0 Assigned ID: 1658 ----- Attempting Submission 1 (Tue Mar 20 15:35:38 GMT 2018) ----- HST Phase I Proposal 1658 (Q0302.apt) successfully submitted. Receipt: # 1658-1 ----- Attempting Submission 2 (Tue Mar 20 22:12:00 GMT 2018) ----- HST Phase I Proposal 1658 (Q0302.apt) successfully submitted. Receipt: # 1658-2 ----- Attempting Submission 3 (Wed Mar 21 22:08:07 GMT 2018) ----- Updated the big dither-blob offset from ~3arcsec to ~6arcsec as discussed by mail. -409773146 ----- Attempting Submission 1 (Fri May 18 08:27:34 GMT 2018) ----- ----- Attempting Submission 2 (Wed Aug 15 08:31:57 GMT 2018) ----- 0 We recently discovered that the unobscured QSO LBQS0302-0019 at z=3.286 is actually a dual AGN with an obscured component (dubbed Jil) at 20kpc projected distance. This is the tightest unobscured/obscured dual AGN known at z>3. Subsequently, we detected a galaxy at the location of Jil in a deep K-band image taken during science verification of the adaptive optics system for VLT/HAWK-I in January 2018. The image reveals that both AGN live in massive galaxies as expected for bright AGN at z=3.3. As a natural next step we propose for WFC3/IR F125W observations with HST to 1) resolve the morphology of the two AGN host galaxies at a resolution of 0.1" (4x times better than from ground), 2) detect potential tidal features given the depth provided by HST, and 3) obtain the F125W-K (U-V rest-frame) color which is a proxy for the age and mass-to-light ratio supporting accurate stellar mass measurements. This information is crucial to characterize this extraordinary cosmic dance of these two high-redshift galaxies, particularly, its current interaction stage and stellar mass. The big questions here are: 1) Is the host galaxy of Jil a single distorted galaxy or a merger of two? 2) Did the two galaxies form the majority of their young stars before or after their close encounter? 3) What is the mass ratio and total stellar mass of the system? 4) Is this system hosted by one of the most massive halos at this redshift? With the proposed HST observations this newly discovered dual AGN system will turn into a unique laboratory to understand how massive galaxies and their super-massive black holes formed through merging at high redshift and what role AGN play for their evolution. The observations are aiming to obtain a single high S/N WFC3/IR F125W image of the dual AGN system LBQS 0302-0019. Given a limiting surface brightness of 22mag/arcsec2 (Vega) we compute a minimum exposure time of 8000sec for WFC3/IR F125W if split into 72 individual exposures. The large number of frames are necessary to achieve 1) a good sampling of the PSF and 2) a high contrast imaging for a bright QSO with m_K=15.4mag (Vega). The brightness of the QSO is reaching the saturation level already at 50s long exposures and the sampling of the PSF demands several dithered exposures. The current observing strategiy therefore takes a sequence of short exposures first, followed by a sequence of long exposures which both properly sample the PSF. The short images can replace the saturated pixels of the QSO in the long exposures before combination. In practice we will apply the WFC-IR-DITHER-BLOB dither pattern (2 points separated by 3.2arcsec with the WFC-IF-DITHER-BOX-MIN pattern (4 points for optimal PSF sampling), which leads to 8 dither positions for each of the short and long exposure. For both exposures we will use the IRSUB256 aperture which provides a 25arcsec large FoV which is well sufficient to capture the system for all dither positions. We will employ the SPARS10 read-out sequence with 7 sampling points (i.e. 44sec exposure time) and the SPARS25 read-out sequence with 11 sampling points (i.e. 223sec exposure time) for the short and long exposures, respectively. At each dither position we will obtain 5 and 4 individual exposures for the short and long exposure sequences, respectively. This observing sequence will accumulate in total 1760s of short exposures, aimed at the bright QSO nucleus, and 7136s of long exposures, aimed at the extended diffuse emission of the QSO host galaxy and companion Jil. Galaxies and the IGM Massive Black Holes And Their Host Galaxies 3 false false false false false false SUPPORTED GALAXY HIGH REDSHIFT GALAXY INTERACTING GALAXY QSO YES This object was generated by the targetselector and retrieved from the NED database. J2000 J2000 WFC3/IR Imaging No No F125W POS-TARG DITHER DITHER 4 6.183 WFC3-IR-DITHER-BOX-MIN false 74.653 true 0.365 0.572 2 41.859 POS-TARG WFC3-IR-DITHER-BLOB 18.528 2 true 1534321625911 /tmp/OPVisit1676162472807123974.xml The scheduling data was generated by CASM 25.2. CASM was run in Phase II mode. (Tic-Visit :proposal-id 15480 :visit-id "01" :proposal-version -1 :trans-version "20171009" :date "15-Aug-2018 10:27:05.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 859600 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15480 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15480 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2836 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15480 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2765 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15480 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2814 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15480 :visit-id "01" :orbit-number 4 :pcs-time 222 :si-vis-utilization 2810 :al-overhead-at-end 0 :internal-dur-at-end 412 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) true 4 0