14723( 2) - 15-Jul-2016 17:50:20 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14723 Version: 2 Check-in Time: 15-Jul-2016 17:50:20 STScI Edit Number: 0 Title What controls the onset of the multiple population phenomenon within globular clusters? ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Emanuele Dalessandro Universita di Bologna Y CoI: Dr. Nate Bastian Liverpool John Moores University N CoI: Dr. Carmela Lardo Liverpool John Moores University N CoI: Dr. Alessio Mucciarelli Universita di Bologna N CoI: Mr. Mario Cadelano Universita di Bologna N ------------------------------------------------------------------------------------ Abstract The origin of the multiple populations (MPs) seen in nearly all globular clusters (GCs) is still unknown, with all suggested scenarios having serious shortcomings. While large ground based spectroscopic samples and space based imaging surveys have provided a wealth of data and shown how complex the situation is, they have not been able to pinpoint the GC property that controls whether MPs are present. GC mass is traditionally the assumed dominant factor, but recent results suggest a more complex scenario where the mass cannot be the only parameter. Hence, in order to make progress we need to understand which objects (if any) do not host MPs, and ultimately which property is responsible for the onset of MPs. Here we target two GCs that have been suggested to not host MPs (based on ground based imaging or abundance analyses of small stellar samples), Ruprecht 106 and IC 4499. These two clusters are "typical" in terms of age and mass of GCs, which would make the lack of MPs all the more surprising, if confirmed. If so, more exotic properties may have played a role (i.e., the type of galaxy where the clusters formed). ------------------------------------------------------------------------------------ Observations Description ------------------------ We request 8 exposures of ~1100sec in F275W, 4 exposures of 650sec in F336W and 4 exposures of ~100sec in F438W for a total of 4 orbits to sample the central regions of the Galactic globular cluster IC4499. In order to fully exploit the resolution and photometric accuracy of HST we applied properly defined offsets and post-flash operation to limit the charge-transfer efficiency (CTE) losses. ------------------------------------------------------------------------------------ 14723( 2) - 15-Jul-2016 17:50:20 - [ 2] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 IC4499 STELLAR CLUSTER, RA=15H00M13.0750S, J2000 V = 8.56 GLOBULAR CLUSTER DEC=-82D12'47.79" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 14723( 2) - 15-Jul-2016 17:50:20 - [ 3] Visit: 01 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 IC4499 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 97 S (97 POS TARG -10.0066, S ER S) -10.0066 ------------------------------------------------------------------------------------------------------------------------------------ 2 IC4499 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=12 1 1078 S POS TARG -10.0066, S ER (1078 S) -10.0066 ------------------------------------------------------------------------------------------------------------------------------------ 3 IC4499 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=12 1 985 S (985 POS TARG -12.5066, S ER S) -12.5066 ------------------------------------------------------------------------------------------------------------------------------------ 4 IC4499 WFC3/UVI ACCUM UVIS-CENT F336W FLASH=12 1 650 S (650 POS TARG -12.5066, S ER S) -12.5066 ------------------------------------------------------------------------------------------------------------------------------------ 5 IC4499 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 97 S (97 POS TARG -5.0132, S ER S) -5.0132 ------------------------------------------------------------------------------------------------------------------------------------ 6 IC4499 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=12 1 1087 S POS TARG -5.0132, S ER (1087 S) -5.0132 ------------------------------------------------------------------------------------------------------------------------------------ 7 IC4499 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=12 1 1087 S POS TARG -7.5132, S ER (1087 S) -7.5132 ------------------------------------------------------------------------------------------------------------------------------------ 8 IC4499 WFC3/UVI ACCUM UVIS-CENT F336W FLASH=12 1 650 S (650 POS TARG -7.5132, S ER S) -7.5132 ------------------------------------------------------------------------------------------------------------------------------------ 9 IC4499 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 97 S (97 POS TARG 0.0199, 0.0199 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 10 IC4499 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=12 1 1087 S POS TARG 0.0199, 0.0199 S ER (1087 S) ------------------------------------------------------------------------------------------------------------------------------------ 11 IC4499 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=12 1 1087 S POS TARG -2.4801, S ER (1087 S) -2.4801 ------------------------------------------------------------------------------------------------------------------------------------ 12 IC4499 WFC3/UVI ACCUM UVIS-CENT F336W FLASH=12 1 650 S (650 POS TARG -2.4801, S ER S) -2.4801 ------------------------------------------------------------------------------------------------------------------------------------ 13 IC4499 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=12 1 97 S (97 POS TARG 5.0265, 5.0265 S ER S) ------------------------------------------------------------------------------------------------------------------------------------ 14 IC4499 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=12 1 1087 S POS TARG 5.0265, 5.0265 S ER (1087 S) ------------------------------------------------------------------------------------------------------------------------------------ 14723( 2) - 15-Jul-2016 17:50:20 - [ 4] Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 15 IC4499 WFC3/UVI ACCUM UVIS-CENT F275W FLASH=12 1 1087 S POS TARG 2.5265, 2.5265 S ER (1087 S) ------------------------------------------------------------------------------------------------------------------------------------ 16 IC4499 WFC3/UVI ACCUM UVIS-CENT F336W FLASH=12 1 650 S (650 POS TARG 2.5265, 2.5265 S ER 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 | ------------------------------------------------------------------------------------------------------------------------------------ IC4499 1 WFC3/UVI ACCUM UVIS-CEN F438W none none none none 1 N/A S TER IC4499 2 WFC3/UVI ACCUM UVIS-CEN F275W none none none none 1 N/A S TER IC4499 3 WFC3/UVI ACCUM UVIS-CEN F275W none none none none 1 N/A S TER IC4499 4 WFC3/UVI ACCUM UVIS-CEN F336W none none none none 1 N/A S TER IC4499 5 WFC3/UVI ACCUM UVIS-CEN F438W none none none none 2 N/A S TER IC4499 6 WFC3/UVI ACCUM UVIS-CEN F275W none none none none 2 N/A S TER IC4499 7 WFC3/UVI ACCUM UVIS-CEN F275W none none none none 2 N/A S TER IC4499 8 WFC3/UVI ACCUM UVIS-CEN F336W none none none none 2 N/A S TER IC4499 9 WFC3/UVI ACCUM UVIS-CEN F438W none none none none 3 N/A S TER IC4499 10 WFC3/UVI ACCUM UVIS-CEN F275W none none none none 3 N/A S TER IC4499 11 WFC3/UVI ACCUM UVIS-CEN F275W none none none none 3 N/A S TER IC4499 12 WFC3/UVI ACCUM UVIS-CEN F336W none none none none 3 N/A S TER IC4499 13 WFC3/UVI ACCUM UVIS-CEN F438W none none none none 4 N/A S TER IC4499 14 WFC3/UVI ACCUM UVIS-CEN F275W none none none none 4 N/A S TER IC4499 15 WFC3/UVI ACCUM UVIS-CEN F275W none none none none 4 N/A S TER IC4499 16 WFC3/UVI ACCUM UVIS-CEN F336W none none none none 4 N/A S TER 14723( 2) - 15-Jul-2016 17:50:20 - [ 5] Summary Form for Proposal 14723 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=12 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements POS TARG -10.0066, -10.0066, POS TARG -12.5066, -12.5066, POS TARG -2.4801, -2.4801, POS TARG -5.0132, -5.0132, POS TARG -7.5132, -7.5132, POS TARG 0.0199, 0.0199, POS TARG 2.5265, 2.5265, POS TARG 5.0265, 5.0265 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F275W, F336W, F438W ------------------------------------------------------------------------------------------------------------------------------------ Target Names IC4499 ------------------------------------------------------------------------------------------------------------------------------------