Unsupported characters were found in Abstract and replaced with |*| Scientific Category is a required field. Science Keywords: Select from 2 to 5 items. Small GO Proposals are not allowed in Cycle 26 unless they are Joint Programs. Please specify your scheduling constraints or 'No Constraints' on all Observation forms. Please specify your scheduling constraints or 'No Constraints' on all Observation forms. 0 Assigned ID: 43 ----- Attempting Submission 1 (Thu Aug 02 13:16:21 GMT 2018) ----- Joint Chandra/HST The primary contact for this phase 2 is Wen-fai Fong (wfong@northwestern.edu). We are resubmitting this with changes in aperture (WFC --> WFC1) and corresponding changes in ORIENT ranges. Valid as of 12/18/2018. -786705267 ----- Attempting Submission 1 (Thu Sep 20 19:19:46 GMT 2018) ----- ----- Attempting Submission 2 (Thu Dec 06 16:21:33 GMT 2018) ----- ----- Attempting Submission 3 (Tue Dec 18 20:37:04 GMT 2018) ----- Late-time monitoring of GW170817 across the electromagnetic spectrum The co-PIs of this proposal are Wen-fai Fong and Raffaella Margutti. We propose joint Chandra-VLA-HST observations to continue our monitoring of the binary neutron star merger GW170817 at t~500-850 days since merger. Our immediate objectives are: (i) to constrain the broad-band spectral evolution of the non-thermal emission from GW170817, and, in particular, the passage of the synchrotron cooling frequency within the Chandra bandpass; (ii) to map the temporal evolution of the emission from GW170817 across the electromagnetic spectrum. These observations are designed to provide new insight into the current debate about the nature of the relativistic ejecta of compact- object mergers and their (now questioned) capability to successfully launch ultra-relativistic jets in their environment. This proposal is for 2 3-orbit visits of the optical counterpart of GW170817 with HST/ACS F606W. These observations are through our approved Chandra Cycle 20 program. Since the counterpart is expected to be extremely faint (>27 AB mag), we ask that the 2 3-orbit visits occur within a 20 days of each other so in the event of non-detection, we can stack all of the images together and have a deep, unprecedented limit at the position. We also ask that observations commence between Jan 1, 2019-Aug 30, 2019 to roughly coincide with our Chandra observations of the source. Earlier times in this range are strongly preferred. We note that GW170817 is a point source on the outskirts of NGC4993, a bright S0 galaxy. 6 false false false false false false false SUPPORTED EXT-STAR GAMMA RAY BURSTER NO This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 ACS/WFC Imaging No No F606W ACS/WFC Imaging No No F606W POS-TARG DITHER 0.262 LINE 0.192 false false 68.14 4 18.39 ACS-WFC-DITHER-BOX 1 false Timing link suitability includes constraints ([02 After 01 by 1.0 to 20.0 days]) The scheduling data was generated by CASM 26.2.2. CASM was run in Phase II mode. First 3-orbit visit of GW170817 to occur between Jan 1, 2019 and Aug 30, 2019, to be roughly coordinated with our first Chandra observation. ORIENT ranges are set to avoid a bright star falling near the edge of the chip, which can cause artifacts across the image. (Tic-Visit :proposal-id 15606 :visit-id "01" :proposal-version -1 :trans-version "20181130" :date "18-Dec-2018 14:32:25.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 3410688 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15606 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15606 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2822 :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 3157 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15606 :visit-id "01" :orbit-number 2 :pcs-time 302 :si-vis-utilization 2852 :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 3157 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15606 :visit-id "01" :orbit-number 3 :pcs-time 302 :si-vis-utilization 2852 :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 3157 :pcs-gap 0 ) true 3 0 Timing link suitability includes constraints ([02 After 01 by 1.0 to 20.0 days]) The scheduling data was generated by CASM 26.2.2. CASM was run in Phase II mode. Second 3-orbit visit of GW170817, to occur within a couple of weeks after the first visit, between Jan 1, 2019 and Aug 30, 2019. ORIENT ranges are set to avoid a bright star falling near the edge of the chip, which can cause artifacts across the image. (Tic-Visit :proposal-id 15606 :visit-id "02" :proposal-version -1 :trans-version "20181130" :date "18-Dec-2018 14:32:38.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 3410688 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15606 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15606 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2822 :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 3157 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15606 :visit-id "02" :orbit-number 2 :pcs-time 302 :si-vis-utilization 2852 :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 3157 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15606 :visit-id "02" :orbit-number 3 :pcs-time 302 :si-vis-utilization 2852 :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 3157 :pcs-gap 0 ) true 3 0