0 Assigned ID: 4940 ----- Attempting Submission 1 (Thu Nov 16 04:48:17 GMT 2023) ----- HST Phase I Proposal 4940 successfully submitted. Receipt: # 4940-1 ----- Attempting Submission 2 (Thu Nov 16 04:55:11 GMT 2023) ----- The number of orbits used exceeds the number allocated FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser FLASH level may be too low for this exposure or a short subexposure. See extended explanation in the diagnostic browser The three visits that have 4 exposures have a warning that the FLASH may not be sufficient to avoid CTE effects. I have chosen to use the FLASH given in the UVIS ETC, using the actual position of the object and a zodiacal light model for 1 May 2024. I have added an extra 10-20% to the recommended flash level because of the non-uniform flash illumination. July 2, 2024: I have modified the exposure times to fit within the amount available in Reduced Gyro Mode. I also removed the ORIENT constraints on UCD171 (Visit 1) which made the visit unschedulable. Jan 7, 2025: These comments still apply. Jan 10, 2025: These comments still apply 1002279453 ----- Attempting Submission 1 (Thu Feb 22 03:54:31 GMT 2024) ----- ----- Attempting Submission 2 (Fri Mar 01 22:26:06 GMT 2024) ----- ----- Attempting Submission 3 (Tue Jul 02 19:57:09 GMT 2024) ----- ----- Attempting Submission 4 (Tue Jan 07 20:10:03 GMT 2025) ----- ----- Attempting Submission 5 (Fri Jan 10 22:10:59 GMT 2025) ----- See the submission comments regarding the FLASH levels chosen for the three visits with short exposures. Probing the galactic origin of ultra-compact dwarf galaxies Ultra-compact dwarfs (UCDs) are among the densest stellar systems in the Universe. Their resemblance to nuclear star clusters (NSCs) suggests that they may be the remnants of tidally-stripped dwarfs, but they could also be massive globular clusters. In many cases, it is difficult to determine which is the correct origin scenario. From a new sample of over 600 UCDs and 735 dE,Ns in the nearby Virgo cluster, ~100 objects have been identified that are potentially "caught in the act" of transformation: UCDs with a faint stellar envelope (eUCDs) and dE,Ns with a prominent NSC. Over half of the brightest UCDs have been found to display faint stellar envelopes (eUCDs), but most of the ones with no detectable enevlope also have no HST observations, pointing to a clear observational bias. We aim to remedy this by observing 9 bright Virgo cluster UCDs with WFC3/UVIS to constrain the size of the central star cluster and reveal any existing stellar envelope, and determine the true "galactic" fraction of bright UCDs. Our program is to image 9 bright Virgo cluster ultra-compact dwarf galaxies with WFC3/UVIS/F475W, one orbit for each object, with a corresponding ACS/WFC imaging of nearby fields. Eric Peng (PI) is an expert in the study of dwarf galaxies an compact stellar systems. He was a member of the ACS Virgo Cluster Survey (ACSVCS) team, as well as a core member of the Next Generation Virgo Cluster Survey (NGVS) team. His research group has led numerous papers on globular clusters, dwarf galaxies, ultra-diffuse gaalxies, and ultra-compact galaxies in the Virgo, Fornax, and Coma clusters. Matthew Taylor (co-I) is the PI of a Cycle 1 JWST GO program to search for supermassive black holes in compact stellar systems in the Virgo galaxy cluster. He has led papers on the Centaurus A (NGVS 5128) globular cluster system, and the dark matter content in GCs and UCDs. He has also studies the kinematics of GCs in the halo of M49 (the brightest cluster galaxy in Virgo). He has also led previous HST programs to study the surface brightness profiles of UCDs in Virgo. Galaxies Stellar Populations and the Interstellar Medium 6 false false false false false false SUPPORTED GALAXY DWARF COMPACT J2000 J2000 g'=19.10 GALAXY DWARF COMPACT J2000 J2000 g'=19.40 GALAXY DWARF COMPACT J2000 J2000 g'=19.39 GALAXY DWARF COMPACT J2000 J2000 g'=19.42 GALAXY DWARF COMPACT J2000 J2000 g'=19.46 GALAXY DWARF COMPACT J2000 J2000 g'=19.21 GALAXY DWARF COMPACT J2000 J2000 g'=19.13 GALAXY DWARF COMPACT J2000 J2000 g'=19.40 GALAXY DWARF COMPACT J2000 J2000 g'=19.34 WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F475W WFC3/UVIS Imaging No No F475W ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F475W ACS/WFC Imaging No No F475W POS-TARG DITHER 0.173 LINE 0.112 false false 81.785 4 23.884 WFC3-UVIS-DITHER-BOX 1 false POS-TARG DITHER 0.135 LINE false false 3 46.84 WFC3-UVIS-DITHER-LINE-3PT 2 false The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. ORIENT limits are to avoid a bright (g=12.49) star from landing on the UVIS2 detector or being in the zone where it could cause Dragon's Breath. The best solution is to place this star on the UVIS1 detector. The ORIENT restrictions still enable a wide range of schedulability in April-July 2024. This object is the brightest in the sample, and would potentially be saturated in a 3-exposure visit. Therefore, this visit has 4 exposures, although they are of unequal lengths. The flash level is determined from the ETC, which seems to assume a higher zodiacal light background than the APT does. The post-flash is actually only needed for the first and last UVIS sub-exposures, although I don't seem to be able to set it for individual sub-exposures. In order to mitigate the effects of CTE for the faint stellar envelopes in these shorter exposures, the target was placed using the UVIS2-C1K1C-CTE aperture, but then was offset to allow for a greater range of ORIENT, opening up windows for observation in mid-2024. 1734224695000 294.8827079562409 (Tic-Visit :proposal-id 17597 :visit-id "01" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:13.0" :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 2291888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "01" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2623 :al-overhead-at-end 67 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3010 :pcs-gap 0 ) true 1 0 Necessary flash is estimated from ETC using zodiacal light model for this sky position on 1 May 2024, with an extra 20% to account for the positioning of the target at the UVIS2-C1K1C-CTE aperture. The ETC Run # above is for the shortest exposure (410 sec). The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. ORIENT limits are to avoid a bright (g=12.49) star from landing on the UVIS2 detector or being in the zone where it could cause Dragon's Breath. The best solution is to place this star on the UVIS1 detector. The ORIENT restrictions still enable a wide range of schedulability in April-July 2024. This object is the brightest in the sample, and would potentially be saturated in a 3-exposure visit. Therefore, this visit has 4 exposures, although they are of unequal lengths. The flash level is determined from the ETC, which seems to assume a higher zodiacal light background than the APT does. The post-flash is actually only needed for the first and last UVIS sub-exposures, although I don't seem to be able to set it for individual sub-exposures. In order to mitigate the effects of CTE for the faint stellar envelopes in these shorter exposures, the target was placed using the UVIS2-C1K1C-CTE aperture, but then was offset to allow for a greater range of ORIENT, opening up windows for observation in mid-2024. (Tic-Visit :proposal-id 17597 :visit-id "51" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 12:24:20.0" :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 2291888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "51" :obset-id "51" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "51" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2623 :al-overhead-at-end 67 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3010 :pcs-gap 0 ) true 1 0 Necessary flash is estimated from ETC using zodiacal light model for this sky position on 1 May 2024, with an extra 20% to account for the positioning of the target at the UVIS2-C1K1C-CTE aperture. The ETC Run # above is for the shortest exposure (410 sec). The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17597 :visit-id "02" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:13.0" :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 1718912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2625 :al-overhead-at-end 116 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3015 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 1733100688000 299.82655983743587 (Tic-Visit :proposal-id 17597 :visit-id "03" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:14.0" :trans-errors '(:WARNINGS 1 :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 1718912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2657 :al-overhead-at-end 114 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3015 :pcs-gap 0 ) true 1 1 The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 1733282093000 299.3319125746796 (Tic-Visit :proposal-id 17597 :visit-id "04" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:14.0" :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 1718912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "04" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2625 :al-overhead-at-end 116 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3015 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 1736617633000 311.5489943409424 (Tic-Visit :proposal-id 17597 :visit-id "05" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:15.0" :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 1718912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "05" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2625 :al-overhead-at-end 116 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3015 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. ORIENT limits are to avoid one bright star landing on the ACS/WFC detector. This object is the third brightest in the sample, and would potentially be saturated in a 3-exposure visit. Therefore, this visit has 4 exposures, although they are of unequal lengths. The flash level is determined from the ETC, which seems to assume a higher zodiacal light background than the APT does. The post-flash is actually only needed for the first and last UVIS sub-exposures, although I don't seem to be able to set it for individual sub-exposures. In order to mitigate the effects of CTE for the faint stellar envelopes in these shorter exposures, the target is placed using the UVIS2-C1K1C-CTE aperture. (Tic-Visit :proposal-id 17597 :visit-id "06" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:15.0" :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 2291888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "06" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2623 :al-overhead-at-end 67 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3010 :pcs-gap 0 ) true 1 0 Necessary flash is estimated from ETC using zodiacal light model for this sky position on 1 May 2024. The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. ORIENT limits are to avoid one bright star landing on the ACS/WFC detector. This object is the second brightest in the sample, and would potentially be saturated in a 3-exposure visit. Therefore, this visit has 4 exposures, although they are of unequal lengths. The flash level is determined from the ETC, which seems to assume a higher zodiacal light background than the APT does. The post-flash is actually only needed for the first and last UVIS sub-exposures, although I don't seem to be able to set it for individual sub-exposures. In order to mitigate the effects of CTE for the faint stellar envelopes in these shorter exposures, the target is placed using the UVIS2-C1K1C-CTE aperture. 1736283109000 290.1796782232232 (Tic-Visit :proposal-id 17597 :visit-id "07" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:15.0" :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 2291888 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "07" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2626 :al-overhead-at-end 68 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3015 :pcs-gap 0 ) true 1 0 Necessary flash is estimated from ETC using zodiacal light model for this sky position on 1 May 2024. The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. ORIENT constraints are to avoid two brights stars in the ACS/WFC field of view. 1736288784000 273.8619387789947 (Tic-Visit :proposal-id 17597 :visit-id "08" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:16.0" :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 1718912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "08" :obset-id "08" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "08" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2625 :al-overhead-at-end 116 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3015 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 33.0. CASM was run in Phase II mode. /private/var/folders/_f/t6xjj29s5g73vdxwh4fw0y0h0000gp/T/OPVisit16089960985169995756.xml ORIENT constraints are to avoid two brights stars in the ACS/WFC field of view. (Tic-Visit :proposal-id 17597 :visit-id "58" :proposal-version -1 :trans-version "20241216" :date "10-Jan-2025 15:05:38.0" :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 1718912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "58" :obset-id "58" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "58" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2625 :al-overhead-at-end 116 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3015 :pcs-gap 0 ) true 1 0 The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. ORIENT constraints are to avoid two brights stars in the ACS/WFC field of view. (Tic-Visit :proposal-id 17597 :visit-id "09" :proposal-version -1 :trans-version "20240604" :date "07-Jan-2025 13:07:16.0" :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 1718912 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17597 :visit-id "09" :obset-id "09" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17597 :visit-id "09" :orbit-number 1 :pcs-time 380 :si-vis-utilization 2565 :al-overhead-at-end 116 :internal-dur-at-end 1015 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3015 :pcs-gap 0 ) true 1 0