16848( 5) - 14-Oct-2021 14:17:14 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 16848 Version: 5 Check-in Time: 14-Oct-2021 14:17:14 STScI Edit Number: 2 Title Imaging of Compact Cluster HCG 40 ------------------------------------------------------------------------------------ Type Cycle GO/DD 28 ------------------------------------------------------------------------------------ Investigators Contact? PI: Christopher Britt Space Telescope Science Institute Y CoI: Quyen Hart Space Telescope Science Institute Y CoI: Max Mutchler Space Telescope Science Institute Y CoI: Joseph DePasquale Space Telescope Science Institute N CoI: Alyssa Pagan Space Telescope Science Institute N CoI: Holly Ryer (Greathouse) Space Telescope Science Institute N CoI: Ray Villard Space Telescope Science Institute N CoI: Christine Pulliam Space Telescope Science Institute N ------------------------------------------------------------------------------------ Abstract HCG 40, or Arp 321, is a compact galaxy group with 5 cluster members. Member galaxies include an optical AGN and galaxies at a variety of star formation rates as measured in both UV and IR, though no Hubble data on these objects yet exists. We propose to take broadband optical and H-alpha observations of HCG 40. ------------------------------------------------------------------------------------ Observations Description ------------------------ We will obtain high signal-to-noise imaging of the compact galaxy group Arp 321, or HCG 40, with both broad and narrow band optical filters using the WFC3/UVIS instrument. No previous Hubble observations of this group exist. We propose to take new F475W, F606W, F814W, and F665N observations with WFC3/UVIS. The faintest and smallest member of HCG 40 has a total magnitude of R=15.4 and B=17.4, while the brightest and largest has a total magnitude of R=12.2 and B=13.8. Altogether, we request 6 orbits to make these observations. Using Arp 220 as a template spectrum in the WFC3/UVIS Exposure Time Calculator, we can achieve a S/N ratio of at least 100 per resolution element in F475W, F606W, and F814W with exposures of 2400s in F475W, 1000s in F606W, and 1100s in F814W, for the brightest cluster member, and at least 50 per resolution element in the faintest cluster member with 3600s in F814W. We can achieve high signal to noise for quality imaging by splitting 3 orbits between the broad-band filters. To highlight regions with high star formation activity, we request an additional 3 orbits with F665N on WFC3, which will reach high S/N in those areas and highlight the strong differences in star formation rate between cluster members. HCG 40 is at a redshift of z=0.0223, which still falls within the F665N filter's coverage. This filter is unavailable on ACS. The WFC3 field of view is also sufficient to encompass the entire cluster without constraint on orientation. We propose a single WFC3 pointing with a 3-point gap dither to mitigate artifacts such as cosmic rays, hot pixels, and the interchip gap. At the same time as the primary WFC3 observations, we will obtain parallel observations with ACS in F475W and F606W. The WFC3 dither shift is oversized a bit so that it also covers the ACS chip gap in the parallel field. With 3 16848( 5) - 14-Oct-2021 14:17:14 - [ 2] orbits in each ACS filter we expect to detect many faint background galaxies in the parallel field. This target is schedulable in late 2021 at the desired orient. Scheduling as early as possible in November is ideal. ------------------------------------------------------------------------------------ 16848( 5) - 14-Oct-2021 14:17:14 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 ARP-321 CLUSTER OF GALAXIES, RA=09H38M55.2487S, J2000 V = 13.3 +/- 0.2 Magnitude is total for GROUP, INTERACTING DEC=-04D51'10.35" brightest cluster member, which also GALAXY, TIDAL TAIL occupies roughly 30 square arcseconds. Reference Frame: Other: SIMBAD Extended: YES Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2015.5 0.0 0.0 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 16848( 5) - 14-Oct-2021 14:17:14 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type LINE Pattern_Purpose DITHER Number_Of_Points 3 Point_Spacing 5 Line_Spacing Coordinate_Frame POS-TARG Pattern_Orient 87 Angle_Between_Sides Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 16848( 5) - 14-Oct-2021 14:17:14 - [ 5] Visit: 01 Visit Requirements: ORIENT 268D TO 285 D; BEFORE 06-DEC-2021:00:00:00 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 ARP-321 WFC3/UVI ACCUM UVIS-CENT F475W CR-SPLIT=NO, FLASH=2 1 900 S GS ACQ SCENARIO BASE1BE; S ER (2700 S) PATTERN 1 1-4; PAR 4 WITH 1-3 ------------------------------------------------------------------------------------------------------------------------------------ 2 ARP-321 WFC3/UVI ACCUM UVIS-CENT F606W CR-SPLIT=NO 1 700 S S ER (2100 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 ARP-321 WFC3/UVI ACCUM UVIS-CENT F814W CR-SPLIT=NO, FLASH=2 1 800 S S ER (2400 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 ANY ACS/WFC ACCUM WFCENTER F606W 2 1100 S (6600 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 | ------------------------------------------------------------------------------------------------------------------------------------ ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F475W 1 none none none 1 N/A S TER ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F475W 2 none none none 2 N/A S TER ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F475W 3 none none none 3 N/A S TER ARP-321 2 WFC3/UVI ACCUM UVIS-CEN F606W 1 none none none 1 N/A S TER ARP-321 2 WFC3/UVI ACCUM UVIS-CEN F606W 2 none none none 2 N/A S TER ARP-321 2 WFC3/UVI ACCUM UVIS-CEN F606W 3 none none none 3 N/A S TER ARP-321 3 WFC3/UVI ACCUM UVIS-CEN F814W 1 none none none 1 N/A S TER ARP-321 3 WFC3/UVI ACCUM UVIS-CEN F814W 2 none none none 2 N/A S TER ARP-321 3 WFC3/UVI ACCUM UVIS-CEN F814W 3 none none none 3 N/A S TER ANY 4 ACS/WFC ACCUM WFCENTER F606W 1 none 1 none 1 N/A ANY 4 ACS/WFC ACCUM WFCENTER F606W 1 none 2 none 1 N/A ANY 4 ACS/WFC ACCUM WFCENTER F606W 2 none 1 none 2 N/A ANY 4 ACS/WFC ACCUM WFCENTER F606W 2 none 2 none 2 N/A ANY 4 ACS/WFC ACCUM WFCENTER F606W 3 none 1 none 3 N/A 16848( 5) - 14-Oct-2021 14:17:14 - [ 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 ACS/WFC ACCUM WFCENTER F606W 3 none 2 none 3 N/A 16848( 5) - 14-Oct-2021 14:17:14 - [ 7] Visit: 02 Visit Requirements: SAME ORIENT AS 01; BEFORE 06-DEC-2021:00:00:00 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 ARP-321 WFC3/UVI ACCUM UVIS-CENT F665N CR-SPLIT=NO, FLASH=15 2 1230 S GS ACQ SCENARIO BASE1BE; S ER (7380 S) PATTERN 1 1-2; PAR 2 WITH 1 ------------------------------------------------------------------------------------------------------------------------------------ 2 ANY ACS/WFC ACCUM WFCENTER F475W 2 1100 S (6600 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 | ------------------------------------------------------------------------------------------------------------------------------------ ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F665N 1 none 1 none 1 N/A S TER ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F665N 1 none 2 none 1 N/A S TER ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F665N 2 none 1 none 2 N/A S TER ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F665N 2 none 2 none 2 N/A S TER ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F665N 3 none 1 none 3 N/A S TER ARP-321 1 WFC3/UVI ACCUM UVIS-CEN F665N 3 none 2 none 3 N/A S TER ANY 2 ACS/WFC ACCUM WFCENTER F475W 1 none 1 none 1 N/A ANY 2 ACS/WFC ACCUM WFCENTER F475W 1 none 2 none 1 N/A ANY 2 ACS/WFC ACCUM WFCENTER F475W 2 none 1 none 2 N/A ANY 2 ACS/WFC ACCUM WFCENTER F475W 2 none 2 none 2 N/A ANY 2 ACS/WFC ACCUM WFCENTER F475W 3 none 1 none 3 N/A ANY 2 ACS/WFC ACCUM WFCENTER F475W 3 none 2 none 3 N/A 16848( 5) - 14-Oct-2021 14:17:14 - [ 8] Summary Form for Proposal 16848 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER, WFCENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations ACS/WFC, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters CR-SPLIT=NO, FLASH=15, FLASH=2 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements BEFORE 06-DEC-2021:00:00:00, GS ACQ SCENARIO BASE1BE, ORIENT 268D TO 285 D, PAR 2 WITH 1, PAR 4 WITH 1-3, PATTERN 1 1-2, PATTERN 1 1-4, SAME ORIENT AS 01 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F475W, F606W, F665N, F814W ------------------------------------------------------------------------------------------------------------------------------------ Target Names ANY, ARP-321 ------------------------------------------------------------------------------------------------------------------------------------