0 Assigned ID: 5872 ----- Attempting Submission 1 (Tue Mar 26 23:54:50 GMT 2024) ----- After advice from Peter McCullough regarding CTI, I have moved two of my targets to UVIS2-C1K1C-CTE. My more spatially extended targets are now positioned on UVIS2. ------------------- Previous submission: I have spoken to Carol Roderiguez and Peter McCullough regarding dither patterns and POS TARG offsetting for this proposal. I have checked the ETC and the proposed exposure times should not significantly reduce our S/N, and thus will not impact our science goals. -803185495 ----- Attempting Submission 1 (Thu Aug 15 16:12:20 GMT 2024) ----- ----- Attempting Submission 2 (Thu Mar 13 16:55:50 GMT 2025) ----- Double Trouble: Understanding the Origins of Double Peaked Tidal Disruption Events Tidal disruption events (TDEs), the flares produced when a star is disrupted by supermassive black hole, present a unique opportunity to study the accretion processes around black holes, and to probe their fundamental properties. For partial TDEs (pTDEs), events where only a small fraction of the star is disrupted, some cases can exhibit multiple peaks within the light curve, where the star undergoes repeat disruptions as its orbit cyclically brings it back within the vicinity of the black hole. Such events are the holy grail of TDE studies, as their intrinsic set-up provides strong constraints upon the disrupting system. However, they are expected to be extremely rare: approximately 0.1% of the TDE population. Long term monitoring from modern transient surveys have now revealed 5 TDE events whose light curves exhibit two distinct peaks. This unprecedented sample of repeating pTDE candidates is troubling, as it implies repeating pTDEs are far more frequent than theory suggests. Here we propose joint HST WFC3 and Gemini GMOS-IFU observations of the host galaxies of repeating pTDEs, to explore their structure, kinematics and gravitational potential on scales of ~100pc. With these data we will determine if the properties of the host galaxy environment are enhancing the likelihood of repeating pTDEs, and thus elucidate why such a large sample of double peaked TDEs exists. We will obtain UVIS imaging in the F438W, F625W and F814W bands of the host galaxies of 4 repeating partial tidal disruption events. We aim to observe each galaxy to a depth of 26 mag arcsec^-2 in each filter. For each target we will split our observations over 3 visits of 1 orbit, as follows: - Visit 1: 4x ~550~s exposure in F438W in a 4-point dither pattern - Visit 2: 2x ~650s exposure in F438W, 2x 400s exposures in F625W. All observations in a 2-point dither pattern - Visit 3: 2x ~650s exposure in F438W, 2x 350s exposures in F814W. All observations in a 2-point dither pattern A POS TARG offset of +/-0.1 arcsec has been applied to the F438W imaging in visits 2 and 3 to assure that if visits are happen to be executed at the same value of roll angle, the stellar pattern is not aligned on the same pixels. All members of our team have extensive expertise in the study of transients (including SNe and GRBs), and in particular in the study of nuclear transients and flares (TDEs, changing look AGN). Many of us have experience in the study of host galaxy properties (Angus, Nicholl, Raimundo, Ramsden). Angus, Raimundo, Auchettl and Nicholl all have previous experience in the reduction and analysis of HST WFC3 data. PI Angus has previous experience in the PSF modelling of galaxies from high resolution data. Co-I Raimundo has extensive experience in the anlaysis of IFU data of AGN host galaxies and in the interpretation of spatially resolved stellar kinematics. We have substantial experience using HST for studying transient host galaxies (Angus et al. 2016, Nicholl et al. 2018, 2020, Raimundo et al. 2019), and analysing galaxy properties such as star-formation history (Nicholl et al. 2019) and the relationship between SMBHs and their environment (Ramsden et al. 2022). Supermassive Black Holes and Active Galaxies Galaxies 6 false false false false false false true PRIMARY 1.6 true SUPPORTED GALAXY ELLIPTICAL YES This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 GALAXY SPIRAL J2000 J2000 GALAXY DWARF ELLIPTICAL This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 GALAXY ELLIPTICAL This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F625W WFC3/UVIS Imaging No No F438W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F625W WFC3/UVIS Imaging No No F438W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F625W WFC3/UVIS Imaging No No F438W WFC3/UVIS Imaging No No F814W WFC3/UVIS Imaging No No F625W WFC3/UVIS Imaging No No F438W POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 1 false POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 2 false /Users/angus/OP-cache/HST_Phase_II_round2-v01.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17775 :visit-id "01" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:48:05.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2682 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3062 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit12497178555088623793.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. POS TARG offset to avoid same F438W position as first visit if orientation angle the same (Tic-Visit :proposal-id 17775 :visit-id "02" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2682 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3062 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit7594609878382409969.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. POS TARG offset to avoid same F438W position as first/second visit if orientation angle the same (Tic-Visit :proposal-id 17775 :visit-id "03" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2682 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3062 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit13166505775343992144.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17775 :visit-id "04" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "04" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2625 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit12211556614000630324.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. POS TARG offset to avoid same F438W position as first visit if orientation angle the same (Tic-Visit :proposal-id 17775 :visit-id "05" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:03.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "05" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2625 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit16823908112484287356.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. POS TARG offset to avoid same F438W position as first/second visit if orientation angle the same (Tic-Visit :proposal-id 17775 :visit-id "06" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:04.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "06" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2625 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3005 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit16995716447395187214.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17775 :visit-id "07" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:04.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "07" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2669 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3049 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit15014409103368055920.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. POS TARG offset to avoid same F438W position as first visit if orientation angle the same (Tic-Visit :proposal-id 17775 :visit-id "08" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:04.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "08" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2669 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3049 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit11245397039824777562.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. POS TARG offset to avoid same F438W position as first/second visit if orientation angle the same (Tic-Visit :proposal-id 17775 :visit-id "09" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:04.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "09" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2669 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3049 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit2320328366054058878.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17775 :visit-id "10" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:05.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "10" :obset-id "10" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "10" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2652 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3032 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit5447608345274208008.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. POS TARG offset to avoid same F438W position as first visit if orientation angle the same (Tic-Visit :proposal-id 17775 :visit-id "11" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:05.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "11" :obset-id "11" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "11" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2652 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3032 :pcs-gap 0 ) true 1 0 /private/var/folders/s4/c_7gxtx91ynfnzvpql4d8h3h0000gn/T/OPVisit11211162842291724632.xml The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. POS TARG offset to avoid same F438W position as first/second visit if orientation angle the same (Tic-Visit :proposal-id 17775 :visit-id "12" :proposal-version -1 :trans-version "20241216" :date "13-Mar-2025 16:55:05.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 1154992 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17775 :visit-id "12" :obset-id "12" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17775 :visit-id "12" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2652 :al-overhead-at-end 123 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3032 :pcs-gap 0 ) true 1 0