15114( 2) - 21-Jul-2017 15:03:24 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15114 Version: 2 Check-in Time: 21-Jul-2017 15:03:24 STScI Edit Number: 0 Title Star cluster formation in extreme environments: an isolated pair of closely interacting dwarf galaxies ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Ruben Sanchez-Janssen Royal Observatory Edinburgh Y CoI: Dr. Gabriel Brammer Space Telescope Science Institute - ESA N CoI: Dr. Ricardo Amorin University of Cambridge N CoI: Dr. Kristine Spekkens Royal Military College of Canada N CoI: Dr. Karen Lee-Waddell CSIRO, Australia Telescope National N Facility CoI: Dr. Angel Lopez-Sanchez Anglo-Australian Observatory N CoI: Dr. Jean-Michel Gomes Universidade do Porto N CoI: Dr. Polychronis Papaderos Universidade do Porto N ------------------------------------------------------------------------------------ Abstract We have identified a nearby pair of closely interacting dwarf galaxies that host a population of candidate young massive clusters (YMCs). The strong interaction has triggered nearly coeval galaxy-scale starbursts, with a delay time of only ~100 Myr from one galaxy to the other. It has also altered their stellar structure and content, as indicated by the presence of prominent tidal features, some of which host YMCs. Here we propose to carry out a UV-to-optical imaging survey of the system with WFC3/UVIS. We will take advantage of HST's unrivalled resolution and sensitivity to detect and characterize the star cluster population in each of the two interacting dwarf galaxies. The proposed multiband photometry will be instrumental to determine ages, masses and sizes of the YMCs, as well as to provide a robust characterization of the underlying host galaxy--thus allowing for an investigation of the cluster formation efficiency in a gas-rich, high-density, metal-poor environment very reminiscent of the existing conditions at high redshift. ------------------------------------------------------------------------------------ Observations Description ------------------------ This is a relatively simple imaging proposal of a pair of interacting dwarf galaxies hosting young star cluster candidates. We will observe the pair of galaxies with WFC3/UVIS in six filters: F275W, F336W, F438W, F606W, F657N, F814W. The two objects fit within a single WFC3 pointing provided the orientation is limited to a narrow range of angles (55-63deg), which we have specified. To improve the scheduling of the observations are split in two visits using blue and (mostly) red filters. We also ask for the second visit to be observed at exactly the same orient angle as the first one. Because in addition to the clusters we're looking for extended emission we use 15114( 2) - 21-Jul-2017 15:03:24 - [ 2] a gap-line dithering pattern for most filters (or individual offset exposures). ------------------------------------------------------------------------------------ 15114( 2) - 21-Jul-2017 15:03:24 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 UGC-05205 GALAXY, INTERACTING RA=09H44M3.8535S, J2000 V = 26 +/- 0.3 GALAXY DEC=-00D39'42.34" Reference Frame: Other: NED Comments: This object was generated by the targetselector and retrieved from the NED database. ------------------------------------------------------------------------------------------------------------------------------------ 15114( 2) - 21-Jul-2017 15:03:24 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-GAP-LINE Pattern_Purpose MOSAIC Number_Of_Points 2 Point_Spacing 2.414 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.759 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ 15114( 2) - 21-Jul-2017 15:03:24 - [ 5] Visit: 01 (Red filters) Visit Requirements: ORIENT 55D TO 63 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 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F657N FLASH=9 1 860 S (860 S S) ------------------------------------------------------------------------------------------------------------------------------------ 2 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F657N FLASH=9 1 860 S (860 POS TARG 1.12, -1.52 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F657N FLASH=9 1 860 S (860 POS TARG 2.24, 1.52 S S) ------------------------------------------------------------------------------------------------------------------------------------ 4 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F438W FLASH=9 1 370 S (370 S S) ------------------------------------------------------------------------------------------------------------------------------------ 5 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F606W 1 370 S (740 PATTERN 4 5-6 S S) ------------------------------------------------------------------------------------------------------------------------------------ 6 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F814W 1 625 S S (1250 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 | ------------------------------------------------------------------------------------------------------------------------------------ UGC-05205 1 WFC3/UVI ACCUM UVIS-FIX F657N none none none none 1 N/A S UGC-05205 2 WFC3/UVI ACCUM UVIS-FIX F657N none none none none 1 N/A S UGC-05205 3 WFC3/UVI ACCUM UVIS-FIX F657N none none none none 1 N/A S UGC-05205 4 WFC3/UVI ACCUM UVIS-FIX F438W none none none none 2 N/A S UGC-05205 5 WFC3/UVI ACCUM UVIS-FIX F606W 1 none none none 2 N/A S UGC-05205 5 WFC3/UVI ACCUM UVIS-FIX F606W 2 none none none 2 N/A S UGC-05205 6 WFC3/UVI ACCUM UVIS-FIX F814W 1 none none none 2 N/A S UGC-05205 6 WFC3/UVI ACCUM UVIS-FIX F814W 2 none none none 2 N/A S 15114( 2) - 21-Jul-2017 15:03:24 - [ 6] Visit: 02 (Blue filters) Visit Requirements: SAME ORIENT AS 01 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 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F336W FLASH=9 1 860 S (860 S S) ------------------------------------------------------------------------------------------------------------------------------------ 2 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F336W FLASH=9 1 860 S (860 POS TARG 1.12, -1.52 S S) ------------------------------------------------------------------------------------------------------------------------------------ 3 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F336W FLASH=9 1 860 S (860 POS TARG 2.24, 1.52 S S) ------------------------------------------------------------------------------------------------------------------------------------ 4 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F275W FLASH=9 1 900 S (900 S S) ------------------------------------------------------------------------------------------------------------------------------------ 5 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F275W FLASH=9 1 900 S (900 POS TARG 1.12, -1.52 S S) ------------------------------------------------------------------------------------------------------------------------------------ 6 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F275W FLASH=9 1 900 S (900 POS TARG 2.24, 1.52 S S) ------------------------------------------------------------------------------------------------------------------------------------ 7 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F275W FLASH=9 1 900 S (900 S S) ------------------------------------------------------------------------------------------------------------------------------------ 8 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F275W FLASH=9 1 900 S (900 POS TARG 1.12, -1.52 S S) ------------------------------------------------------------------------------------------------------------------------------------ 9 UGC-05205 WFC3/UVI ACCUM UVIS-FIX F438W FLASH=9 1 370 S (740 PATTERN 4 9 S 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 | ------------------------------------------------------------------------------------------------------------------------------------ UGC-05205 1 WFC3/UVI ACCUM UVIS-FIX F336W none none none none 1 N/A S UGC-05205 2 WFC3/UVI ACCUM UVIS-FIX F336W none none none none 1 N/A S UGC-05205 3 WFC3/UVI ACCUM UVIS-FIX F336W none none none none 1 N/A S UGC-05205 4 WFC3/UVI ACCUM UVIS-FIX F275W none none none none 2 N/A S 15114( 2) - 21-Jul-2017 15:03:24 - [ 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 | ------------------------------------------------------------------------------------------------------------------------------------ UGC-05205 5 WFC3/UVI ACCUM UVIS-FIX F275W none none none none 2 N/A S UGC-05205 6 WFC3/UVI ACCUM UVIS-FIX F275W none none none none 2 N/A S UGC-05205 7 WFC3/UVI ACCUM UVIS-FIX F275W none none none none 3 N/A S UGC-05205 8 WFC3/UVI ACCUM UVIS-FIX F275W none none none none 3 N/A S UGC-05205 9 WFC3/UVI ACCUM UVIS-FIX F438W 1 none none none 3 N/A S UGC-05205 9 WFC3/UVI ACCUM UVIS-FIX F438W 2 none none none 3 N/A S 15114( 2) - 21-Jul-2017 15:03:24 - [ 8] Summary Form for Proposal 15114 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=9 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 55D TO 63 D, PATTERN 4 5-6, PATTERN 4 9, POS TARG 1.12, -1.52, POS TARG 2.24, 1.52, SAME ORIENT AS 01 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F275W, F336W, F438W, F606W, F657N, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names UGC-05205 ------------------------------------------------------------------------------------------------------------------------------------