It is a science requirement of the proposal that a given target be observed at the same U3 angle in cycles 17,18,19. To ensure this, we have specified ORIENT ranges that permit the longest windows in which observations can be scheduled according to APT. Proposal updated after experience with visit 03 -- spiral dither pattern changed, and 2 short exposures added with subarray to visits 01, 02 Visit 06 unchanged since it is scheduling and must be observed at the same orient as visit 03 ----- Attempting Submission 1 (Wed Jul 02 09:18:12 GMT 2008) ----- ----- Attempting Submission 2 (Mon Aug 17 21:44:46 GMT 2009) ----- ----- Attempting Submission 3 (Thu Jul 08 01:47:35 GMT 2010) ----- The diagnostics refer to visits03 and 06 not being schedulable. Visit03 has executed and we have made no changes to visit06. Assigned ID: 808 ----- Attempting Submission 1 (Sat Mar 08 00:00:27 GMT 2008) ----- Kinematic Reconstruction of the Origin and IMF of the Massive Young Clusters at the Galactic Center We propose to exploit the wide field capabilities of Wide Field Camera 3 to study star formation at the Galactic center. By studying young stars located in the most physically extreme region of our Galaxy, we can test star formation theories, which suggest that such environments should favor high mass stars and, in extreme cases, should suppress star formation entirely. Specifically, we will measure the proper motions and photometry of stars over the full extent of the three massive young clusters that have been identified at the Galactic Center (Arches, Quintuplet, and the Young Nuclear Star Cluster). These observations are a factor of ∼2000 more efficient than what can be done with ground-based adaptive optics. Our goals are two-fold. First, we hope to establish the initial sites of star formation in order to obtain an accurate estimate of the conditions that led to the stellar populations within these clusters. Answering this question for the Young Nuclear Star Cluster is particularly important as it establishes whether or not star formation can indeed proceed within 0.1 pc of our Galaxy’s supermassive black hole. Second, we will measure the IMF in the Arches and Quintuplet, where dynamical evolution is less severe, using proper motions to determine membership and to reveal the tidal radius. Probing how the properties of the emergent stellar populations within our Galaxy may be affected by the physical environment in which they arise is an important first step to understanding how they might vary as a function of cosmic time and thereby affect our models of galaxy formation and evolution.
Update July 2010 -- based on experience with visit 03, we now want to use patterns as per visit 3 and 6, but rotated to ensure more uniform pixel phase coverage. As visit 06 is scheduling and uses pattern 5 SPIRAL, we have made copies of the existing spiral patterns, changed the orientation of the patterns, and set visits 1,2,4,5 to use these patterns. So patterns change 2SPIRAL --> 6SPIRAL and 5SPIRAL --> 7SPIRAL. Experience with visit 03 also suggests that for some objects the brightest few pix can saturate in <10s. To provide finer sampling for the initial 10s for as many objects as possible, we add two exposures to the end of each of the final astrometric orbits with the 512x512 subarray and dither by (n+0.5, m+0.5) pix. This allows 11 samples for the first 10s and seven for the first 6s (compared to 3 and 2 for the same intervals in full-frame mode). Update August 2009 - ORIENT ranges specified. We need to observe at the same U3 angle in subsequent cycles, so we have selected the ORIENT values that give the broadest possible schedule windows (according to APT). Our experiments on the Arches, Quintuplet, and the Young Nuclear Star Cluster will be conducted with both astrometric and three-filter photometric measurements. The Galactic Center is optically obscured and the three clusters have a large (~100”) predicted spatial extent; therefore, all observations will be conducted with WFC3 in the near infrared. The specific requirements and exposure times for the astrometry and photometry are described below. Our group has significant experience in working with high precision astrometric and photometric data sets both in general and from HST. Astrometry: To achieve the required 1 mas astrometric precision with WFC3, it is important that the orientation and positioning of the fields of view are the same for our observations in all three HST cycles (17, 18, and 19). Additionally, we will improve the PSF sampling by using a spiral dither pattern that has sub-pixel steps. The total extent of the dither pattern is less than 20 pixels. These requirements are all necessary to reduce the effects of optical distortion; however, to achieve the most accurate astrometry, we must have a high quality optical distortion solution for the camera. Our science requires a distortion solution that yields residuals of <0.01 pixels (1 mas) in WFC3-IR. Members of our group have shown that this level of distortion correction is possible for under-sampled PSFs such as in WFC3. Distortion calibration to 0.005 pixels has been achieved with ACS and is also planned for WFC3 using similar techniques. To minimize the impact of any residual distortions, we request that the astrometric observations within each cluster have the SAME ORIENT with small POS TARG offsets in all three cycles. Our observations should reach at least a SNR ~100 for an H=20 star. Individual exposure times are limited by the effects of persistence from saturated sources, which can negatively impact astrometry and photometry. We chose a medium band filter for our astrometry rather than a wide filter in order to avoid saturating the brightest sources in the field (H=10) prior to the first detector read. Some saturated sources are inevitable since the brightest sources are H=10 in the Quintuplet and H=12 in the Arches. These sources will saturate in less than 3 s; however, the density of bright stars is low enough that hard-saturating all stars with H<15 (<100 stars in the 120” field of view) should produce persistence images with a low enough density that dithering can shift sources in subsequent exposures on to persistence-free portions of the detector. Saturated sources will be recoverable from the earliest reads of the up-the-ramp samples used by WFC3. The maximum possible exposure time to avoid persistence images from stars fainter than H=15 is ~350 s. Therefore, our H-band astrometric program will consist of a series of exposures with texp =349.2 to accommodate 12 MULTIACCUM readouts (STEP 50 readout pattern). Photometry: Photometry will be extracted from three medium band filters: F153M, F139M, and F127M to accurately construct extinction maps for all three clusters and mass functions for the Arches and Quintuplet. These measurements require reaching a SNR of ~35 at m_F139M ~ 21.5 and m_F127M ~ 23. Saturation considerations are similar to those described above and the optimal exposure times for the two filters are t_{exp,F139M} = 349 s and t_{exp,F127M} =600 s. Again to maximize sampling of the PSF, we choose sub-pixel steps for the dither patterns. In order to achieve the necessary astrometric precision, we need observations in cycle 17, 18, and 19 to be observed at the same roll angle. RESOLVED STELLAR POPULATIONS 12 false 0.0 0.0 false false false false false false SUPPORTED STELLAR CLUSTER NUCLEUS STAR FORMING REGION The V-magnitude is for the brightest optical star in the field of view. J=11.5, H=10.5, K=10.2 J2000 17 45 50.5000 -28 49 28.00 J2000 STELLAR CLUSTER NUCLEUS STAR FORMING REGION The fluxes are for the brightest star in the WFC3 field of view. The brightest optical star is different from the brightest near-infrared star. J=11.8, H=8.9, K=7.29 J2000 17 46 13.9000 -28 49 48.00 J2000 STELLAR CLUSTER NUCLEUS STAR FORMING REGION The fluxes are for the brightest star within the field-of-view for each filter. The brightest star is a different for all 4 filters. J=12.2, H=9.26, K=6.5 J2000 17 45 40.0400 -29 00 28.10 J2000 WFC3/IR Imaging No No F153M WFC3/IR Imaging No No F139M WFC3/IR Imaging No No F127M WFC3/IR Imaging No No F153M WFC3/IR Imaging No No F139M WFC3/IR Imaging No No F127M WFC3/IR Imaging No No F153M WFC3/IR Imaging No No F139M WFC3/IR Imaging No No F127M WFC3/IR Imaging No No F153M WFC3/IR Imaging No No F153M WFC3/IR Imaging No No F153M WFC3/IR Imaging No No F153M WFC3/IR Imaging No No F153M WFC3/IR Imaging No No F153M POS-TARG DITHER 0.572 LINE 0.365 false false 74.653 4 18.528 WFC3-IR-DITHER-BOX-MIN 1 false POS-TARG DITHER 0.42 LINE false false 21 0 SPIRAL 2 false POS-TARG DITHER 0.42 LINE false false 21 11.0 SPIRAL 6 false POS-TARG DITHER 0.42 LINE false false 7 0 SPIRAL 5 false POS-TARG DITHER 0.43 LINE false false 7 28.0 SPIRAL 7 false The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. /private/tmp/OPVisit5173290801272272664.xml === July 2010 - updated to use rotated spiral dither patterns. Two short exposures added. Arches Astrometry and F153M Photometry. We need to optimize the scheduling of these Cycle 17 observations such that it is easy to schedule Cycle 18 and 19 observations at the exact same orientation. August 2008 - To enable cycle18,19 observations to be scheduled at the same orientation as Cycle17, we specify ORIENT ranges that have the maximum interval of ORIENT availability that we were able to determine with APT. *NOTE* these ORIENTS are values within APT; correspondence with Tricia Royle indicates that the operational software returns different ORIENTS. We request confirmation of the intervals of availability for these ORIENT ranges in future cycles, if possible. (Tic-Visit :proposal-id 11671 :visit-id "01" :proposal-version -1 :trans-version "20100505" :date "07-Jul-2010 15:41:06.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 4898112 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11671 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11671 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3003 :al-overhead-at-end 0 :internal-dur-at-end 623 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. /private/tmp/OPVisit3199112965147063178.xml Arches F139M and F127M Photometry (Tic-Visit :proposal-id 11671 :visit-id "04" :proposal-version -1 :trans-version "20100505" :date "07-Jul-2010 15:42:06.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 4978912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11671 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11671 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "04" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "04" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 692 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 4 0 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. /private/tmp/OPVisit7496576641239072255.xml Quintuplet Astrometry and F153M Photometry. We need to optimize the scheduling of these Cycle 17 observations such that it is easy to schedule Cycle 18 and 19 observations at the exact same orientation. August 2008 - To enable cycle18,19 observations to be scheduled at the same orientation as Cycle17, we specify ORIENT ranges that have the maximum interval of ORIENT availability that we were able to determine with APT. *NOTE* these ORIENTS are values within APT; correspondence with Tricia Royle indicates that the operational software returns different ORIENTS. We request confirmation of the intervals of availability for these ORIENT ranges in future cycles, if possible. (Tic-Visit :proposal-id 11671 :visit-id "02" :proposal-version -1 :trans-version "20100505" :date "07-Jul-2010 15:43:15.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 4898112 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11671 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11671 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "02" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3003 :al-overhead-at-end 0 :internal-dur-at-end 623 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. /private/tmp/OPVisit8658049045183040873.xml Quintuplet F139M and F127M Photometry (Tic-Visit :proposal-id 11671 :visit-id "05" :proposal-version -1 :trans-version "20100505" :date "07-Jul-2010 15:44:20.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 4978912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11671 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11671 :visit-id "05" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "05" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "05" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "05" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 692 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 4 0 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. /Users/clarkson/Desktop/HST_phaseII_july2010/OP-cache/11671_redithered_shortatend_presubmit-v03.xml SgrA Astrometry and F153M Photometry. We need to optimize the scheduling of these Cycle 17 observations such that it is easy to schedule Cycle 18 and 19 observations at the exact same orientation. August 2008 - To enable cycle18,19 observations to be scheduled at the same orientation as Cycle17, we specify ORIENT ranges that have the maximum interval of ORIENT availability that we were able to determine with APT. *NOTE* these ORIENTS are values within APT; correspondence with Tricia Royle indicates that the operational software returns different ORIENTS. We request confirmation of the intervals of availability for these ORIENT ranges in future cycles, if possible. 1277794296000 90.0 (Tic-Visit :proposal-id 11671 :visit-id "03" :proposal-version -1 :trans-version "20100505" :date "14-Jul-2010 23:14:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 4752688 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11671 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11671 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "03" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 711 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 3 0 The scheduling data was generated by CASM 18.3.1. CASM was run in Phase II mode. /Users/clarkson/Desktop/HST_phaseII_july2010/OP-cache/11671_redithered_shortatend_presubmit-v06.xml SgrA F139M and F127M Photometry (Tic-Visit :proposal-id 11671 :visit-id "06" :proposal-version -1 :trans-version "20100505" :date "14-Jul-2010 23:15:33.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 4978912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 11671 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 11671 :visit-id "06" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2857 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "06" :orbit-number 2 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "06" :orbit-number 3 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) (Tic-Orbit :proposal-id 11671 :visit-id "06" :orbit-number 4 :pcs-time 222 :si-vis-utilization 3035 :al-overhead-at-end 0 :internal-dur-at-end 692 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3257 :pcs-gap 0 ) true 4 0