15435( 6) - 18-Jan-2018 21:46:52 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 15435 Version: 6 Check-in Time: 18-Jan-2018 21:46:52 STScI Edit Number: 0 Title The sub-kiloparsec comparison of stellar clumps and molecular gas within the spiral arms of a high-redshift galaxy ------------------------------------------------------------------------------------ Type Cycle GO 25 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. John P Chisholm Observatoire de Geneve Y CoI: Dr. Miroslava Dessauges-Zavadsky Observatoire de Geneve N CoI: Prof. Daniel Schaerer Observatoire de Geneve N CoI: Dr. Antonio Cava Observatoire de Geneve N CoI: Dr. Johan Pierre Richard Centre de Recherche Astrophysique de Lyon N CoI: Dr. Vera Patricio University of Copenhagen, Niels Bohr N Institute ------------------------------------------------------------------------------------ Abstract Unlike local spiral galaxies, high-redshift galaxies typically have extremely clumpy morphologies. Recent simulations suggest that this clumpy morphology arises because extreme inflows of cool gas create gravitational instabilities that fragment the gaseous disk. High sensitivity and spatial resolution observations comparing individual stellar and gaseous clumps are required to provide the irrefutable evidence that fragmentation actually leads to the observed clumpy morphologies. Here we propose HST/WFC3 mid-cycle observations in three bands (F390W, F105W, F160W) of a highly magnified and spatially stretched galaxy at z = 1, where we can study gas and stars at 100 pc resolutions. These observations require a total of 4 orbits. We need mid-cycle observations because we received exceptional ALMA CO(4-3) emission maps in April 2017. Amazingly, these ALMA observations show CO(4-3) emission along the spiral arms of the galaxy. This is the first time that molecular gas has been observed along spiral arms at high redshifts. With the new HST/WFC3 observations we will identify individual stellar clumps, and model their spectral energy distributions to determine their stellar masses, extinction corrected star formation rates, densities and ages. For the first time at z = 1, we will use these observations to establish the evolutionary sequence of stellar clumps, to test the redshift evolution of the Kennicutt-Schmidt law at sub-kpc scales, and to constrain the lifetimes of molecular clouds. This will be the first sub-kpc comparison of individual molecular and stellar clumps within the spiral arms of a high-redshift galaxy. ------------------------------------------------------------------------------------ Observations Description ------------------------ Here, we make observations of the lensed z ~ 1 galaxy Abell0521. We observe the cluster in three HST/WFC3 filters to measure the star formation rate (F390W), stellar age (F105W), and stellar mass (F160W). We center the image at the same position as previous HST/WFPC2 F606W images (PID: 11312). We also use the same orientation constraints (between 270-310 degrees) but include the opposite of the constraints to increase schedulability (90-130 degrees). The opposite orientation would flip the image, but preserve the orientation of the F606W 15435( 6) - 18-Jan-2018 21:46:52 - [ 2] image. We use a four position dither script. We use one orbit for the F390W and F105W images and two orbits for the F160W images. We use a post-exposure flash for the F390W images. ------------------------------------------------------------------------------------ 15435( 6) - 18-Jan-2018 21:46:52 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 A0521 CLUSTER OF GALAXIES, RA=04H54M7.2660S, J2000 V = 16.1 GRAVITATIONAL LENS DEC=-10D14'15.92" Reference Frame: ICRS Extended: YES ------------------------------------------------------------------------------------------------------------------------------------ 15435( 6) - 18-Jan-2018 21:46:52 - [ 4] Patterns ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 1 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-IR-DITHER-BOX-MIN Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 1.716 Line_Spacing 1.095 Coordinate_Frame POS-TARG Pattern_Orient 18.528 Angle_Between_Sides 74.653 Center_Pattern NO Pattern_Comments: We increased the size of the default dither pattern to keep the sub-pixel dithering ------------------------------------------------------------------------------------------------------------------------------------ Pattern_Number: 2 Primary_Pattern Secondary_Pattern Pattern_Type WFC3-UVIS-DITHER-BOX Pattern_Purpose DITHER Number_Of_Points 4 Point_Spacing 0.519 Line_Spacing 0.336 Coordinate_Frame POS-TARG Pattern_Orient 23.884 Angle_Between_Sides 81.785 Center_Pattern NO Pattern_Comments: We increased the size of the default dither pattern to keep the sub-pixel dithering ------------------------------------------------------------------------------------------------------------------------------------ 15435( 6) - 18-Jan-2018 21:46:52 - [ 5] Visit: 02 Visit Requirements: ORIENT 270D TO 300 D; ORIENT 110D TO 130 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 A0521 WFC3/IR MULTIAC IR-FIX F160W NSAMP=14, SAMP-SEQ=SPARS50 1 DEF PATTERN 1 1 CUM (2611.753 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 | ------------------------------------------------------------------------------------------------------------------------------------ A0521 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 15435( 6) - 18-Jan-2018 21:46:52 - [ 6] Visit: 03 Visit Requirements: SAME ORIENT AS 02 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 A0521 WFC3/IR MULTIAC IR-FIX F160W NSAMP=14, SAMP-SEQ=SPARS50 1 DEF PATTERN 1 1 CUM (2611.753 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 | ------------------------------------------------------------------------------------------------------------------------------------ A0521 1 WFC3/IR MULTIAC IR-FIX F160W 1 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F160W 2 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F160W 3 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F160W 4 none none none 1 N/A CUM 15435( 6) - 18-Jan-2018 21:46:52 - [ 7] Visit: 04 Visit Requirements: SAME ORIENT AS 02 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 A0521 WFC3/IR MULTIAC IR-FIX F105W NSAMP=14, SAMP-SEQ=SPARS50 1 DEF PATTERN 1 1 CUM (2611.753 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 | ------------------------------------------------------------------------------------------------------------------------------------ A0521 1 WFC3/IR MULTIAC IR-FIX F105W 1 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F105W 2 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F105W 3 none none none 1 N/A CUM A0521 1 WFC3/IR MULTIAC IR-FIX F105W 4 none none none 1 N/A CUM 15435( 6) - 18-Jan-2018 21:46:52 - [ 8] Visit: 05 Visit Requirements: SAME ORIENT AS 02 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 A0521 WFC3/UVI ACCUM UVIS-FIX F390W FLASH=6 1 617 S PATTERN 2 1 S (2468 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 | ------------------------------------------------------------------------------------------------------------------------------------ A0521 1 WFC3/UVI ACCUM UVIS-FIX F390W 1 none none none 1 N/A S A0521 1 WFC3/UVI ACCUM UVIS-FIX F390W 2 none none none 1 N/A S A0521 1 WFC3/UVI ACCUM UVIS-FIX F390W 3 none none none 1 N/A S A0521 1 WFC3/UVI ACCUM UVIS-FIX F390W 4 none none none 1 N/A S 15435( 6) - 18-Jan-2018 21:46:52 - [ 9] Summary Form for Proposal 15435 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures IR-FIX, UVIS-FIX ------------------------------------------------------------------------------------------------------------------------------------ Configurations WFC3/IR, WFC3/UVIS ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACCUM, MULTIACCUM ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters FLASH=6, NSAMP=14, SAMP-SEQ=SPARS50 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 110D TO 130 D, ORIENT 270D TO 300 D, PATTERN 1 1, PATTERN 2 1, SAME ORIENT AS 02 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements F105W, F160W, F390W ------------------------------------------------------------------------------------------------------------------------------------ Target Names A0521 ------------------------------------------------------------------------------------------------------------------------------------