling is required. Note that these targets are in or near the CVZ and an increase in spacecraft efficiency is possible if they are scheduled to utilize this fact. ------------------------------------------------------------------------------------ 6. Description of special calibration exposures. No special calibration required. ------------------------------------------------------------------------------------ 9. Description of previous HST work. NRW (CoI): 1186, Imagery and UV Spectroscopy of Matter Ejected from Eta Carinae NRW " : 2233, The Physics of Massive O-Stars in Different Parent Galaxies NRW " : 2338, Spectroscopy of the Speckle-Resolved Eta Carinae Point Sources NRW " : 3815, UV Observations of the Hubble-Sandage Variables in M31 and M33 JWM (PI) : 3698, A Snapshot Survey of the Nuclear Regions of 102 Markarian Galaxies JWM (CoI) : 3538, UV Spectroscopy of Extended Emission-Line Regions Around QSOs AS (CoI) : 2547, Calibration of Supernovae of Type I as Standard Candles Program 2233 will obtain FOS UV spectroscopy of several stars in NGC 346 to be imaged here. Page 3 ------------------------------------------------------------------------------------ 10. Resources to be supplied by investigator's institution(s). Much of the work will be supported through the associated grant requests, which include 1 month of scientist and 3 months of research assistant salaries as well as computer equipment and support. We have access to substantial data-analysis facilities and support personnel at the STScI in addition. JWM heads the STScI WF/PC technical support group, while AS and RLM also have considerable experience in the analysis of HST images. ------------------------------------------------------------------------------------ 11. Address Information Name: NOLAN R. WALBORN Category: PI Institution: STScI Address: 3700 SAN MARTIN DRIVE City: BALTIMORE State: MD Zip Code: 21218 Country: USA Telephone: (410) 338-4915 Telex (or e-mail): ------------------------------------------------------------------------------------ TARGET LIST a) Fixed Targets ID = 5678 [ 4] ------------------------------------------------------------------------------------------------------------------------------------ 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| | | | | | | | | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC346 D,203 PLATE-ID=06B1, 2000 1 V = 13 RA= 00H59M02.1S +/-1S, DEC= -72D10'31" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ 2 HD32228 D,203 RA= 04H56M34.5S +/-1S, 2000 1 V = 13 LUCKE-HODGE9 DEC= -66D28'25" +/- 1" ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5678 [ 5] ------------------------------------------------------------------------------------------------------------------------------------ 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 ------------------------------------------------------------------------------------------------------------------------------------ 1.1 DEF # WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 2 6S 1 GROUP 1.1-1.6 SEQPC ATD-GAIN=15 WITHIN 12H SAME POS FOR 1.2- 1.6 AS 1.1 CYCLE 4 / 1.1-2.6 ------------------------------------------------------------------------------------------------------------------------------------ 1.2 DEF # WFPC2 IMAGE PC1 F336W CR-SPLIT=NO 1 12S 3 SEQPC ATD-GAIN=15 Comments: omit 1.2 if seq wont fit in 1 orbit ------------------------------------------------------------------------------------------------------------------------------------ 1.3 DEF # WFPC2 IMAGE PC1 F439W CR-SPLIT=NO 2 7S 1 SEQPC ATD-GAIN=15 ------------------------------------------------------------------------------------------------------------------------------------ 1.4 DEF # WFPC2 IMAGE PC1 F439W CR-SPLIT=NO 1 14S 3 SEQPC ATD-GAIN=15 Comments: omit 1.4 if seq wont fit in 1 orbit ------------------------------------------------------------------------------------------------------------------------------------ 1.5 DEF # WFPC2 IMAGE PC1 F569W CR-SPLIT=NO 2 2.3S 1 SEQPC ATD-GAIN=15 ------------------------------------------------------------------------------------------------------------------------------------ 1.6 DEF # WFPC2 IMAGE PC1 F569W CR-SPLIT=NO 1 5S 2 SEQPC ATD-GAIN=15 ------------------------------------------------------------------------------------------------------------------------------------ 2.1 DEF # WFPC2 IMAGE WF3-FIX F336W CR-SPLIT=NO 2 4S 1 GROUP 2.1-2.6 SEQWF ATD-GAIN=15 WITHIN 12H SAME POS FOR 2.2- 2.6 AS 2.1 ------------------------------------------------------------------------------------------------------------------------------------ 2.2 DEF # WFPC2 IMAGE WF3-FIX F336W CR-SPLIT=NO 1 8S 3 SEQWF ATD-GAIN=15 Comments: omit 2.2 if seq wont fit in 1 orbit ------------------------------------------------------------------------------------------------------------------------------------ 2.3 DEF # WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 2 4S 1 SEQWF ATD-GAIN=15 ------------------------------------------------------------------------------------------------------------------------------------ 2.4 DEF # WFPC2 IMAGE WF3-FIX F439W CR-SPLIT=NO 1 8S 3 SEQWF ATD-GAIN=15 Comments: omit 2.4 if seq wont fit in 1 orbit ------------------------------------------------------------------------------------------------------------------------------------ 2.5 DEF # WFPC2 IMAGE WF3-FIX F569W CR-SPLIT=NO 2 1.6S 1 SEQWF ATD-GAIN=15 ------------------------------------------------------------------------------------------------------------------------------------ 2.6 DEF # WFPC2 IMAGE WF3-FIX F569W CR-SPLIT=NO 1 3S 2 SEQWF ATD-GAIN=15 ------------------------------------------------------------------------------------------------------------------------------------ 11 USE NGC346 SEQWF ------------------------------------------------------------------------------------------------------------------------------------ EXPOSURE LOGSHEET ID = 5678 [ 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 ------------------------------------------------------------------------------------------------------------------------------------ 12 USE HD32228 SEQPC ------------------------------------------------------------------------------------------------------------------------------------ Summary Form for Proposal 5678 [ 7] Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO ATD-GAIN=15 ------------------------------------------------------------------------------------------------------------------------------------ Proposal for GO/CAR ------------------------------------------------------------------------------------------------------------------------------------ S/C Hours 0.50 ------------------------------------------------------------------------------------------------------------------------------------ Scientific Category HOT STARS ------------------------------------------------------------------------------------------------------------------------------------ Scientific Sub-category YOUNG CLUSTERS ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 1.1-1.6 WITHIN 12H; SAME POS FOR 1.2-1.6 AS 1.1; CYCLE 4 / 1.1-2.6 GROUP 2.1-2.6 WITHIN 12H; SAME POS FOR 2.2-2.6 AS 2.1; ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W F439W F569W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC346 HD32228 LUCKE-HODGE9 ------------------------------------------------------------------------------------------------------------------------------------