16045( 2) - 05-Dec-2019 21:34:11 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16045 Version: 2 Check-in Time: 05-Dec-2019 21:34:11 STScI Edit Number: 0 Title COS observations of a very young massive star cluster in the blue compact dwarf galaxy NGC 5253 ------------------------------------------------------------------------------------ Type Cycle GO 27 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Linda J. Smith Space Telescope Science Institute - ESA Y CoI: Dr. Angela Adamo Stockholm University N CoI: Dr. Arjan Bik Stockholm University N CoI: Prof. Daniela Calzetti University of Massachusetts - Amherst N CoI: Dr. Jenna Ryon Space Telescope Science Institute N CoI: Dr. Elena Sabbi Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract A high gas pressure environment is thought to be a prerequisite for both the formation of globular clusters in redshift > 2 galaxies and young massive star clusters (YMCs) in the nearby universe. Such high pressures are rare in the quiescent disks of nearby galaxies and YMCs are usually confined to galaxy mergers, starburst dwarf galaxies and nuclear regions where pressures are high. Local YMCs are excellent analogs to the proto-GCs that are now being discovered at high redshift through gravitational lensing. Since JWST will obtain rest-frame UV spectra of star-forming clumps/proto-GCs in high redshift galaxies, it is essential to obtain FUV spectra of YMCs in nearby galaxies, while we still have access to the UV domain. We have recently discovered a very young (< 1 Myr) massive star cluster close to the starburst core of the blue compact dwarf galaxy NGC 5253. We are asking for mid-cycle time for FUV COS spectroscopy because finding such a rare, young cluster still associated with its natal molecular cloud and observable at FUV wavelengths is potentially unique. FUV spectra of this cluster will be an essential addition to current COS surveys of young clusters in nearby galaxies. We will perform a detailed investigation of both the stellar content and the cluster wind interaction with the interstellar medium. We will determine the age and obtain information on the IMF by searching for the signature of very massive stars. The COS FUV spectrum will act as a benchmark for high redshift studies by defining the FUV spectral characteristics of massive stars at the youngest ages, and the importance of early feedback on the ISM. ------------------------------------------------------------------------------------ Observations Description ------------------------ This program obtains COS spectroscopy of cluster #12 in NGC 5253 with the G130M and G160M gratings. The target is acquired using an offset star to ensure that cluster #12 is properly centered. The offset star is acquired via ACQ/IMAGE, the offset is performed and a short NUV imaging exposure of cluster #12 is taken using ACCUM. The first visit consists of TIME-TAG exposures with G130M/1291 (FP-POS 3, 4) for 4 orbits and the second visit with G160M/1600 (FP-POS=1, 2, 3, 4) for another 4 orbits. The exposure times are calculated to 16045( 2) - 05-Dec-2019 21:34:11 - [ 2] provide a S/N of 8 using WFC3/F275W=17.82, a SSP of 5 Myr and E(B-V)=0.28. ------------------------------------------------------------------------------------ 16045( 2) - 05-Dec-2019 21:34:11 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC5253-CLUS STELLAR CLUSTER, STAR RA-OFF=-2.153S, DEC-OFF=-3.289", J2000 V = 17.9 F275W=17.82 TER-12 FORMING REGION FROM 2 Extended: NO ------------------------------------------------------------------------------------------------------------------------------------ 2 OFFSET-STAR STAR, UNDESIGNATED RA=13H39M58.2760S +/- 0.05", J2000 V = 19.58 WFC3/UVIS F275W mag = 19.07 DEC=-31D38'19.78" +/- 0.05" Reference Frame: ICRS Extended: NO Comments: Coords are from Gaia DR2. Quoted V mag is GAIA G band mag which is close to Johnson V. ------------------------------------------------------------------------------------------------------------------------------------ 16045( 2) - 05-Dec-2019 21:34:11 - [ 4] Visit: 01 (Cluster 12-G130M) 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 OFFSET-STAR COS/NUV ACQ/IMA PSA MIRRORA 1 13.0 S (13 GE S) Comments: Used F275W mag and O5V SED with E(B-V)=0 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5253-CLU COS/NUV ACCUM PSA MIRRORA 1 18.0 S (18 STER-12 S) Comments: Used F275W mag =17.82, SSP 5 Myr SED with E(B-V)=0.28. NUV image of cluster and surrounding field. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5253-CLU COS/FUV TIME-TA PSA G130M 1291 FLASH=YES, FP-POS=3, 1 1114 S STER-12 G BUFFER-TIME=5016 (1114 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5253-CLU COS/FUV TIME-TA PSA G130M 1291 FLASH=YES, FP-POS=3, 1 1123 S STER-12 G BUFFER-TIME=5016 (1123 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5253-CLU COS/FUV TIME-TA PSA G130M 1291 FLASH=YES, FP-POS=4, 1 1347 S STER-12 G BUFFER-TIME=5016 (1347 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC5253-CLU COS/FUV TIME-TA PSA G130M 1291 FLASH=YES, FP-POS=4, 1 1346 S STER-12 G BUFFER-TIME=5016 (1346 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC5253-CLU COS/FUV TIME-TA PSA G130M 1291 FLASH=YES, FP-POS=3, 1 1347 S STER-12 G BUFFER-TIME=5016 (1347 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC5253-CLU COS/FUV TIME-TA PSA G130M 1291 FLASH=YES, FP-POS=3, 1 1346 S STER-12 G BUFFER-TIME=5016 (1346 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC5253-CLU COS/FUV TIME-TA PSA G130M 1291 FLASH=YES, FP-POS=4, 1 1347 S STER-12 G BUFFER-TIME=5016 (1347 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC5253-CLU COS/FUV TIME-TA PSA G130M 1291 FLASH=YES, FP-POS=4, 1 1346 S STER-12 G BUFFER-TIME=5016 (1346 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 | ------------------------------------------------------------------------------------------------------------------------------------ OFFSET-STAR 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE 16045( 2) - 05-Dec-2019 21:34:11 - [ 5] 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC5253-CLUSTER-12 2 COS/NUV ACCUM PSA MIRRORA none none none none 1 N/A NGC5253-CLUSTER-12 3 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G NGC5253-CLUSTER-12 4 COS/FUV TIME-TA PSA G130M 1291 none none none none 1 N/A G NGC5253-CLUSTER-12 5 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A G NGC5253-CLUSTER-12 6 COS/FUV TIME-TA PSA G130M 1291 none none none none 2 N/A G NGC5253-CLUSTER-12 7 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G NGC5253-CLUSTER-12 8 COS/FUV TIME-TA PSA G130M 1291 none none none none 3 N/A G NGC5253-CLUSTER-12 9 COS/FUV TIME-TA PSA G130M 1291 none none none none 4 N/A G NGC5253-CLUSTER-12 10 COS/FUV TIME-TA PSA G130M 1291 none none none none 4 N/A G 16045( 2) - 05-Dec-2019 21:34:11 - [ 6] Visit: 02 (Cluster 12-G160M) 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 OFFSET-STAR COS/NUV ACQ/IMA PSA MIRRORA 1 13.0 S (13 GE S) Comments: Used F275W mag and O5V SED with E(B-V)=0 ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC5253-CLU COS/NUV ACCUM PSA MIRRORA 1 18.0 S (18 STER-12 S) Comments: Used F275W mag =17.82, SSP 5 Myr SED with E(B-V)=0.28. NUV image of cluster and surrounding field. ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC5253-CLU COS/FUV TIME-TA PSA G160M 1600 FLASH=YES, FP-POS=1, 1 1100 S STER-12 G BUFFER-TIME=17944 (1100 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 NGC5253-CLU COS/FUV TIME-TA PSA G160M 1600 FLASH=YES, FP-POS=1, 1 1100 S STER-12 G BUFFER-TIME=17944 (1100 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 NGC5253-CLU COS/FUV TIME-TA PSA G160M 1600 FLASH=YES, FP-POS=2, 1 1356 S STER-12 G BUFFER-TIME=17944 (1356 S) ------------------------------------------------------------------------------------------------------------------------------------ 6 NGC5253-CLU COS/FUV TIME-TA PSA G160M 1600 FLASH=YES, FP-POS=2, 1 1356 S STER-12 G BUFFER-TIME=17944 (1356 S) ------------------------------------------------------------------------------------------------------------------------------------ 7 NGC5253-CLU COS/FUV TIME-TA PSA G160M 1600 FLASH=YES, FP-POS=3, 1 1356 S STER-12 G BUFFER-TIME=17944 (1356 S) ------------------------------------------------------------------------------------------------------------------------------------ 8 NGC5253-CLU COS/FUV TIME-TA PSA G160M 1600 FLASH=YES, FP-POS=3, 1 1356 S STER-12 G BUFFER-TIME=17944 (1356 S) ------------------------------------------------------------------------------------------------------------------------------------ 9 NGC5253-CLU COS/FUV TIME-TA PSA G160M 1600 FLASH=YES, FP-POS=4, 1 1356 S STER-12 G BUFFER-TIME=17944 (1356 S) ------------------------------------------------------------------------------------------------------------------------------------ 10 NGC5253-CLU COS/FUV TIME-TA PSA G160M 1600 FLASH=YES, FP-POS=4, 1 1356 S STER-12 G BUFFER-TIME=17944 (1356 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 | ------------------------------------------------------------------------------------------------------------------------------------ OFFSET-STAR 1 COS/NUV ACQ/IMA PSA MIRRORA none none none none 1 N/A GE 16045( 2) - 05-Dec-2019 21:34:11 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC5253-CLUSTER-12 2 COS/NUV ACCUM PSA MIRRORA none none none none 1 N/A NGC5253-CLUSTER-12 3 COS/FUV TIME-TA PSA G160M 1600 none none none none 1 N/A G NGC5253-CLUSTER-12 4 COS/FUV TIME-TA PSA G160M 1600 none none none none 1 N/A G NGC5253-CLUSTER-12 5 COS/FUV TIME-TA PSA G160M 1600 none none none none 2 N/A G NGC5253-CLUSTER-12 6 COS/FUV TIME-TA PSA G160M 1600 none none none none 2 N/A G NGC5253-CLUSTER-12 7 COS/FUV TIME-TA PSA G160M 1600 none none none none 3 N/A G NGC5253-CLUSTER-12 8 COS/FUV TIME-TA PSA G160M 1600 none none none none 3 N/A G NGC5253-CLUSTER-12 9 COS/FUV TIME-TA PSA G160M 1600 none none none none 4 N/A G NGC5253-CLUSTER-12 10 COS/FUV TIME-TA PSA G160M 1600 none none none none 4 N/A G 16045( 2) - 05-Dec-2019 21:34:11 - [ 8] Summary Form for Proposal 16045 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=17944, BUFFER-TIME=5016, FLASH=YES, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, G160M, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC5253-CLUSTER-12, OFFSET-STAR ------------------------------------------------------------------------------------------------------------------------------------