0 Assigned ID: 6230 ----- Attempting Submission 1 (Wed Apr 09 14:28:43 GMT 2025) ----- 0 ----- Attempting Submission 1 (Sat Jul 19 15:34:46 GMT 2025) ----- ----- Attempting Submission 2 (Wed Sep 24 16:48:05 GMT 2025) ----- Revealing the Iceberg: Mapping out the Emission Line Nebula in MS1455.0+2232 In low-redshift clusters, such as Perseus and Abell 1795, the warm (10^4K), ionized phase is of critical importance to understanding thermal instabilities in the hot intracluster gas. Maps of Halpha and [O II] have been used for decades to understand how (and how not) cooling proceeds in the intracluster medium. This intermediate-temperature gas, which we think condenses out of the hot phase in areas that are locally out of thermodynamic equilibrium, retains a kinematic imprint of the hot gas, allowing us to probe the turbulence and bulk motion of the 10^8K gas by observing the "fluttering" of cool filaments in the same way that the motion of a flag provides insights into the wind speed and direction. To date there are only a small number (~4) of clusters in which we detect cool multi-phase gas on large enough scales (>50 kpc) that it can be used to provide insights into the details of cooling/feedback physics in the intracluster medium. We have recently discovered what may be the most extreme such system, MS1455.0+2232, which has a network of cool filaments that may extend on scales of ~100kpc, a factor of ~2 larger than the archetype system: the central galaxy in the Perseus cluster. Using a conveniently-located narrow band filter on WFC3-UVIS, we propose to obtain deep narrow-band imagine centered on the [O II] emission line, to make the first deep map of cool 10^4K gas in this system. This system will immediately join a small number of ~4 other clusters with extended emission line nebulae which each have proved critical in understanding cooling, feedback, turbulence in the intracluster medium. The goal of this observing program is to image the central galaxy in MS1455 in three filters: a narrow band centered on redshifted [O II]3727 (F469N), and two broad bands centered on a line-free part of the blue continuum (F390W) and red continuum (F547M). In all cases, our goal is to optimize sensitivity to low surface brightnesses and fine details. I have split the 4-orbit observation in F469N into 8 exposures, with a 2-point dither pattern during each orbit -- I am assuming that the re-acquisition is equivalent to an additional pixel-level dither and so this is really an 8-point pattern that will optimize PSF reconstruction and allow for robust cosmic ray rejection. I have split the broadband observations into 3 exposures each, with ~1.5 orbits per band. This leads to a 2-point pattern for each, along with an orbit for which we just take a fixed-position observation in two bands. In all cases, I have selected the FLASH level such that I do not receive warnings/errors from APT. Everything of interest is located within 0.5' of the target location, and so we can handle any orientation. Prof. Michael McDonald is an expert in studying the cooling and feedback balance in the cores of galaxy clusters. He has extensive experience with a wide variety of data. In particular, he has acquired and published data from several space telescopes, including Chandra, XMM-Newton, Hubble, JWST, Spitzer, Herschel, and GALEX. He has a publication record of 155 papers over the past 10 years. Most relevant to this proposal, McDonald's PhD research focused on mapping out emission line nebula in cluster cores, and he has successfully obtained, reduced, and published Halpha and [O II] narrow-band images of dozens of clusters using ground-based telescopes as well as Hubble. McDonald has guaranteed access to the LLAMAS IFU on Magellan. If this program is successful he will use these resources to obtain the requisite supporting data. Hubble fellow Michael Calzadilla has worked for the past several years on mapping out [O II] emission in the cores of intermediate redshifts with HST. This work has primarily used the ramp filter on ACS, which is significantly more complicated than the setup proposed for here. He has published narrow-band HST data on a half dozen clusters and led a spectroscopic analysis of 100 central cluster galaxies, taking a census of the line-emitting gas in clusters spanning 0 < z < 1.5. Both McDonald and Calzadilla have significant experience with narrow-band imaging of cluster cores, and are very well equipped to carry out the analysis and publication of these data. Co-I Massimo Gaspari is a world expert in simulating the multi-phase gas in the cores of galaxy clusters. He pioneered the use of cool gas kinematics as a probe of the hot gas turbulence, and has written several high impact papers on the origin, excititation, and dynamics of multiphase gas in cluster cores. He will provide theoretical expertise in interpreting the observations from this program. Intergalactic Medium and the Circumgalactic Medium 6 false false false false false false SUPPORTED GALAXY COOLING FLOW ELLIPTICAL EMISSION LINE NEBULA J2000 J2000 WFC3/UVIS Imaging No No F469N WFC3/UVIS Imaging No No F390W WFC3/UVIS Imaging No No F547M POS-TARG DITHER 0.145 LINE false false 2 46.84 WFC3-UVIS-DITHER-LINE 2 false POS-TARG DITHER 0.135 LINE false false 3 46.84 WFC3-UVIS-DITHER-LINE-3PT 3 false /System/Volumes/Data/solaris/user1/mdocher/hst-work/OP-cache/18023-v01.xml The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18023 :visit-id "01" :proposal-version -1 :trans-version "20250624" :date "13-Nov-2025 11:59:36.0" :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 577488 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18023 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18023 :visit-id "01" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2599 :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 2979 :pcs-gap 0 ) true 1 0 /System/Volumes/Data/solaris/user1/mdocher/hst-work/OP-cache/18023-v02.xml The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18023 :visit-id "02" :proposal-version -1 :trans-version "20250624" :date "13-Nov-2025 11:59:36.0" :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 577488 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18023 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18023 :visit-id "02" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2599 :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 2979 :pcs-gap 0 ) true 1 0 /System/Volumes/Data/solaris/user1/mdocher/hst-work/OP-cache/18023-v03.xml The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18023 :visit-id "03" :proposal-version -1 :trans-version "20250624" :date "13-Nov-2025 11:59:36.0" :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 577488 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18023 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18023 :visit-id "03" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2599 :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 2979 :pcs-gap 0 ) true 1 0 /System/Volumes/Data/solaris/user1/mdocher/hst-work/OP-cache/18023-v04.xml The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18023 :visit-id "04" :proposal-version -1 :trans-version "20250624" :date "13-Nov-2025 11:59:36.0" :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 577488 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18023 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18023 :visit-id "04" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2599 :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 2979 :pcs-gap 0 ) true 1 0 /System/Volumes/Data/solaris/user1/mdocher/hst-work/OP-cache/18023-v05.xml The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18023 :visit-id "05" :proposal-version -1 :trans-version "20250624" :date "13-Nov-2025 11:59:36.0" :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 866240 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18023 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18023 :visit-id "05" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2598 :al-overhead-at-end 122 :internal-dur-at-end 352 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) true 1 0 /System/Volumes/Data/solaris/user1/mdocher/hst-work/OP-cache/18023-v06.xml The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18023 :visit-id "06" :proposal-version -1 :trans-version "20250624" :date "13-Nov-2025 11:59:36.0" :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 866240 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18023 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18023 :visit-id "06" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2597 :al-overhead-at-end 123 :internal-dur-at-end 352 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) true 1 0 /System/Volumes/Data/solaris/user1/mdocher/hst-work/OP-cache/18023-v07.xml The scheduling data was generated by CASM 33.1. CASM was run in Phase II mode. (Tic-Visit :proposal-id 18023 :visit-id "07" :proposal-version -1 :trans-version "20250624" :date "13-Nov-2025 11:59:23.0" :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 866240 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 18023 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 18023 :visit-id "07" :orbit-number 1 :pcs-time 301 :si-vis-utilization 2597 :al-overhead-at-end 125 :internal-dur-at-end 352 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2979 :pcs-gap 0 ) true 1 0