0 Assigned ID: 1352 ----- Attempting Submission 1 (Sat Jan 30 06:59:27 GMT 2021) ----- HST Phase I Proposal 1352 successfully submitted. Receipt: # 1352-1 ----- Attempting Submission 2 (Sat Jan 30 21:50:20 GMT 2021) ----- HST Phase I Proposal 1352 successfully submitted. Receipt: # 1352-2 ----- Attempting Submission 3 (Sun Jan 31 01:09:07 GMT 2021) ----- HST Phase I Proposal 1352 successfully submitted. Receipt: # 1352-3 ----- Attempting Submission 4 (Sun Jan 31 02:56:35 GMT 2021) ----- HST Phase I Proposal 1352 successfully submitted. Receipt: # 1352-4 ----- Attempting Submission 5 (Sun Jan 31 03:09:26 GMT 2021) ----- HST Phase I Proposal 1352 successfully submitted. Receipt: # 1352-5 ----- Attempting Submission 6 (Sun Jan 31 03:39:08 GMT 2021) ----- HST Phase I Proposal 1352 successfully submitted. Receipt: # 1352-6 ----- Attempting Submission 7 (Sun Jan 31 03:41:18 GMT 2021) ----- HST Phase I Proposal 1352 successfully submitted. Receipt: # 1352-7 ----- Attempting Submission 8 (Sun Jan 31 03:58:10 GMT 2021) ----- First submission. APT ver 2020.4.1 used, because APT 2020.5 does not allow submission of Cycle 28 proposals. -1572698225 ----- Attempting Submission 1 (Mon Mar 22 03:45:01 GMT 2021) ----- Failed to run the Target Confirmation Tool in APT 2020.4.1 (the APT does not generate the PDF file). The PI confirmed the target using Aladin and the Target Confirmation Tool in APT ver 2020.5. However, APT 2020.5 does not allow submissions of Cycle 28 midterm proposals. We propose high-resolution ACS imaging to resolve the nature of a newly discovered double quasar system at z=5.66, J2037-4537, which could be either a close quasar pair or a gravitationally lensed quasar. Ground-based observations show that J2037-4537 consists of two point sources separated by 1.26", both of which have a spectrum of a z=5.66 quasar. However, limited by the seeing, it is uncertain whether the lens galaxy exists. The two components are either a physical quasar pair or lensed images of the same quasar. In the former case, J2037-4537 will be the highest redshift quasar pair, which will place strong constraints on the model of AGN formation and evolution, and will enable follow-up observations to study galaxy mergers that trigger quasar activity, to probe the kpc-scale structure of the intergalactic medium at z>5.5 for the first time, and to search for protocluster traced by the quasar pair. In the latter case, J2037-4537 will be the second lensed quasar discovered at z>5 and will be an excellent case study for the high-z SMBH population, aided by lensing magnification. With an Einstein ring size of 1.26", J2037-4537 will provide the best chance to detect the stellar light from a quasar host galaxy at high-z. The key to distinguishing the two scenarios is to detect the lens galaxy. However, the lens galaxy is likely only 0.3" away from the fainter quasar image, which is impossible to get resolved from the ground. Here we propose to use ACS/WFC to confirm (or rule out) the presence of the foreground lens galaxy. With a modest request of 1 orbit, we will identify J2037-4537 as either a lensing system or a close quasar pair and prepare for follow-up observations. This program will perform high-resolution ACS/WFC imaging of a pair of quasar images at z=5.66, which could be either a physical quasar pair or gravitationally lensed images of the same quasar. We will use the F850LP filter. The observation is awarded one orbit which can be finished in one visit. We will do dithering to improve the image sampling. Since we only need one orbit in one visit, we do not expect that the reduced gyro mode will have a significant impact on this project. Minghao Yue works on surveys and follow-up observations of high-redshift lensed quasars, and has extensive experiences in HST data analysis, especially for ACS and WFC3. Prof. Xiaohui Fan is an expert of high-redshift quasar survey, SMBH physics and reionization, and is experienced in HST data analysis. Dr. Jinyi Yang is an expert of high-redshift quasar survey, SMBH physics and reionization, and is experienced in HST data analysis. Dr. Feige Wang is an expert of high-redshift quasar survey, SMBH physics and reionization, and is experienced in HST data analysis. Supermassive Black Holes and Active Galaxies 3 false false false false false false false SUPPORTED GALAXY QSO QUASAR J2000 J2000 DES z = 19.6 ACS/WFC Imaging No No F850LP POS-TARG DITHER 0.262 LINE 0.192 false false 68.14 4 18.39 ACS-WFC-DITHER-BOX 1 false 1616358806501 The scheduling data was generated by CASM 28.2. CASM was run in Phase II mode. /private/var/folders/f9/qm61tlbj79l88v644x05s9z00000gn/T/OPVisit15347216783381413202.xml (Tic-Visit :proposal-id 16507 :visit-id "01" :proposal-version -1 :trans-version "20200619" :date "21-Mar-2021 13:33:26.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1136896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 16507 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 16507 :visit-id "01" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2902 :al-overhead-at-end 0 :internal-dur-at-end 347 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3285 :pcs-gap 0 ) true 1 0