0 Assigned ID: 741 ----- Attempting Submission 1 (Fri Apr 08 19:47:57 GMT 2016) ----- 0 ----- Attempting Submission 1 (Fri Jul 15 14:45:18 GMT 2016) ----- ----- Attempting Submission 2 (Tue Jul 19 14:34:45 GMT 2016) ----- Proper Motions of the Crater-Leo Group: Testing the Group Infall Scenario While substantial progress has been made in studying the dynamical properties of individual Milky Way (MW) satellites, groups of satellites have gained much interests only recently although such groups have long been predicted by cosmological simulations. Testing the picture of group infall requires the identification of candidate systems and measurement of their full 6D phase-space coordinates to assess the validity of a common orbital history. The Crater-Leo group of MW satellites (Crater 1/2, Leo II, IV, and V) constitute the best such candidates. Their numbers, positions, distances, line-of-sight velocities, and star formation histories (SFHs) are all indicative of a common origin. However, proper motion (PM) is the one key ingredient missing to study these valuable objects in great detail. Leo II has existing multi-epoch data in the archive and Leo IV will soon have PMs from our ongoing HST program. We propose to measure the PMs of the other 3 objects that belong to the Crater-Leo Group: Crater 1/2 and Leo V. These PMs will allow us to definitively confirm or rule out associations. There is a high chance that our measurements will identify the first known group of low-mass MW satellites, a key milestone towards ratifying LCDM theory. This finding will revolutionize research in near field cosmology by allowing to study the formation histories of dwarf galaxy having originated from, and interacted with, the same group environment. Regardless of the outcome, the newly defined orbits of these systems will furthermore place powerful constraints on the potential of the MW halo at distances where few probes exist. In Cycle 24, we will obtain first-epoch images for the two galaxies Crater 2 and Leo V. The deep F606W and F814W observations will allow us to create astrometric/photometric catalogs, construct CMDs, and study SFHs of the target galaxies in detail. The final goal of this program is to measure absolute proper motions for 3 target objects: globular cluster Crater 1, and dwarf galaxies Crater 2 and Leo V. In the current Cycle 24 program (GO-14770), we will obtain first-epoch data for Crater 2 and Leo V. We will observe these two galaxies using F606W and F814W filters to construct color-magnitude diagrams that allow (1) detailed study of their star formation histories and (2) selection of member stars to be used for proper motion measurements. Each galaxy will be observed for 2 orbits in F606W, and 2 orbits in F814W. Each orbit will be split into one short and two long exposures. Individual exposures will be dithered via POSTARG following a customized dithered pattern . To maximize the time baseline between this first-epoch and future (Cycle 26) second-epoch observations, we added Timing Requirements for all visits. We have also added Group requirements for each galaxy so that these visits can be treated as single epoch data for astrometric analysis. For Leo V, we also added Orientation Requirements to place the parallel WFC3/UVIS field near the semi-major axis of this galaxy. Stellar Populations Galaxies 0 false false false false false false SUPPORTED GALAXY DWARF ELLIPTICAL HALO J2000 J2000 GALAXY DWARF SPHEROIDAL HALO J2000 J2000 ACS/WFC Imaging No No F606W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F814W ACS/WFC Imaging No No F606W ACS/WFC Imaging No No F814W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F814W ACS/WFC Imaging No No F606W ACS/WFC Imaging No No F814W WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F814W Timing link suitability includes constraints ([Group (01 02) Within 15.0 days]) The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. This is the first visit for galaxy Crater 2. In this visit, we will image Crater 2 using the F606W filter for both primiary ACS/WFC and parallel WFC3/UVIS observations. Two orbits are required to complete this visit. Each orbit will consist of one short and two long exposures. To maximize the time baseline between this first-epoch and future (Cycle 26) second-epoch observations, we added Timing Requirements of "Before 01-FEB-2017" for this visit. This will ensure that our first-epoch observations are carried as early as possible. We have also added Group requirements of "within 15 days" for visits 01 and 02, so that these visits can be treated as single epoch data for astrometric analysis. (Tic-Visit :proposal-id 14770 :visit-id "01" :proposal-version -1 :trans-version "20160601" :date "14-Jul-2016 16:15:53.0" :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 20.0 :data-volume 3437808 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14770 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14770 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2888 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3221 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14770 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2999 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3221 :pcs-gap 0 ) true 2 0 Timing link suitability includes constraints ([Group (01 02) Within 15.0 days]) The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. This is the second visit for galaxy Crater 2. In this visit, we will image Crater 2 using the F814W filter for both primiary ACS/WFC and parallel WFC3/UVIS observations. Two orbits are required to complete this visit. Each orbit will consist of one short and two long exposures. To maximize the time baseline between this first-epoch and future (Cycle 26) second-epoch observations, we added Timing Requirements of "Before 01-FEB-2017" for this visit. This will ensure that our first-epoch observations are carried as early as possible. We have also added Group requirements of "within 15 days" for visits 01 and 02, so that these visits can be treated as single epoch data for astrometric analysis. (Tic-Visit :proposal-id 14770 :visit-id "02" :proposal-version -1 :trans-version "20160601" :date "14-Jul-2016 17:24:51.0" :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 20.0 :data-volume 3437808 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14770 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14770 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2888 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3221 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14770 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2999 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3221 :pcs-gap 0 ) true 2 0 Timing link suitability includes constraints ([Group (03 04) Within 15.0 days]) The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. This is the first visit for galaxy LeoV. In this visit, we will image Leo V using the F606W filter for both primiary ACS/WFC and parallel WFC3/UVIS observations. Two orbits are required to complete this visit. Each orbit will consist of one short and two long exposures. To maximize the time baseline between this first-epoch and future (Cycle 26) second-epoch observations, we added Timing Requirements of "Before 01-MAY-2017" for this visit. This will ensure that our first-epoch observations are carried as early as possible. We have added Group requirements of "within 15 days" for visits 03 and 04, so that these visits can be treated as single epoch data for astrometric analysis. We also added Orientation Requirements to place the parallel WFC3/UVIS field along the semi-major axis of Leo V. The Schedulability was accordingly reduced to 80. (Tic-Visit :proposal-id 14770 :visit-id "03" :proposal-version -1 :trans-version "20160601" :date "15-Jul-2016 10:25:42.0" :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 20.0 :data-volume 3437808 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14770 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14770 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2702 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3035 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14770 :visit-id "03" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2813 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3035 :pcs-gap 0 ) true 2 0 Timing link suitability includes constraints ([Group (03 04) Within 15.0 days]) The scheduling data was generated by CASM 24.2. CASM was run in Phase II mode. This is the second visit for galaxy LeoV. In this visit, we will image Leo V using the F814W filter for both primiary ACS/WFC and parallel WFC3/UVIS observations. Two orbits are required to complete this visit. Each orbit will consist of one short and two long exposures. To maximize the time baseline between this first-epoch and future (Cycle 26) second-epoch observations, we added Timing Requirements of "Before 01-MAY-2017" for this visit. This will ensure that our first-epoch observations are carried as early as possible. We have added Group requirements of "within 15 days" for visits 03 and 04, so that these visits can be treated as single epoch data for astrometric analysis. We also added Orientation Requirements of "Same Orient As Visit 03". The Schedulability was accordingly reduced to 80. (Tic-Visit :proposal-id 14770 :visit-id "04" :proposal-version -1 :trans-version "20160601" :date "14-Jul-2016 17:22:38.0" :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 20.0 :data-volume 3437824 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 14770 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 14770 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2702 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3035 :pcs-gap 0 ) (Tic-Orbit :proposal-id 14770 :visit-id "04" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2813 :al-overhead-at-end 0 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3035 :pcs-gap 0 ) true 2 0