0 Assigned ID: 1159 ----- Attempting Submission 1 (Fri Sep 27 22:49:34 GMT 2019) ----- HST Phase I Proposal 1159 (c27mc1_z9.apt) successfully submitted. Receipt: # 1159-1 ----- Attempting Submission 2 (Fri Sep 27 22:51:55 GMT 2019) ----- HST Phase I Proposal 1159 (c27mc1_z9.apt) successfully submitted. Receipt: # 1159-2 ----- Attempting Submission 3 (Fri Sep 27 23:56:22 GMT 2019) ----- HST Phase I Proposal 1159 (c27mc1_z9.apt) successfully submitted. Receipt: # 1159-3 ----- Attempting Submission 4 (Sat Sep 28 00:03:37 GMT 2019) ----- HST Phase I Proposal 1159 (c27mc1_z9.apt) successfully submitted. Receipt: # 1159-4 ----- Attempting Submission 5 (Sat Sep 28 00:48:36 GMT 2019) ----- HST Phase I Proposal 1159 (c27mc1_z9.apt) successfully submitted. Receipt: # 1159-5 0 ----- Attempting Submission 1 (Sun Nov 17 13:48:51 GMT 2019) ----- Securing a sample of exceptionally bright z>~9 galaxies to prepare for JWST and probe early galaxy assembly Especially massive galaxies are thought to be rare in the high-redshift universe, so the discovery of one very bright z=11.1 galaxy (GN-z11) within the original CANDELS program (0.25 sq. deg) was quite a surprise. Most theoretical models suggested a 10-50x larger area would be required to identify such a source. While such a discovery could suggest high-mass galaxies form particularly efficiently at early times, it could also be a "lucky" find. To determine which and to probe the properties of the most massive assembled galaxies in the early universe, we search a much larger volume for bright z>8.5 galaxies and discovered 4 very bright, high-probability z~9-10 candidate galaxies over that 6 square degree area with the deepest optical, near-IR, and Spitzer/IRAC data. The extreme luminosities of these sources demands that we urgently try to confirm their nature as secure z>8 galaxies with deeper follow-up observations given the implications for the formation efficiency of massive galaxies in the early universe and the proximity of the JWST cycle 1 deadline. With just 1 orbit of HST imaging data at 0.1 micron, these candidates would be detected at 10 sigma if at z<7, or be found to be secure >99.9999%-probability z>8 galaxies if undetected. Thanks to the very large volumes we search, we will likely confirm 1 of these extreme sources as robust, and potentially more if galaxy formation is especially efficient at early times. Our resultant sample of exceptionally bright z~9-10 galaxies should serve as high value targets for deep spectroscopy in the near future with JWST, ALMA, and also with the ELTs. We observe 4 candidate ultrabright (mH~24-24.5 A) star-forming galaxies at z>8.5. Each source is observed during one visit for one orbit split between imaging in the F105W (~0.8 orbit) and F140W (~0.2 orbit) bands. We adopt a 4-point dither strategy in F105W (3-point for F140W), similar to the WFC3-IR-DITHER-BOX-MIN pattern, to improve spatial sampling and limit systematics from potential cosmetic defects and residual cosmic ray hits, and alternating observations in the F140W to those in the F105W band, to optimize the time available for integration. Furthermore, each orbit starts and ends with observations in the F140W, to limit the contamination from HeII emission that could affect the F105W band at low limb angles from earth. We minimized the sampling time of each integration to pursue optimal cosmic ray rejection. In the event of Reduced Gyro Mode, given the current short (17-20sec) unused time in each orbit, our observing strategy would need minor revision to accommodate the additional ~2minutes required for the initial target acquisition. Rychard Bouwens, Garth Illingworth, Pascal Oesch, Ivo Labbe, and Mauro Stefanon are experts on high-redshift galaxy evolution. Rychard Bouwens, Pascal Oesch, Ivo Labbe, and Mauro Stefanon and Gabriel Brammer have significant experience working with HST, Spitzer/IRAC, and other data, selecting distant galaxies from such observations, determining the photometric redshifts of sources, and inferring various physical properties of distant sources from these observations (UV slopes, stellar masses, etc.). Cosmology 0 false false false false true false false SUPPORTED GALAXY HIGH REDSHIFT GALAXY J2000 J2000 H=24 AB GALAXY HIGH REDSHIFT GALAXY J2000 J2000 H=24 AB GALAXY HIGH REDSHIFT GALAXY J2000 J2000 H=24 AB GALAXY HIGH REDSHIFT GALAXY J2000 J2000 H=24 AB WFC3/IR Imaging No No F105W WFC3/IR Imaging No No F105W WFC3/IR Imaging No No F105W WFC3/IR Imaging No No F105W The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16037 :visit-id "01" :proposal-version -1 :trans-version "20190514" :date "15-Nov-2019 16:59:57.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1270848 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16037 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16037 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2792 :al-overhead-at-end 0 :internal-dur-at-end 386 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16037 :visit-id "02" :proposal-version -1 :trans-version "20190514" :date "15-Nov-2019 17:00:01.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1270848 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16037 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16037 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2792 :al-overhead-at-end 0 :internal-dur-at-end 386 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16037 :visit-id "03" :proposal-version -1 :trans-version "20190514" :date "15-Nov-2019 17:00:05.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1270848 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16037 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16037 :visit-id "03" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2792 :al-overhead-at-end 0 :internal-dur-at-end 386 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) false 1 0 The scheduling data was generated by CASM 27.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16037 :visit-id "04" :proposal-version -1 :trans-version "20190514" :date "15-Nov-2019 17:00:08.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1270848 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16037 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16037 :visit-id "04" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2792 :al-overhead-at-end 0 :internal-dur-at-end 386 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3142 :pcs-gap 0 ) true 1 0