12301( 4) - 07-Oct-2010 17:29:58 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12301 Version: 4 Check-in Time: 07-Oct-2010 17:29:58 STScI Edit Number: 0 Title Precision Age-Dating of Star Clusters in Stephan's Quintet ------------------------------------------------------------------------------------ Type Cycle GO 18 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Sarah Gallagher University of Western Ontario CoI: Mr. Konstantin Fedotov University of Western Ontario N CoI: Dr. Rupali Chandar University of Toledo N CoI: Dr. Iraklis Konstantopoulos The Pennsylvania State University N CoI: Dr. Nate Bastian University of Exeter N CoI: Dr. Brad C. Whitmore Space Telescope Science Institute N CoI: Dr. Philip N. Appleton NASA Herschel Science Center, Caltech N CoI: Prof. Jane C. Charlton The Pennsylvania State University N CoI: Dr. Linda J. Smith Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract The compact galaxy group Stephan's Quintet, showcased in the Early Release Observations of the newly refurbished Hubble, has experienced a complex series of gravitational interactions culminating in a ~50 kpc-long strong shock from the intruder NGC 7318B ploughing into NGC 7318A and the intragroup medium. Each major event within the past 500 Myrs has triggered star formation as demonstrated by the populations of massive star clusters present. Within this single system, we have the opportunity to study star-formation in novel settings not otherwise accessible in the nearby universe. We propose to make the most of this chance by supplementing the multi-color WFC3 images of Stephan's Quintet with 8 additional orbits of WFC3 imaging to obtain critical F336W (necessary for breaking the age-reddening degeneracy) and F547M (replacing F606W observations that are badly polluted by strong emission lines) observations. The combination of broad and narrow-band photometry will enable unprecedented precision in obtaining ages and masses for the <500 Myr-old star clusters within this system. With this information in hand, these clusters can be used as tracers of the gross galaxy interactions over time, and probes of the physics of star formation within the large-scale shock in particular. ------------------------------------------------------------------------------------ Observations Description ------------------------ We plan to have 6 orbits with F336W filter and 2 orbits with F547M filter. For each orbit we use WFC3-UVIS-MOS-DITH-LINE pattern (with 3 point secondary pattern for dithering separated by 0.119 arcsec), which will provide good sampling of the PSF, as well as minimize the readout noise. In the first visit, which consists of 5 orbits (all with F336W filter), we use 5 primary dither pointings. Each primary point is separated by 2.4 arcsec in order to cover the gap between the CCDs. In the second visit we have one orbit with F336W filter and 2 orbits with F547M filter. For the first orbit of the second visit we use WFC3-UVIS-MOS-DITH-LINE pattern with 3 point primary pattern separated by 2.4 arcsec in order to cover the interchip gap but no secondary pattern. For the last two orbits we use same pattern with 3 secondary dither pointings separated 12301( 4) - 07-Oct-2010 17:29:58 - [ 2] by 0.119 arcsec and 2 primary pointings, with the same separation as before. Real Time Justification ----------------------- Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 12301( 4) - 07-Oct-2010 17:29:58 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 HCG92 STELLAR CLUSTER, SHOCK RA=22H36M0.7161S +/- 0.1", J2000 V = 14.9 FRONT, STAR FORMING DEC=+33D57'40.96" +/- 0.1" REGION, TIDAL TAIL, YOUNG ASSOCIATION Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 12301( 4) - 07-Oct-2010 17:29:58 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-MOS-DITH-LINE Pattern_Purpose DITHER Number_Of_Points 2 Point_Spacing 2.4 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 85.754 Angle_Between_Sides Center_Pattern YES ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 3 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-MOS-DITH-LINE WFC3-UVIS-MOS-DITH-LINE Pattern_Purpose MOSAIC DITHER Number_Of_Points 5 2 Point_Spacing 2.4 0.119 Line_Spacing Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 85.754 33.606 Angle_Between_Sides Center_Pattern YES NO ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 4 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-MOS-DITH-LINE WFC3-UVIS-MOS-DITH-LINE Pattern_Purpose MOSAIC DITHER Number_Of_Points 2 2 Point_Spacing 2.4 0.119 Line_Spacing Coordinate_Frame POS-TARG POS-TARG Pattern_Orient 85.754 33.606 Angle_Between_Sides Center_Pattern YES NO ------------------------------------------------------------------------------------------------------------------------------------ 12301( 4) - 07-Oct-2010 17:29:58 - [ 5] Visit: 01 Visit Requirements: ORIENT 72D TO 82 D; ORIENT 252D TO 262 D On Hold Comments: Additional Comments: 5 orbits U(336) band Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HCG92 WFC3/UVI ACCUM UVIS-CENT F336W 1 892 S PATTERN 3 1 S ER see below ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 1 1 none none 1 1428.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 1 2 none none 1 1378.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 2 1 none none 2 1458.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 2 2 none none 2 1459.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 3 1 none none 3 1458.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 3 2 none none 3 1459.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 4 1 none none 4 1458.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 4 2 none none 4 1459.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 5 1 none none 5 1458.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 5 2 none none 5 1459.0 S S TER 12301( 4) - 07-Oct-2010 17:29:58 - [ 6] Visit: 02 Visit Requirements: SAME ORIENT AS 01 On Hold Comments: Additional Comments: 3 orbits: 1 of U(336) + 2 of V(547) band Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 HCG92 WFC3/UVI ACCUM UVIS-CENT F336W 1 637 S PATTERN 1 1 S ER see below ------------------------------------------------------------------------------------------------------------------------------------ 2 HCG92 WFC3/UVI ACCUM UVIS-CENT F547M 1 637 S PATTERN 4 2 S ER see below ------------------------------------------------------------------------------------------------------------------------------------ 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 | ------------------------------------------------------------------------------------------------------------------------------------ HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 1 none none none 1 1408.0 S S TER HCG92 1 WFC3/UVI ACCUM UVIS-CEN F336W 2 none none none 1 1398.0 S S TER HCG92 2 WFC3/UVI ACCUM UVIS-CEN F547M 1 1 none none 2 1459.0 S S TER HCG92 2 WFC3/UVI ACCUM UVIS-CEN F547M 1 2 none none 2 1458.0 S S TER HCG92 2 WFC3/UVI ACCUM UVIS-CEN F547M 2 1 none none 3 1458.0 S S TER HCG92 2 WFC3/UVI ACCUM UVIS-CEN F547M 2 2 none none 3 1459.0 S S TER 12301( 4) - 07-Oct-2010 17:29:58 - [ 7] Summary Form for Proposal 12301 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 252D TO 262 D, ORIENT 72D TO 82 D, PATTERN 1 1, PATTERN 3 1, PATTERN 4 2, SAME ORIENT AS 01 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W, F547M ------------------------------------------------------------------------------------------------------------------------------------ Target Names HCG92 ------------------------------------------------------------------------------------------------------------------------------------