14937( 3) - 14-Aug-2017 14:32:00 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 14937 Version: 3 Check-in Time: 14-Aug-2017 14:32:00 STScI Edit Number: 0 Title Neutral Hydrogen in Tidal Tails: Probing the Extremes of Star Formation ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Mr. Michael Rodruck The Pennsylvania State University Y CoI: Prof. Jane C. Charlton The Pennsylvania State University N CoI: Dr. Sanchayeeta Borthakur Arizona State University N CoI: Dr. Patrick R. Durrell Youngstown State University Y ------------------------------------------------------------------------------------ Abstract The morphologically diverse, HI-rich tidal tails of interacting galaxies represent the edges of the complex parameter space that allows massive star clusters to form and survive. In a prior optical study with the Hubble Space Telescope, our group analyzed 25 tidal tails and their star cluster populations, representing a broad continuum of star/clusterforming activity from a template set of interacting galaxy pairs. Of these 25 tails, we have analyzed and published data on 22 of them. However, our remaining systems, AM 1054-325, MCG-03-13-063, and ESO 376-G028, occupy the extremes of cluster formation: two prolifically cluster-forming environments and one devoid of ongoing star and cluster formation. We propose to observe these systems in the neutral hydrogen 21 cm line with the VLA to gauge the effects of the distribution and kinematics of the HI medium on cluster formation, in the relatively unexplored tidal tail environment. We further propose to age date these clusters with joint HST observations, to link cluster age to the local ISM. Combining these observations with our sample's archival VLA/ATCA data will elucidate the connection between star clusters, the conditions in the HI-dominated ISM that produce them, and holistically, the types of galaxy interactions that promote those conditions. ------------------------------------------------------------------------------------ Observations Description ------------------------ Our program involves U/F336W and B/F438W WFC3 imaging of two interacting galaxies, as part of a successful VLA observing program. We are splitting our 4 orbit request into a pair of 2-orbit visits. We are interested in photometry of faint point- and marginally-resolved sources over the entire WFC3 FOV, and we are requesting a 4 point dither pattern for each filter to properly sample the PSF in our final, combined images. We do not need to cover the chip gap, as long as the ORIENT ranges (below) are OK. We need to make sure the chip gap does not cover area where stars clusters were detected in a previous HST program. Our original request was to have 1.5 orbits in U, and 0.5 orbit in B; however, with the need for a 4-dither pattern, and avoiding any observing inefficiencies with <360s exposures, our best possible observing strategy appears to be 1.3 orbits (U), the rest in B. Although we are interested in the highest possible S/N in our observations, we have left a few x 10s left in each orbit to allow for maximum flexibility in scheduling. Should these cuts be unnecessary, we would like to bump up the F338W observation exposure times as much as is 14937( 3) - 14-Aug-2017 14:32:00 - [ 2] possible. Our ORIENT requests are based on the requirement to cover the WFPC2 footprint from previous observations of these galaxies, but we have found we have many months of available scheduling for each object. We are also trying to avoid a bright star near MCG-03-13-063. NOTE added: we have shifted location of this field to avoid the 'dragons breath' from a nearby star. Finally, we also require a post-FLASH for all images due to the relatively short individual exposures in these blue filters. We used the ETC to look at the expected range of background levels in best and worst-case scenarios for our targets, which have ecliptic latitudes of 35-40 degrees (see links to ETC results below). Note we have assumed a 'best' case scenario where we have the lowest possible zodiacal light, and minimal Earthshine. F438W/B 380s exposures http://etc.stsci.edu/etc/results/WFC3UVIS.im.1004584/ MU_V=22.0 Earth=High airglow=no 7.8 e-/pix HIGH http://etc.stsci.edu/etc/results/WFC3UVIS.im.1004585/ MU_V=23.0 Earth=No airglow=no 2.8 e-/pix LOW Need FLASH=9 to get to 12 e-/pixel F336W/U 850s exposures http://etc.stsci.edu/etc/results/WFC3UVIS.im.1004589/ MU_V=23.0 Earth=no airglow=no 3.2 e-/pix LOW http://etc.stsci.edu/etc/results/WFC3UVIS.im.1004590/ MU_V=22.0 Earth=High airglow=high 5.6 e-/pix LOW Again, need FLASH=9 to get to 12 e-/pixel ------------------------------------------------------------------------------------ 14937( 3) - 14-Aug-2017 14:32:00 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 MCG-03-13-06 GALAXY, INTERACTING RA=05H04M28.1158S, J2000 V = 3321 V = 14.0 3 GALAXY, TIDAL TAIL DEC=-16D35'30.35" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 2 AM-1054-325 GALAXY, INTERACTING RA=10H56M58.4331S, J2000 V = 3850 V = 15. GALAXY, TIDAL TAIL DEC=-33D08'50.91" Reference Frame: Other: SIMBAD Comments: This object was generated by the targetselector and retrieved from the SIMBAD database. ------------------------------------------------------------------------------------------------------------------------------------ 14937( 3) - 14-Aug-2017 14:32:00 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.173 Line_Spacing 0.112 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO ------------------------------------------------------------------------------------------------------------------------------------ 14937( 3) - 14-Aug-2017 14:32:00 - [ 5] Visit: 01 (Visit) Visit Requirements: ORIENT 60D TO 65 D; ORIENT 240D TO 255 D On Hold Comments: Additional Comments: U- and B-band observations of MCG-03-13-063 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 MCG-03-13-0 WFC3/UVI ACCUM UVIS-CENT F336W FLASH=9 1 855 S PATTERN 1 1 63 S ER (3420 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 MCG-03-13-0 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=9 1 380 S PATTERN 1 2 63 S ER (1520 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 | ------------------------------------------------------------------------------------------------------------------------------------ MCG-03-13-063 1 WFC3/UVI ACCUM UVIS-CEN F336W 1 none none none 1 N/A S TER MCG-03-13-063 1 WFC3/UVI ACCUM UVIS-CEN F336W 2 none none none 1 N/A S TER MCG-03-13-063 1 WFC3/UVI ACCUM UVIS-CEN F336W 3 none none none 1 N/A S TER MCG-03-13-063 1 WFC3/UVI ACCUM UVIS-CEN F336W 4 none none none 2 N/A S TER MCG-03-13-063 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER MCG-03-13-063 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER MCG-03-13-063 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER MCG-03-13-063 2 WFC3/UVI ACCUM UVIS-CEN F438W 4 none none none 2 N/A S TER 14937( 3) - 14-Aug-2017 14:32:00 - [ 6] Visit: 02 (Visit) Visit Requirements: ORIENT 270D TO 280 D; ORIENT 92D TO 102 D On Hold Comments: Additional Comments: U- and B-band observations of AM 1054-325 + ESO 376-G028 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 AM-1054-325 WFC3/UVI ACCUM UVIS-CENT F336W FLASH=9 1 860 S PATTERN 1 1 S ER (3440 S) ------------------------------------------------------------------------------------------------------------------------------------ 2 AM-1054-325 WFC3/UVI ACCUM UVIS-CENT F438W FLASH=9 1 380 S PATTERN 1 2 S ER (1520 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 | ------------------------------------------------------------------------------------------------------------------------------------ AM-1054-325 1 WFC3/UVI ACCUM UVIS-CEN F336W 1 none none none 1 N/A S TER AM-1054-325 1 WFC3/UVI ACCUM UVIS-CEN F336W 2 none none none 1 N/A S TER AM-1054-325 1 WFC3/UVI ACCUM UVIS-CEN F336W 3 none none none 1 N/A S TER AM-1054-325 1 WFC3/UVI ACCUM UVIS-CEN F336W 4 none none none 2 N/A S TER AM-1054-325 2 WFC3/UVI ACCUM UVIS-CEN F438W 1 none none none 2 N/A S TER AM-1054-325 2 WFC3/UVI ACCUM UVIS-CEN F438W 2 none none none 2 N/A S TER AM-1054-325 2 WFC3/UVI ACCUM UVIS-CEN F438W 3 none none none 2 N/A S TER AM-1054-325 2 WFC3/UVI ACCUM UVIS-CEN F438W 4 none none none 2 N/A S TER 14937( 3) - 14-Aug-2017 14:32:00 - [ 7] Summary Form for Proposal 14937 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures UVIS-CENTER ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=9 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 240D TO 255 D, ORIENT 270D TO 280 D, ORIENT 60D TO 65 D, ORIENT 92D TO 102 D, PATTERN 1 1, PATTERN 1 2 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F336W, F438W ------------------------------------------------------------------------------------------------------------------------------------ Target Names AM-1054-325, MCG-03-13-063 ------------------------------------------------------------------------------------------------------------------------------------