0 Assigned ID: 565 ----- Attempting Submission 1 (Fri Mar 06 16:58:25 GMT 2020) ----- HST Phase I Proposal 565 successfully submitted. Receipt: # 565-1 ----- Attempting Submission 2 (Fri Mar 06 22:58:25 GMT 2020) ----- ORIENT revised in order to avoid neighboring sources within 20 arcsec. July 10th: ORIENT revised to ORIENT=53-59 degrees in order to solve the guide star issue. Oct 17th: New ORIENT=31-32 added in visits 03&04. 2021 Aug 31th: ORIENT in Visits 01&02 are changed to ORI=67-69. -1772806268 ----- Attempting Submission 1 (Mon Jun 29 10:57:52 GMT 2020) ----- HST Phase II Proposal 16295 successfully submitted. Receipt: # 16295-1 ----- Attempting Submission 2 (Tue Jun 30 16:36:50 GMT 2020) ----- ----- Attempting Submission 3 (Thu Jul 09 17:30:38 GMT 2020) ----- ----- Attempting Submission 4 (Sat Oct 17 05:36:32 GMT 2020) ----- ----- Attempting Submission 5 (Mon Aug 30 16:59:16 GMT 2021) ----- A Spectroscopic Redshift for the Most Luminous Galaxy Candidate at z~11 Detailed studies of the ages and star formation histories of the most distant known galaxies promise to provide new insight into the epoch when the first sources emerged from the cosmic dark ages as well as the practicality of using JWST to search for their progenitors. Recent progress analysing the spectral energy distributions of two spectroscopically-confirmed z>9 galaxies, MACS1149_JD1and GNz-11, has been particularly informative. One surprise is the remarkable brightness of GNz-11 at z=11 which suggests that luminous sources may somehow emerge very promptly. Until now, GNz-11 has been regarded as an anomaly. Here we propose to obtain WFC3/G141 grism spectroscopy for a second luminous candidate thought to be at z~10.9, XMM3-3085 with MUV=-23.7 mag. Both sources are consistent with being drawn from the bright end of UV luminosity function at z=5-10. However, as was the case for GNz-11, without a spectroscopic redshift a low redshift interloper or a faint dwarf star cannot be excluded. A suitable spectrum for XMM3-3085 cannot be secured with ground-based instruments because of the low atmospheric transparency at the expected wavelength of its Lyman break. Confirmation of the redshift of XMM3-3085 can be economically secured with HST and would strengthen the evidence supporting the emergence of luminous galaxies at z=11, only 400 Myrs after the Big Bang. This would provide a major impetus for surveys for earlier galaxies with JWST. The goal of this program is to spectroscopically confirm a Lyman break at z~11 for XMM3-3085 (02:26:59.08 -05:12:17.49). We will observe this source for a total of 4 orbits at different orientations. Orientations: In the grism observations, the 4 orbit exposures will be split into two sets of 2 orbit exposures with distinct orientations >30 deg apart. We choose orientation ranges of ORIENT=58-59 and 304-309 degrees (x-axis (direction of the spectral dispersion) is aligned to PAs=13-14 and 259-264 degrees, respectively) to avoid neighboring sources within 20 arcsec. This minimizes contaminating flux from neighboring sources. Choice of instruments and filters: We will use the WFC/G141 grism and a JH_140 filter for direct imaging. According to the photometric redshift uncertainty, the Lyman break should lie within the wavelength range 1.3-1.6 um (at z=10.9+/-1.0), and can be captured with the instrument throughput of >~40% in this configuration. JH_140 imaging is necessary to establish a wavelength calibration for the grism observations. Visit and dither pattern: Our observation strategy is to obtain two visits of 1 orbit at two different orientations. Each visit contains two short pre-images of F140W each followed by a long G141 grism exposure. The two sets of exposures are dithered following the standard two-point dither (WFC3-IR-DITHER-BLOB), i.e., we set POS-TARG: (-1.930, -1.729) (1.930, 1.729). Depth: We have conducted simulations to evaluable the feasibility of the grism observations. Because the photometric redshift is estimated to be z=10.9+/-1.0, we constructed 1000 model galaxy spectra at z=9.9, 10.9, and 11.9 with H=23.9 mag, adding different levels of noise for a range of exposure times based on the HST ETC. We then estimated the signal to noise ratio of the UV continuum in each case. We expect to detect a z=10.9+/-1.0 Lyman break with >10sigma significance with a ~9000 sec exposure. Each grism exposure is accompanied by a 150 seconds direct image exposure in JH_140 in the same manner as undertaken by Oesch et al. (2016). With this exposure time, we can also clearly distinguish the Lyman break from spectra of interlopers. Assuming a science exposure time of 42 minutes per orbit, we require a total of 4 orbits. Dr. Yuichi Harikane has experiences of analyzing HST ACS and WFC3 data, and has published 5 papers in the past 5 years by making use of HST data. Dr Richard Ellis has devoted his scientific career to observations of distant galaxies and has led numerous HST observing programs since the 1990s. Dr. Masami Ouchi and Dr. Yoshiaki Ono are experts in galaxy formation and evolution and cosmic reionization, and have expertise in HST data reduction and analyses for ACS and WFC3. Dr. Ouchi and Ono have led past HST observing programs targeting Lyman alpha emitters, and published >10 papers in the past 5 years by making use of HST data. Galaxies 6 false false false false false false false false SUPPORTED GALAXY HIGH REDSHIFT GALAXY J2000 J2000 H=23.9 ABmag WFC3/IR Spectroscopic No No G141 WFC3/IR Imaging No No F140W /private/var/folders/p2/3w_qr19x3tzbsb32svhxbn_w0000gn/T/OPVisit17881953692123424942.xml The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. 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(Tic-Visit :proposal-id 16295 :visit-id "02" :proposal-version -1 :trans-version "20210514" :date "31-Aug-2021 01:44:08.0" :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 644128 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16295 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16295 :visit-id "02" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2742 :al-overhead-at-end 0 :internal-dur-at-end 310 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) true 1 0 /private/var/folders/p2/3w_qr19x3tzbsb32svhxbn_w0000gn/T/OPVisit1637510931061066468.xml The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 16295 :visit-id "03" :proposal-version -1 :trans-version "20210514" :date "30-Aug-2021 18:27:26.0" :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 644128 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16295 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16295 :visit-id "03" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2742 :al-overhead-at-end 0 :internal-dur-at-end 310 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3145 :pcs-gap 0 ) true 1 0 /private/var/folders/p2/3w_qr19x3tzbsb32svhxbn_w0000gn/T/OPVisit1146547901417016407.xml The scheduling data was generated by CASM 29.2. CASM was run in Phase II mode. 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