Science Keywords: Select from 2 to 5 items. 0 Assigned ID: 3801 ----- Attempting Submission 1 (Tue Aug 30 15:04:25 GMT 2022) ----- Joint Chandra/HST Changed aperture UVIS1 to UVIS2 on advice of contact scientist to improve UV sensitivity -1810588285 ----- Attempting Submission 1 (Mon Sep 26 15:53:04 GMT 2022) ----- ----- Attempting Submission 2 (Tue Feb 07 09:11:17 GMT 2023) ----- Tidal disruption events unveiled: understanding their long-term accretion with Chandra and HST Tidal disruption events (TDEs) provide a unique laboratory for studying supermassive black holes. Shortly after disruption, most TDEs are 'veiled': emitting mainly UV/optical while X-ray signs of accretion are obscured. However by >~3 years, the stellar debris should settle into a thin, unobscured disk, brightest in X-rays and UV. We propose to observe 3 very nearby and well-studied TDEs at late phases using Chandra and HST. Only previous 1 TDE (and no veiled TDEs) have high S/N X-ray data at late times. Covering the SED peak with X-ray+UV reveals (1) the evolution of the accretion rate, and whether embedded accretion powered the optical flare; (2) the dominant energy release mechanism in the disk; and (3) fundamental disk parameters such as masses and possibly spin. We will obtain WFC3/UVIS imaging in F225W of the three closest TDEs to date at phases of >~4 years post-disruption. This is achievable at an SNR~10-30 with one orbit per target. We will simultaneously obtain X-ray observations to measure the UV-X-ray spectral slope. n/a Supermassive Black Holes and Active Galaxies 6 false false false false false false false SUPPORTED EXT-STAR X-RAY TRANSIENT NO This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 F225W ~ 23.6 EXT-STAR X-RAY TRANSIENT NO This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 F225W ~ 24 EXT-STAR X-RAY TRANSIENT NO This object was generated by the targetselector and retrieved from the SIMBAD database. J2000 J2000 F225W ~ 24.9 WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F225W WFC3/UVIS Imaging No No F225W POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 1 false /private/var/folders/dj/r5399n6n2dbbgd_6ppfdtng40000gn/T/OPVisit2533734690094870921.xml The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17236 :visit-id "01" :proposal-version -1 :trans-version "20220630" :date "07-Feb-2023 09:07:44.0" :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 17236 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17236 :visit-id "01" :orbit-number 1 :pcs-time 383 :si-vis-utilization 2765 :al-overhead-at-end 127 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) true 1 0 Questions: 1. Is this the optimal FLASH to use? 2. Targets are at the centers of galaxies ~1 arcmin across. We want to include the whole galaxy in each image as this enables additional science. Is UVIS1 the best location to put the galaxy on the chip? /private/var/folders/dj/r5399n6n2dbbgd_6ppfdtng40000gn/T/OPVisit13758984800771365621.xml The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17236 :visit-id "02" :proposal-version -1 :trans-version "20220630" :date "07-Feb-2023 09:07:57.0" :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 17236 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17236 :visit-id "02" :orbit-number 1 :pcs-time 383 :si-vis-utilization 3025 :al-overhead-at-end 127 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3411 :pcs-gap 0 ) true 1 0 Questions: 1. Is this the optimal FLASH to use? 2. Targets are at the centers of galaxies ~1 arcmin across. We want to include the whole galaxy in each image as this enables additional science. Is UVIS1 the best location to put the galaxy on the chip? /private/var/folders/dj/r5399n6n2dbbgd_6ppfdtng40000gn/T/OPVisit125703197649917639.xml The scheduling data was generated by CASM 30.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17236 :visit-id "03" :proposal-version -1 :trans-version "20220630" :date "07-Feb-2023 09:08:01.0" :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 1154976 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17236 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17236 :visit-id "03" :orbit-number 1 :pcs-time 383 :si-vis-utilization 3101 :al-overhead-at-end 127 :internal-dur-at-end 668 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3486 :pcs-gap 0 ) true 1 0 Questions: 1. Is this the optimal FLASH to use? 2. Targets are at the centers of galaxies ~1 arcmin across. We want to include the whole galaxy in each image as this enables additional science. Is UVIS1 the best location to put the galaxy on the chip?