14643( 3) - 08-Jul-2016 12:52:34 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14643 Version: 3 Check-in Time: 08-Jul-2016 12:52:34 STScI Edit Number: 1 Title Imaging of three Ultra Diffuse Galaxies with measured stellar kinematics ------------------------------------------------------------------------------------ Type Cycle GO 24 ------------------------------------------------------------------------------------ Investigators Contact? PI: Prof. Pieter van Dokkum Yale University Y CoI: Dr. Roberto G. Abraham University of Toronto N CoI: Prof. Aaron Romanowsky San Jose State University N CoI: Prof. Jean P. Brodie University of California - Santa Cruz N CoI: Prof. Charlie Conroy Harvard University N CoI: Allison Merritt Yale University N CoI: Lamiya Mowla Yale University N CoI: Mrs. Shany Danieli Yale University N ------------------------------------------------------------------------------------ Abstract In 2015 we discovered a new population of galaxies. Initially found in the Coma cluster, "Ultra Diffuse Galaxies", or UDGs, have the sizes of Milky Way-like galaxies but the luminosities of dwarf galaxies. We recently succeeded in measuring the absorption line kinematics of three Coma UDGs, using 20 hr integrations with DEIMOS on the Keck telescope. Surprisingly, the velocity dispersions of the galaxies span a large range, from ~20 km/s to ~80 km/s. The most straightforward interpretation is that UDGs span a very large range in dynamical mass, with the most massive UDGs having halos masses similar to that of the Milky Way. Here we propose to test this using deep HST imaging of the three UDGs with velocity dispersion measurements. The primary aim is to count their globular clusters: if the interpretation of the dispersions is correct, the galaxy with sigma=80 km/s should have ~10x more globular clusters than the galaxies with sigma=20-30 km/s. Secondary goals include an analysis of the central regions of the UDGs; a search for star forming regions; a measurement of the radial variation in ellipticity and position angle; and a search for faint satellites around them. With primary ACS/WFC and parallel WFC3/UVIS observations we can image all three UDGs with dynamical measurements, as well as a fourth spectroscopically confirmed Coma UDG, in two pointings. ------------------------------------------------------------------------------------ Observations Description ------------------------ The observations are split into 4 visits. Each visit consists of two orbits. Each orbit consists of 4 dithered exposures with ACS/WFC and WFC3/UVIS: visit 1: target DFX1+DFX2, 1 orbit F814W and 1 orbit F606W visit 2: target DFX1+DFX2, 2 orbits F606W visit 3: target DF42+DF44, 1 orbit F814W and 1 orbit F606W visit 4: target DF42+DF44, 2 orbits F606W A standard small box dither pattern is used. There is no need to dither over the ACS chip gap. 14643( 3) - 08-Jul-2016 12:52:34 - [ 2] The ORIENT constraints are necessary as two targets are observed simultaneously with ACS and WFC3. The ORIENT ranges are the maximum allowed with both objects having proper coverage within the WFC and UVIS chips. The visibility is limited to a few weeks around the end of April 2017; unfortunately this is the maximum visibility that is possible for this program (given the necessary ORIENT constraints). ------------------------------------------------------------------------------------ 14643( 3) - 08-Jul-2016 12:52:34 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 2 DFX1+DFX2 GALAXY, UNDESIGNATED RA=13H01M19.7000S, J2000 V = 25 DEC=+27D13'7.00" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 1 DF42+DF44 GALAXY, UNDESIGNATED RA=13H01M19.3600S, J2000 V = 25 DEC=+27D02'44.00" Reference Frame: ICRS ------------------------------------------------------------------------------------------------------------------------------------ 14643( 3) - 08-Jul-2016 12:52:34 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type ACS-WFC-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.262 Line_Spacing 0.192 Coordinate_Frame POS-TARG Pattern_Orient 18.39 Angle_Between_Sides 68.14 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 14643( 3) - 08-Jul-2016 12:52:34 - [ 5] Visit: 01 (DFX1+DFX2 F814W+F606W) Visit Requirements: ORIENT 158D TO 171 D 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DFX1+DFX2 ACS/WFC ACCUM WFC1 F814W 1 500 S GS ACQ SCENARIO BASE1B3; see below PATTERN 1 1-2; PAR 2 (2200 S) WITH 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 ANY WFC3/UVI ACCUM UVIS1 F814W 1 500 S S see below (2420 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 DFX1+DFX2 ACS/WFC ACCUM WFC1 F606W 1 500 S PATTERN 1 3-4; PAR 4 see below WITH 3 (2340 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ANY WFC3/UVI ACCUM UVIS1 F606W 1 500 S S see below (2430 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 | ------------------------------------------------------------------------------------------------------------------------------------ DFX1+DFX2 1 ACS/WFC ACCUM WFC1 F814W 1 none none none 1 430.0 S DFX1+DFX2 1 ACS/WFC ACCUM WFC1 F814W 2 none none none 1 670.0 S DFX1+DFX2 1 ACS/WFC ACCUM WFC1 F814W 3 none none none 1 670.0 S DFX1+DFX2 1 ACS/WFC ACCUM WFC1 F814W 4 none none none 1 430.0 S ANY 2 WFC3/UVI ACCUM UVIS1 F814W 1 none none none 1 510.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F814W 2 none none none 1 700.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F814W 3 none none none 1 700.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F814W 4 none none none 1 510.0 S S DFX1+DFX2 3 ACS/WFC ACCUM WFC1 F606W 1 none none none 2 465.0 S DFX1+DFX2 3 ACS/WFC ACCUM WFC1 F606W 2 none none none 2 705.0 S DFX1+DFX2 3 ACS/WFC ACCUM WFC1 F606W 3 none none none 2 705.0 S DFX1+DFX2 3 ACS/WFC ACCUM WFC1 F606W 4 none none none 2 465.0 S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 2 520.0 S S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 2 700 S S 14643( 3) - 08-Jul-2016 12:52:34 - [ 6] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ANY 4 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 2 700 S S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 4 none none none 2 510 S S 14643( 3) - 08-Jul-2016 12:52:34 - [ 7] Visit: 02 (DFX1+DFX2 F606W+F606W) Visit Requirements: ORIENT 158D TO 171 D 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DFX1+DFX2 ACS/WFC ACCUM WFC1 F606W 1 500 S GS ACQ SCENARIO BASE1B3; see below PATTERN 1 1-2; PAR 2 (2200 S) WITH 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 ANY WFC3/UVI ACCUM UVIS1 F606W 1 500 S S see below (2420 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 DFX1+DFX2 ACS/WFC ACCUM WFC1 F606W 1 500 S PATTERN 1 3-4; PAR 4 see below WITH 3 (2368 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ANY WFC3/UVI ACCUM UVIS1 F606W 1 500 S S see below (2430 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 | ------------------------------------------------------------------------------------------------------------------------------------ DFX1+DFX2 1 ACS/WFC ACCUM WFC1 F606W 1 none none none 1 430.0 S DFX1+DFX2 1 ACS/WFC ACCUM WFC1 F606W 2 none none none 1 670.0 S DFX1+DFX2 1 ACS/WFC ACCUM WFC1 F606W 3 none none none 1 670.0 S DFX1+DFX2 1 ACS/WFC ACCUM WFC1 F606W 4 none none none 1 430.0 S ANY 2 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 1 510.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 1 700.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 1 700.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F606W 4 none none none 1 510.0 S S DFX1+DFX2 3 ACS/WFC ACCUM WFC1 F606W 1 none none none 2 472.0 S DFX1+DFX2 3 ACS/WFC ACCUM WFC1 F606W 2 none none none 2 712.0 S DFX1+DFX2 3 ACS/WFC ACCUM WFC1 F606W 3 none none none 2 712.0 S DFX1+DFX2 3 ACS/WFC ACCUM WFC1 F606W 4 none none none 2 472.0 S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 2 520.0 S S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 2 700 S S 14643( 3) - 08-Jul-2016 12:52:34 - [ 8] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ANY 4 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 2 700 S S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 4 none none none 2 510 S S 14643( 3) - 08-Jul-2016 12:52:34 - [ 9] Visit: 03 (DF42+DF44 F814W+F606W) Visit Requirements: ORIENT 170D TO 185 D 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DF42+DF44 ACS/WFC ACCUM WFC1 F814W 1 500 S PATTERN 1 1-2; PAR 2 see below WITH 1 (2200 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ANY WFC3/UVI ACCUM UVIS1 F814W 1 500 S S see below (2420 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 DF42+DF44 ACS/WFC ACCUM WFC1 F606W 1 500 S PATTERN 1 3-4; PAR 4 see below WITH 3 (2340 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ANY WFC3/UVI ACCUM UVIS1 F606W 1 500 S S see below (2430 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 | ------------------------------------------------------------------------------------------------------------------------------------ DF42+DF44 1 ACS/WFC ACCUM WFC1 F814W 1 none none none 1 430.0 S DF42+DF44 1 ACS/WFC ACCUM WFC1 F814W 2 none none none 1 670.0 S DF42+DF44 1 ACS/WFC ACCUM WFC1 F814W 3 none none none 1 670.0 S DF42+DF44 1 ACS/WFC ACCUM WFC1 F814W 4 none none none 1 430.0 S ANY 2 WFC3/UVI ACCUM UVIS1 F814W 1 none none none 1 510.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F814W 2 none none none 1 700.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F814W 3 none none none 1 700.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F814W 4 none none none 1 510.0 S S DF42+DF44 3 ACS/WFC ACCUM WFC1 F606W 1 none none none 2 465.0 S DF42+DF44 3 ACS/WFC ACCUM WFC1 F606W 2 none none none 2 705.0 S DF42+DF44 3 ACS/WFC ACCUM WFC1 F606W 3 none none none 2 705.0 S DF42+DF44 3 ACS/WFC ACCUM WFC1 F606W 4 none none none 2 465.0 S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 2 520.0 S S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 2 700 S S 14643( 3) - 08-Jul-2016 12:52:34 - [ 10] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ANY 4 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 2 700 S S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 4 none none none 2 510 S S 14643( 3) - 08-Jul-2016 12:52:34 - [ 11] Visit: 04 (DF42+DF44 F606W+F606W) Visit Requirements: ORIENT 170D TO 185 D 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| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 DF42+DF44 ACS/WFC ACCUM WFC1 F606W 1 500 S PATTERN 1 1-2; PAR 2 see below WITH 1 (2200 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 ANY WFC3/UVI ACCUM UVIS1 F606W 1 500 S S see below (2420 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 DF42+DF44 ACS/WFC ACCUM WFC1 F606W 1 500 S PATTERN 1 3-4; PAR 4 see below WITH 3 (2368 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ANY WFC3/UVI ACCUM UVIS1 F606W 1 500 S S see below (2430 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 | ------------------------------------------------------------------------------------------------------------------------------------ DF42+DF44 1 ACS/WFC ACCUM WFC1 F606W 1 none none none 1 430.0 S DF42+DF44 1 ACS/WFC ACCUM WFC1 F606W 2 none none none 1 670.0 S DF42+DF44 1 ACS/WFC ACCUM WFC1 F606W 3 none none none 1 670.0 S DF42+DF44 1 ACS/WFC ACCUM WFC1 F606W 4 none none none 1 430.0 S ANY 2 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 1 510.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 1 700.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 1 700.0 S S ANY 2 WFC3/UVI ACCUM UVIS1 F606W 4 none none none 1 510.0 S S DF42+DF44 3 ACS/WFC ACCUM WFC1 F606W 1 none none none 2 472.0 S DF42+DF44 3 ACS/WFC ACCUM WFC1 F606W 2 none none none 2 712.0 S DF42+DF44 3 ACS/WFC ACCUM WFC1 F606W 3 none none none 2 712.0 S DF42+DF44 3 ACS/WFC ACCUM WFC1 F606W 4 none none none 2 472.0 S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 1 none none none 2 520.0 S S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 2 none none none 2 700 S S 14643( 3) - 08-Jul-2016 12:52:34 - [ 12] 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 | ------------------------------------------------------------------------------------------------------------------------------------ ANY 4 WFC3/UVI ACCUM UVIS1 F606W 3 none none none 2 700 S S ANY 4 WFC3/UVI ACCUM UVIS1 F606W 4 none none none 2 510 S S 14643( 3) - 08-Jul-2016 12:52:34 - [ 13] Summary Form for Proposal 14643 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS1, WFC1 ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GS ACQ SCENARIO BASE1B3, ORIENT 158D TO 171 D, ORIENT 170D TO 185 D, PAR 2 WITH 1, PAR 4 WITH 3, PATTERN 1 1-2, PATTERN 1 3-4 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F606W, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names ANY, DF42+DF44, DFX1+DFX2 ------------------------------------------------------------------------------------------------------------------------------------