Revision of phase 2. Changes: i) Added orient preference 148-154 degrees for both visits. ii) Added POS TARG (17,0) for both primary exposures in visit 01, and (11,-1) for both primary exposures in visit 02. ----- Attempting Submission 1 (Thu Sep 30 00:06:37 GMT 2010) ----- ----- Attempting Submission 2 (Mon Mar 14 22:46:06 GMT 2011) ----- It is my understanding that the diagnostics are OK. I am using centre_pattern with a POS_TARG. The pattern is a dither pattern that I want to be centred on the POS_TARG. Extreme Mergers from the Massive Cluster Survey We will observe an extraordinary, high-redshift galaxy cluster from the Massive Cluster Survey. The target is a very rare, triple merger system, and likely lies at the one of deepest nodes of the cosmic web. The target shows multiple strong gravitational lensing arcs in the cluster core. This target only possesses a very short (10ks) Chandra observations, and is unobserved by XMM-Newton. The X-ray data from this joint Chandra/HST proposal will be used to probe the mass distribution of hot, baryonic gas, and to reveal the details of the merger physics and the process of cluster assembly. We will also search for hints of X-ray emission from filaments between the merging clumps. Subaru and some Hubble Space Telescope imaging data are in hand; we will gather additional HST coverage for a lensing analysis.
The galaxy cluster MACS J1226 consists of three merging sub-clumps. The two main clumps (NE and S) each possess strong gravitational lensing arcs. We will observe these two main clumps with two separate pointings. Our aim is a combined strong and weak gravitational lensing analysis. The prime instrument will be ACS, with WFC3 operating in coordinated parallel mode for increased spatial coverage of this significantly extended galaxy cluster. Each pointing will consist of two orbits, one in F606W and one in F814W. The LOW SKY condition is required to allow a weak lensing analysis (this needs accurate shape measurements of faint background galaxies and hence the lowest possible instrumental background). The time required to dump the ACS and WFC3 buffers makes it impossible to obtain more than three equal length exposures in any one orbit. Since we prefer to use more than 3 dither positions for effective removal of cosmic rays etc, the exposures are of non-equal length so that it is possible to fit 4 of them into each orbit. There are fairly bright stars at i) 12 26 46.17, +21 48 50.57; and ii) 12 26 38.81, +21 47 21.13. The latter is of unknown magnitude in BOT but is clearly visible as a bright object in our existing ground-based Subaru data. Depending on the roll angle with which the observations are performed, these stars could potentially impact the quality of science data from the ACS exposure of the S clump (star i) and both parallel WFC3 observations (star ii). It might therefore be advantageous to allow us to fine-tune the target positions (by of the order of 10 arc-seconds) and/or the precise roll angle once the observations are scheduled and the range of allowed roll angles is known. Because these sources are highly extended, there is quite a wide range of acceptable target positions. This flexibility would also allow us to position the apertures to cover the largest possible fraction of the region of interest. (The system is much larger than the ACS field of view, but the W direction, towards the third sub-clump, is likely the most interesting direction.) 12 false 0.0 0.0 false false false false SUPPORTED CLUSTER OF GALAXIES GRAVITATIONAL LENS HIGH REDSHIFT CLUSTER J2000 12 26 51.5000 +21 51 15.50 J2000 CLUSTER OF GALAXIES GRAVITATIONAL LENS HIGH REDSHIFT CLUSTER J2000 12 26 51.5000 +21 51 15.50 J2000 WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F814W POS-TARG DITHER 3.011 LINE false true 4 85.28 ACS-WFC-DITHER-LINE 1 false /tmp/OPVisit5232870295274516556.xml The scheduling data was generated by CASM 19.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12368 :visit-id "01" :proposal-version -1 :trans-version "20100902" :date "14-Mar-2011 15:42:56.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 40.0 :data-volume 4583776 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12368 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12368 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2789 :al-overhead-at-end 85 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "Y" :pcs-visibility 3191 :pcs-gap 400 ) (Tic-Orbit :proposal-id 12368 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2780 :al-overhead-at-end 85 :internal-dur-at-end 1019 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "Y" :pcs-visibility 3191 :pcs-gap 400 ) true 2 0 /tmp/OPVisit5538146083174191727.xml The scheduling data was generated by CASM 19.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 12368 :visit-id "02" :proposal-version -1 :trans-version "20100902" :date "14-Mar-2011 15:43:39.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 40.0 :data-volume 4583776 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12368 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12368 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2789 :al-overhead-at-end 85 :internal-dur-at-end 670 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "Y" :pcs-visibility 3191 :pcs-gap 400 ) (Tic-Orbit :proposal-id 12368 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2780 :al-overhead-at-end 85 :internal-dur-at-end 1019 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "Y" :pcs-visibility 3191 :pcs-gap 400 ) true 2 0