15116( 12) - 14-Jun-2019 19:34:17 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15116 Version: 12 Check-in Time: 14-Jun-2019 19:34:17 STScI Edit Number: 9 Title Very Massive Stars in the Local Universe ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Linda J. Smith Space Telescope Science Institute - ESA Y CoI: Prof. Paul A. Crowther University of Sheffield N CoI: Prof. Daniela Calzetti University of Massachusetts - Amherst N CoI: Prof. Aida Wofford Universidad Nacional Autonoma de Mexico, N Obs. Astron. Nac. CoI: Dr. Bethan Lesley James Space Telescope Science Institute - ESA N CoI: Dr. Elena Sabbi Space Telescope Science Institute N CoI: Dr. Angela Adamo Stockholm University N CoI: Prof. Goeran Oestlin Stockholm University N CoI: Dr. Arjan Bik Stockholm University N CoI: Prof. Sally Oey University of Michigan N ------------------------------------------------------------------------------------ Abstract The upper mass limit for stars is unknown. Recent UV observations of young (< 3 Myr), massive star clusters (>5 x10^4 M_sun) suggest that stars substantially more massive than 100 M_sun exist. These very massive stars (VMS) are not properly accounted for in current stellar population synthesis (SPS) codes, even though they will dominate the ionization and mechanical feedback in star-forming regions for the first few Myr. VMS have been detected as resolved stars in the nearby LMC cluster R136 and in the integrated light of two young super star clusters in two nearby starburst galaxies. Since JWST will obtain numerous UV rest-frame spectra of young high redshift galaxies, it is essential that we investigate whether VMS are common in local, low metallicity analogs, while we still have access to the UV domain. We propose to obtain FUV STIS spectroscopy of young (< 3 Myr) super star clusters in 4 starbursting galaxies with the aim of establishing if VMS are commonly formed in dense star-forming events at low metallicity. The crucial spectral diagnostics for VMS are only available in the FUV, and we will use the spectroscopy together with new SPS models to constrain the upper mass limit to the initial mass function, and to test the importance of VMS for feedback. These spectra will form an important part of the UV legacy of HST and will provide an excellent local-universe analog to the rest-frame UV spectra of high-z galaxies to be obtained with JWST. ------------------------------------------------------------------------------------ Observations Description ------------------------ HST images were used to locate GSC2 stars to use as offsets. The offset to each target was measured from the offset star coordinates on the HST image. The slit orientation was chosen to pass through as many clusters as possible. A 4 point dither along the slit was chosen with a 0.5 arcsec spacing. The exposure times were determined using COS spectra of different regions in 15116( 12) - 14-Jun-2019 19:34:17 - [ 2] the galaxies and scaling using F140LP images. ------------------------------------------------------------------------------------ 15116( 12) - 14-Jun-2019 19:34:17 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 SBS0335-052E GALAXY, DWARF COMPACT, RA-OFF=-1.220S, DEC-OFF=1.82", J2000 V = 19.0 F(1400)=3.0E-15 STARBURST FROM 6 Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC1140 GALAXY, DWARF COMPACT, RA-OFF=-1.708S, DEC-OFF=-3.51", J2000 V = 18.0 F(1400) =2.0E-15 STARBURST FROM 8 ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC4449 GALAXY, DWARF COMPACT, RA-OFF=2.6264S, J2000 V = 17.5 F(1400)=1.7E-15 STARBURST DEC-OFF=-54.033", FROM 7 ------------------------------------------------------------------------------------------------------------------------------------ 6 SBS0335-052E STAR, F0-F2 RA=03H37M45.2510S +/- 0.1", J2000 V = 19.30 -OFFSET DEC=-05D02'42.27" +/- 0.1" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC4449-OFFS STAR, F3-F9 RA=12H28M11.3027S +/- 0.1", J2000 V = 15.7 ET DEC=+44D08'4.83" +/- 0.1" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC1140-OFFS STAR, F0-F2 RA=02H54M35.2290S +/- 0.1", J2000 V = 19.05 ET DEC=-10D01'36.56" +/- 0.1" Reference Frame: ICRS Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 9 SBS0335-052E STAR, F0-F2 RA=03H37M48.0762S +/- 0.1", J2000 V = 15.4 -OFFSET2 DEC=-05D02'9.94" +/- 0.1" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 10 SBS0335-052E GALAXY, DWARF COMPACT, RA-OFF=-4.0234S, J2000 V = 19.0 -2 STARBURST DEC-OFF=-30.474", FROM 9 Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 15116( 12) - 14-Jun-2019 19:34:17 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type STIS-ALONG-SLIT Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.5 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 90.0 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 15116( 12) - 14-Jun-2019 19:34:17 - [ 5] Visit: 01 (SBS0335-052E) Visit Requirements: ORIENT 90.0D TO 90.0 D; ORIENT 270.0D TO 270.0 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SBS0335-052 STIS/CCD ACQ F28X50LP MIRROR 1 20 S (20 GS ACQ SCENARIO BASE1B3 E-OFFSET S) ------------------------------------------------------------------------------------------------------------------------------------ 2 SBS0335-052 STIS/FUV ACCUM 52X0.2 G140L 1425 1 1000 S PATTERN 1 2 E -MAMA see below (4692 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SBS0335-052 STIS/FUV ACCUM 52X0.2 G140L 1425 1 1000 S PATTERN 1 3 E -MAMA see below (5140 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SBS0335-052E-OFFSET 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A SBS0335-052E 2 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none none none 1 1109.0 S -MAMA SBS0335-052E 2 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none none none 1 1013 S -MAMA SBS0335-052E 2 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none none none 2 1351.0 S -MAMA SBS0335-052E 2 STIS/FUV ACCUM 52X0.2 G140L 1425 4 none none none 2 1219.0 S -MAMA SBS0335-052E 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none none none 3 1355 S -MAMA SBS0335-052E 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none none none 3 1215.0 S -MAMA SBS0335-052E 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none none none 4 1355 S -MAMA SBS0335-052E 3 STIS/FUV ACCUM 52X0.2 G140L 1425 4 none none none 4 1215.0 S -MAMA 15116( 12) - 14-Jun-2019 19:34:17 - [ 6] Visit: 02 (NGC4449) Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC4449-OFF STIS/CCD ACQ F28X50LP MIRROR 1 1 S (1 S) GS ACQ SCENARIO SINGLE SET ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC4449 STIS/FUV ACCUM 52X0.2 G140L 1425 1 1000 S PATTERN 1 2 -MAMA see below (5289 S) Comments: STIS.sp.1016820 - check on counts - BOP - no GALEX data Reines et al. (2010, ApJ, 708, 26) give a flux density for the target S26 of 1.3 E-14 erg/s/cm^2/A with the F170W WFPC2 filter. This is the shortest wavelength observation. The region S26 is much larger than the 0.2 arcsec STIS slit so this is a strong upper limit. Using the STIS ETC, the above flux at 1821 A (central wavelength of F170W), assuming an O3 V spectral type and no reddening, gives the number of counts as 0.65 c/s so the target is safe. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC4449 STIS/FUV ACCUM 52X0.2 G140L 1425 1 1000 S PATTERN 1 3 -MAMA see below (5812 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC4449-OFFSET 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A NGC4449 2 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none none none 1 1193.0 S -MAMA NGC4449 2 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none none none 1 1190.0 S -MAMA NGC4449 2 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none none none 2 1401.0 S -MAMA NGC4449 2 STIS/FUV ACCUM 52X0.2 G140L 1425 4 none none none 2 1505.0 S -MAMA NGC4449 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none none none 3 1401 S -MAMA 15116( 12) - 14-Jun-2019 19:34:17 - [ 7] Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC4449 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none none none 3 1505.0 S -MAMA NGC4449 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none none none 4 1401 S -MAMA NGC4449 3 STIS/FUV ACCUM 52X0.2 G140L 1425 4 none none none 4 1505.0 S -MAMA 15116( 12) - 14-Jun-2019 19:34:17 - [ 8] Visit: 03 (NGC1140) Visit Requirements: ORIENT 48D TO 48 D; ORIENT 228D TO 228 D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC1140-OFF STIS/CCD ACQ F28X50LP MIRROR 1 10 S (10 GS ACQ SCENARIO BASE1B3 SET S) ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC1140 STIS/FUV ACCUM 52X0.2 G140L 1425 1 1000 S PATTERN 1 2 -MAMA see below (4940 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ NGC1140-OFFSET 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A NGC1140 2 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none none none 1 1113.0 S -MAMA NGC1140 2 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none none none 1 1113.0 S -MAMA NGC1140 2 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none none none 2 1357.0 S -MAMA NGC1140 2 STIS/FUV ACCUM 52X0.2 G140L 1425 4 none none none 2 1357.0 S -MAMA 15116( 12) - 14-Jun-2019 19:34:17 - [ 9] Visit: 51 (SBS0335-052E) Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 SBS0335-052 STIS/CCD ACQ F28X50LP MIRROR 1 1 S (1 S) GS ACQ SCENARIO BASE1B3 E-OFFSET2 ------------------------------------------------------------------------------------------------------------------------------------ 2 SBS0335-052 STIS/FUV ACCUM 52X0.2 G140L 1425 1 1000 S PATTERN 1 2 E-2 -MAMA see below (4768 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 SBS0335-052 STIS/FUV ACCUM 52X0.2 G140L 1425 1 1000 S PATTERN 1 3 E-2 -MAMA see below (5140 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ SBS0335-052E-OFFSET 1 STIS/CCD ACQ F28X50LP MIRROR none none none none 1 N/A 2 SBS0335-052E-2 2 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none none none 1 1109.0 S -MAMA SBS0335-052E-2 2 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none none none 1 1089.0 S -MAMA SBS0335-052E-2 2 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none none none 2 1351.0 S -MAMA SBS0335-052E-2 2 STIS/FUV ACCUM 52X0.2 G140L 1425 4 none none none 2 1219.0 S -MAMA SBS0335-052E-2 3 STIS/FUV ACCUM 52X0.2 G140L 1425 1 none none none 3 1355 S -MAMA SBS0335-052E-2 3 STIS/FUV ACCUM 52X0.2 G140L 1425 2 none none none 3 1215.0 S -MAMA SBS0335-052E-2 3 STIS/FUV ACCUM 52X0.2 G140L 1425 3 none none none 4 1355 S -MAMA SBS0335-052E-2 3 STIS/FUV ACCUM 52X0.2 G140L 1425 4 none none none 4 1215.0 S -MAMA 15116( 12) - 14-Jun-2019 19:34:17 - [ 10] Summary Form for Proposal 15116 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures 52X0.2, F28X50LP ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD, STIS/FUV-MAMA ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1B3, GS ACQ SCENARIO SINGLE, ORIENT 228D TO 228 D, ORIENT 270.0D TO 270.0 D, ORIENT 48D TO 48 D, ORIENT 90.0D TO 90.0 D, PATTERN 1 2, PATTERN 1 3 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G140L, MIRROR ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC1140, NGC1140-OFFSET, NGC4449, NGC4449-OFFSET, SBS0335-052E, SBS0335-052E-2, SBS0335-052E-OFFSET, SBS0335-052E-OFFSET2 ------------------------------------------------------------------------------------------------------------------------------------