Proposal_Information ! Section 4 Title: The Upper IMF in the Magellanic Clouds. II. Spatially Resolved Spectroscopy of New Compact Multiple Systems Proposal_Category: GO Scientific_Category: Hot Stars Cycle: 5 Investigators PI_name: Nolan R. Walborn PI_Institution: Space Telescope Science Institute CoI_Name: Laurent Drissen CoI_Institution: Laval University Contact: ! Y or N (designate at most one contact) CoI_Name: Daniel J. Lennon CoI_Institution: Munich University Contact: ! Y or N (designate at most one contact) CoI_Name: John W. MacKenty CoI_Institution: Space Telescope Science Institute Contact: ! Y or N (designate at most one contact) CoI_Name: Joel Wm. Parker CoI_Institution: Goddard Space Flight Center Contact: ! Y or N (designate at most one contact) CoI_Name: Abhijit Saha CoI_Institution: Space Telescope Science Institute Contact: ! Y or N (designate at most one contact) CoI_Name: Richard L. White CoI_Institution: Space Telescope Science Institute Contact: ! Y or N (designate at most one contact) Abstract: ! Free format text (please update) Spectroscopy of a compact WN+OB group in the 30 Doradus periphery will be performed with FOS, to pursue a study of the upper IMF begun with WF/PC UBV images in Cycle 3, which newly resolved it into multiple stellar components. These observations will provide information relevant to the upper stellar mass limit, as well as the evolutionary relationships between the peculiar objects and their normal OB companions. The spectroscopy is also essential to define the upper HRD and IMF, since the temperatures and masses of O stars are indeterminate from continuum measurements such as UBV photometry alone. Previous ground-based spectroscopy has integrated over several comparable components in this object; only the optically corrected HST/FOS can observe the spectra of the WN stars and their OB companions separately. About a dozen components in this group will be observed and analyzed to determine their individual physical parameters and collective evolutionary status. Questions ! Free format text (please update) Observing_Description: We propose to observe the spectra of 11 members of the compact multiple system Breysacher 73 in the 30 Dor B region. UBV magnitudes have been measured from the Cycle 3 WF/PC images and used to calculate the spectroscopic exposure times. The relevant magnitudes are in the 14-16 range; we require the 0.3" aperture due to crowding for most stars and S/N = 70 to compensate the relatively low G400H resolution for blue-violet spectral classification and atmospheric analysis. Our detailed target-acquisition strategies, exposure-time estimates, and resultant orbit requirements are as follows. Target acquisition strategy: Since the relative positions of the stars in the cluster are known to within 0.03" from our Cycle 3 WF/PC images, we can use offsets to move the telescope from one star to the next. We will use a cluster member as an offset star. This star (30DorB-7; V=14.85) is 2.5" away from any other star. It will be acquired with a 3-stage PEAKUP (using the 1.0 aperture, and then the 0.3" twice); then a spectrogram will be obtained. The telescope will then slew from star to star within the cluster. Since the stars are all within a few arcseconds of each other, the error due to the slew movement is negligible. In order to make sure that the stars are always well centered, we will re-acquire the offset star once (orbit 5). We will also perform an ACQ/PEAK with the 0.3 aperture (3 X 3-0.05" steps) for 3 stars (1A, 1B, and 5) in very crowded regions. Spectra of relatively isolated stars (7, 6, 4, and 3) will be obtained with a larger aperture to decrease the exposure times and avoid more peak-up acquisitions. Because (a) Fig 1.2.1 in the FOS manual can no longer be used, the exposure times have to be increased by 30% to get the desired S/N ratio, and (b) the overheads and the acquisition take longer than estimated in phase I, one more orbit than the number allocated (8) would be necessary to complete our project. The total number of orbits is now 9. If it becomes impossible to schedule the 9th orbit without crossing the SAA, the last star to be observed (30DorB-6), and only this one, may be dropped from the target list. Example of exposure time calculation: According to the FOS manual, the count rate is given by Figure 1.2.3: for the 1.0 aperture and a source with F=1.0e-14 erg cm^-2 s^-1 A^-1 (corresponding to B=14.5, as for star 30DorB-2A), one gets 8 counts/s/diode. According to Figure 1.2.2, the transmission of the 0.3 aperture is (0.8/0.93=) 0.85 that of the 1.0 aperture, or 6.8 counts/s/diode. To get a S/N ratio of 70 per diode, we need to integrate for t = 70^2 / 6.8 = 720 s = 12 min. Real_Time_Justification: Our targets lie within the southern CVZ and we hope they might be scheduled as such; however, we are requesting non- CVZ orbit resources because the tables in the Proposal Instructions show only two 24-hr CVZ periods during the example year at our positions, and we do not wish to risk potential non-schedulability. Calibration_Justification: ! Move appropriate text from Real_Time_Justification Additional_Comments: Fixed_Targets ! Section 5.1 Target_Number: 1 Target_Name: 30DorB-OFFSET Alternate_Names: 30DorB-7 Description: EXT-STAR Position: RA=5H 37M 47.12S +/- 0.05S, DEC=-69D 09' 08.84" +/- 0.3" Equinox: 2000 Flux: V=14.85 +/- 0.1, B-V=0.13 Comments: Coordinates are from WF/PC image w1fk0506t.c0h; Target_Number: 2 Target_Name: 30DorB-1A Description: EXT-STAR Position: RA-OFF = -0.91S +/- 0.01S, DEC-OFF = -2.73" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=14.68 +/- 0.1, B-V=0.31 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (Feb 1, 1995 ApJLet) Target_Number: 3 Target_Name: 30DorB-1B Description: EXT-STAR Position: RA-OFF = -0.85S +/- 0.01S, DEC-OFF = -2.49" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=15.13 +/- 0.1, B-V=0.14 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Target_Number: 4 Target_Name: 30DorB-1C Description: EXT-STAR Position: RA-OFF = -0.84S +/- 0.01S, DEC-OFF = -3.68" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=15.40 +/- 0.1, B-V=0.19 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Target_Number: 5 Target_Name: 30DorB-2A Description: EXT-STAR Position: RA-OFF = -0.575S +/- 0.01S, DEC-OFF = -1.19" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=14.23 +/- 0.1, B-V=0.0.27 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Target_Number: 6 Target_Name: 30DorB-2B Description: EXT-STAR Position: RA-OFF = -0.53S +/- 0.01S, DEC-OFF = -0.65" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=15.21 +/- 0.1, B-V=0.10 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Target_Number: 7 Target_Name: 30DorB-2C Description: EXT-STAR Position: RA-OFF = -0.50S +/- 0.01S, DEC-OFF = -1.84" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=15.40 +/- 0.1, B-V=0.29 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Target_Number: 8 Target_Name: 30DorB-3 Description: EXT-STAR Position: RA-OFF = -0.985S +/- 0.01S, DEC-OFF = -1.09" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=14.26 +/- 0.1, B-V=0.22 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Target_Number: 9 Target_Name: 30DorB-4 Description: EXT-STAR Position: RA-OFF = -0.679S +/- 0.01S, DEC-OFF = -4.42" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=15.31 +/- 0.1, B-V=0.06 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Target_Number: 10 Target_Name: 30DorB-5 Description: EXT-STAR Position: RA-OFF = -0.376S +/- 0.01S, DEC-OFF = -3.53" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=15.34 +/- 0.1, B-V=0.02 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Target_Number: 11 Target_Name: 30DorB-6 Description: EXT-STAR Position: RA-OFF = -1.338S +/- 0.01S, DEC-OFF = -5.59" +/- 0.05", FROM 1 Equinox: 2000 Flux: V=15.49 +/- 0.1, B-V=-0.09 Comments: Offsets measured from WF/PC image w1fk0506t.c0h, Target name from Walborn et al (1995, ApJLet) Visits ! Section 6 Visit_Number: 1 Exposure_Number: 1 ! Section 6.5 Target_Name: 30DorB-OFFSET Config: FOS/RD Opmode: ACQ/PEAK Aperture: 1.0 Sp_Element: G400H Optional_Parameters: SCAN-STEP-X=0.60, SCAN-STEP-Y=0.60, SEARCH-SIZE-X=5, SEARCH-SIZE-Y=5 Number_of_Iterations: 1 Time_Per_Exposure: 0.5S Special_Requirements: ONBOARD ACQ FOR 2 ! Section 7.2 Exposure_Number: 2 ! Section 6.5 Target_Name: 30DorB-OFFSET Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: G400H Optional_Parameters: SCAN-STEP-X=0.17, SCAN-STEP-Y=0.17, SEARCH-SIZE-X=5, SEARCH-SIZE-Y=5 Number_of_Iterations: 1 Time_Per_Exposure: 0.5S Special_Requirements: ONBOARD ACQ FOR 3 ! Section 7.2 Exposure_Number: 3 ! Section 6.5 Target_Name: 30DorB-OFFSET Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: G400H Optional_Parameters:SCAN-STEP-X=0.05, SCAN-STEP-Y=0.05, SEARCH-SIZE-X=5, SEARCH-SIZE-Y=5 Number_of_Iterations: 1 Time_Per_Exposure: 5S Special_Requirements: ONBOARD ACQ FOR 4 ! Section 7.2 Exposure_Number: 4 ! Section 6.5 Target_Name: 30DorB-OFFSET Config: FOS/RD Opmode: ACCUM Aperture: 0.5 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 15M Exposure_Number: 5 ! Section 6.5 Target_Name: 30DorB-2B Config: FOS/RD Opmode: ACCUM Aperture: 0.3 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 25M Exposure_Number: 6 ! Section 6.5 Target_Name: 30DorB-2A Config: FOS/RD Opmode: ACCUM Aperture: 0.3 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 12M Exposure_Number: 7 ! Section 6.5 Target_Name: 30DorB-2C Config: FOS/RD Opmode: ACCUM Aperture: 0.3 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 35M Exposure_Number: 8 ! Section 6.5 Target_Name: 30DorB-1C Config: FOS/RD Opmode: ACCUM Aperture: 0.3 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 30M Exposure_Number: 9 ! Section 6.5 Target_Name: 30DorB-OFFSET Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: G400H Optional_Parameters:SCAN-STEP-X=0.05, SCAN-STEP-Y=0.05, SEARCH-SIZE-X=3, SEARCH-SIZE-Y=3 Number_of_Iterations: 1 Time_Per_Exposure: 5S Special_Requirements: ONBOARD ACQ FOR 10 ! Section 7.2 Exposure_Number: 10 ! Section 6.5 Target_Name: 30DorB-1A Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: G400H Optional_Parameters:SCAN-STEP-X=0.05, SCAN-STEP-Y=0.05, SEARCH-SIZE-X=3, SEARCH-SIZE-Y=3 Number_of_Iterations: 1 Time_Per_Exposure: 5S Special_Requirements: ONBOARD ACQ FOR 11 ! Section 7.2 Exposure_Number: 11 ! Section 6.5 Target_Name: 30DorB-1A Config: FOS/RD Opmode: ACCUM Aperture: 0.3 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 19M Exposure_Number: 12 ! Section 6.5 Target_Name: 30DorB-1B Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: G400H Optional_Parameters:SCAN-STEP-X=0.05, SCAN-STEP-Y=0.05, SEARCH-SIZE-X=3, SEARCH-SIZE-Y=3 Number_of_Iterations: 1 Time_Per_Exposure: 7S Special_Requirements: ONBOARD ACQ FOR 13 ! Section 7.2 Exposure_Number: 13 ! Section 6.5 Target_Name: 30DorB-1B Config: FOS/RD Opmode: ACCUM Aperture: 0.3 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 25M Exposure_Number: 14 ! Section 6.5 Target_Name: 30DorB-4 Config: FOS/RD Opmode: ACCUM Aperture: 0.5 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 23M Exposure_Number: 15 ! Section 6.5 Target_Name: 30DorB-3 Config: FOS/RD Opmode: ACCUM Aperture: 0.5 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 10M Exposure_Number: 16 ! Section 6.5 Target_Name: 30DorB-5 Config: FOS/RD Opmode: ACQ/PEAK Aperture: 0.3 Sp_Element: G400H Optional_Parameters:SCAN-STEP-X=0.05, SCAN-STEP-Y=0.05, SEARCH-SIZE-X=3, SEARCH-SIZE-Y=3 Number_of_Iterations: 1 Time_Per_Exposure: 7S Special_Requirements: ONBOARD ACQ FOR 17 ! Section 7.2 Exposure_Number: 17 ! Section 6.5 Target_Name: 30DorB-5 Config: FOS/RD Opmode: ACCUM Aperture: 0.3 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 20M Exposure_Number: 18 ! Section 6.5 Target_Name: 30DorB-6 Config: FOS/RD Opmode: ACCUM Aperture: 0.5 Sp_Element: G400H Number_of_Iterations: 1 Time_Per_Exposure: 25M Data_Distribution Medium: 8MM ! 8MM or 6250BPI or 1600BPI Blocking_Factor: 10 ! 10 or 1 Ship_To: PI_Address ! STSCI or PI_Address or Ship_Via: UPS ! UPS (2-day) or OVERNIGHT