12012( 2) - 23-Oct-2009 20:11:46 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 12012 Version: 2 Check-in Time: 23-Oct-2009 20:11:46 STScI Edit Number: 0 Title Binary Formation in the Sparse Galactic Globular Cluster NGC 3201 ------------------------------------------------------------------------------------ Type Cycle GO 17 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Gregory R. Sivakoff The University of Virginia CoI: Dr. Ryan Lynch The University of Virginia N CoI: Dr. Craig Heinke University of Alberta N CoI: Dr. Natasha Ivanova University of Alberta N CoI: Dr. Scott M. Ransom Associated Universities, Inc. N CoI: Dr. Craig L. Sarazin The University of Virginia N ------------------------------------------------------------------------------------ Abstract Bright X-ray sources in globular clusters, X-ray binaries, cataclysmic variables, active binaries, and millisecond pulsars, are all binary systems or thought to be the products of such systems. Studies of X-ray sources in GCs thus probe binary formation. Most past observations have concentrated on dense GCs; these systems show clear evidence for strong dynamical formation of binaries; however, sparse clusters seem to fall off this pattern. Potential explanantions include, among others, primordial binary formation and a misunderstanding of the dynamical state of some GCs. We propose an 85 ks ACIS-S observation of NGC~3201, the nearest sparse GC unobserved by Chandra to test these explanations. We request 1 orbit of HST to discriminate CVs from ABs, and 1 hour of GBT time to search for MSPs. ------------------------------------------------------------------------------------ Observations Description ------------------------ We request a single orbit of F435W (B) imaging with HST to provide B-V colors. We choose ACS for its high sensitivity. Thr orbit is packed with one short exposure to avoid saturation for giant stars below the red clump, four long exposures using a box dither designed to avoid saturation for stars below the main sequence turnover. We also add a second 405 F606W exposure (to double the existing data). We will reach approximately 8 magnitudes below the main sequence in B. This will match the depth in F606W for typical CV spectra (~A0), and would reach deep enough to identify the majority of CVs seen in 47 Tuc. Thus, these HST observations will significantly increase the utility of our proposed Chandra observations by allowing us to differentiate CVs from chromospherically active binaries. Real Time Justification ----------------------- Calibration Justification ------------------------- 12012( 2) - 23-Oct-2009 20:11:46 - [ 2] Additional Comments ------------------- If possible, we request an orientation and position that matches close to Datasets J9L946010/J9L946020 to maximize coverage when making color magnitude diagrams. ------------------------------------------------------------------------------------ 12012( 2) - 23-Oct-2009 20:11:46 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-3201 STELLAR CLUSTER, RA=10H17M36.7600S +/- 0.1", J2000 V = 8.24 GLOBULAR CLUSTER DEC=-46D24'40.40" +/- 0.1" Reference Frame: ICRS Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 12012( 2) - 23-Oct-2009 20:11:46 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.265 Line_Spacing 0.187 Coordinate_Frame POS-TARG Pattern_Orient 20.67 Angle_Between_Sides 69.05 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 12012( 2) - 23-Oct-2009 20:11:46 - [ 5] 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| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 NGC-3201 ACS/WFC ACCUM WFC F435W 1 30 S ------------------------------------------------------------------------------------------------------------------------------------ 2 NGC-3201 ACS/WFC ACCUM WFC F435W 1 360 S PATTERN 1 2 ------------------------------------------------------------------------------------------------------------------------------------ 3 NGC-3201 ACS/WFC ACCUM WFC F606W 1 405 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 | ------------------------------------------------------------------------------------------------------------------------------------ NGC-3201 1 ACS/WFC ACCUM WFC F435W none none none none 1 N/A NGC-3201 2 ACS/WFC ACCUM WFC F435W 1 none none none 1 N/A NGC-3201 2 ACS/WFC ACCUM WFC F435W 2 none none none 1 N/A NGC-3201 2 ACS/WFC ACCUM WFC F435W 3 none none none 1 N/A NGC-3201 2 ACS/WFC ACCUM WFC F435W 4 none none none 1 N/A NGC-3201 3 ACS/WFC ACCUM WFC F606W none none none none 1 N/A 12012( 2) - 23-Oct-2009 20:11:46 - [ 6] Summary Form for Proposal 12012 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures WFC ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements PATTERN 1 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F435W, F606W ------------------------------------------------------------------------------------------------------------------------------------ Target Names NGC-3201 ------------------------------------------------------------------------------------------------------------------------------------