FIxing ORIENT of observations 1289672040 Assigned ID: 704 ----- Attempting Submission 1 (Fri Apr 07 18:21:21 GMT 2017) ----- HST Phase I Proposal 704 (DLA_WFC3IR.apt) successfully submitted. Receipt: # 704-1 ----- Attempting Submission 2 (Fri Apr 07 23:33:17 GMT 2017) ----- Phase II material, resubmitted for HOPR repeat after a failure in our first visit. One orbit. The new visit is altered from the pervious in that we have moved the pointing slightly and restricted the ORIENT range to deal with diffraction spikes. 1002384471 ----- Attempting Submission 1 (Wed Jul 19 15:34:55 GMT 2017) ----- ----- Attempting Submission 2 (Mon Oct 01 13:41:32 GMT 2018) ----- I have run the visit planner. This may be due to resubmitting with a filed visit still attached to the proposal. 0 The direct study of star formation in Damped Lyman Alpha systems (DLAs), the reservoirs of the majority of neutral gas at high redshift, has previously been hampered by the lack of deep integral field spectroscopy for sensitive searches of faint host galaxies. Building on our successful HST "shot-in-the-dark" survey that has probed the in-situ star formation rate of z~2-3 DLAs, we have initiated a MUSE follow-up of 6 DLA signlines to overcome this bottleneck. In the first sightline we have studied, we have uncovered a ~40 kpc Lyman alpha emitting nebula, composed of two clumps within ~50 kpc of the DLA, suggestive of a merger or an extended protodisk. Within this structure, which is the largest nebula known to be associated with a z~3 DLA, we also found a compact continuum source with spectrophotometry consistent with a Lyman Break Galaxy at the same redshift. Aside from the LBG, the rest of the Lyman alpha structure has no continuum counterpart in deep UV and visible imaging. The LBG alone seems unable to power the Lyman alpha nebula and the morphology supports our conclusion that, most likely, this structure is powered by in-situ star formation below detection limit. However, from the Lyman alpha alone the origin of this incredible structure remains ambiguous. With this proposal, we aim to acquire high resolution, deep infrared imaging with HST to probe the rest-frame optical emission to search for the underlying stellar emission of this object and to infer the stellar mass of the LBG. With the powerful combination of HST and MUSE data, we will unravel the nature of this unique system. We aim to detect the stellar light from a Lyman alpha emitting structure associated with a high column absorption line system at z~3 detected in a nearby QSO. Our main requirements are to minimize the impact of the QSO and a nearby bright star on the photometry of the structure. The QSO has H(AB)= 18.33 mag, several magnitude brighter compared to the targeted nebula counterparts which are estimated to be as faint as m(F160W,AB) = 27.56 mag at a separation of 2-6 arcsec. Given this magnitude contrast, it's critical the QSO isn't allowed to contaminate the structure either though diffraction spikes or by dithering the structure on to pixels affected by persistence from the bright quasar. To minimise the impact of diffraction spikes, we select only ORIENT angles which place the diffraction spikes away from the structure identified in Lyman alpha emission. Additionally, there is a bright star with H(AB)~9.0 mag at 45 arcsec away from the QSO and structure. The star is sufficiently bright that it would quickly saturate the detector and its extended PSF could contaminate the object of interest. We will offset the exposures from the default aperture such that the star falls outside the field of view. Because these offsets are in instrument coordinates we have also restricted the ORIENT angles to one single window so that there is no ambiguity in the direction of the offsets. To improve the spatial sampling and aid PSF subtraction, we dither between ramps. To control for persistence, we have adopted the LINE dither pattern to move along the line separating the QSO and the structure. This way the structure never falls on pixels which the QSO has fallen on in past exposures. We will use the longest wavelength wide filter F160W. In order to maximize the S/N for any faint counterparts of the Lyman alpha nebula we have chosen SPARS50 sample sequences with NSAMP=14. With this configuration we can get 4 exposures per orbit with dithers in between. Because we wish to do one dither pattern over the whole visit with a dither in between each exposure, we have selected only one sampling configuration. This leaves us with just 300s unused over the 3 orbits. This strategy gives us the desired S/N of 4.25 for our targeted F160W=27.56 depth. Galaxies and the IGM 6 false false false false false false false SUPPORTED GALAXY EMISSION LINE NEBULA HIGH REDSHIFT GALAXY LYMAN ALPHA CLOUD QUASAR YES The target is a z~4.0 quasar (H_AB=18.33) which was observed to host a Damped Lyman Alpha system at z~3.25 seen in absorption against the QSO continuum. This DLA was followed up with deep imaging and MUSE integral field spectroscopy to reveal an extended Lyman alpha emitting nebula at the same redshift as the DLA. A compact galaxy (I_AB=25.3) also likely embedded in the same structure. The nebula extends 2'' to 6'' from the QSO, the compact galaxy is 2.5'' from the QSO. J025518.58+004847.6 J2000 J2000 QSO H band = 18.33 (AB) GALAXY EMISSION LINE NEBULA HIGH REDSHIFT GALAXY LYMAN ALPHA CLOUD QUASAR YES The coordiates given are offset from the actual target. This is to move a bright star further from the FoV to limit the diffraction spikes. The target is a z~4.0 quasar (H_AB=18.33) which was observed to host a Damped Lyman Alpha system at z~3.25 seen in absorption against the QSO continuum. This DLA was followed up with deep imaging and MUSE integral field spectroscopy to reveal an extended Lyman alpha emitting nebula at the same redshift as the DLA. A compact galaxy (I_AB=25.3) also likely embedded in the same structure. The nebula extends 2'' to 6'' from the QSO, the compact galaxy is 2.5'' from the QSO. J025518.58+004847.6 J2000 J2000 QSO H band = 18.33 (AB) WFC3/IR Imaging No No F160W POS-TARG DITHER 1.5 The purpose of this proposal is to search for a faint continuum counterpart to the Lyman alpha emitting nebula associated with a DLA and get photometry of the compact galaxy. Due to the bright QSO (H_AB=18.33) being in very close proximity to the Lyman alpha nebula (2'') it is critical that persistence from the bright QSO not be allowed to contaminate the photometry of the nebula and compact galaxy. For this reason we have chosen a LINE dither pattern where in each dither we move along the direction connecting the nebula and the QSO such that the nebula never falls on pixels which the QSO fell on in previous exposures. We require dithering to better sample the PSF for subtraction of the QSO. We have chosen dithers which are not an integer number of pixels for this reason. LINE false false 12 330 LINE 1 false POS-TARG DITHER 1.5 The purpose of this proposal is to search for a faint continuum counterpart to the Lyman alpha emitting nebula associated with a DLA and get photometry of the compact galaxy. Due to the bright QSO (H_AB=18.33) being in very close proximity to the Lyman alpha nebula (2'') it is critical that persistence from the bright QSO not be allowed to contaminate the photometry of the nebula and compact galaxy. For this reason we have chosen a LINE dither pattern where in each dither we move along the direction connecting the nebula and the QSO such that the nebula never falls on pixels which the QSO fell on in previous exposures. We require dithering to better sample the PSF for subtraction of the QSO. We have chosen dithers which are not an integer number of pixels for this reason. LINE false false 4 330 LINE 2 false 1538399635660 The scheduling data was generated by CASM 26.0.5. CASM was run in Phase II mode. /Users/ruarimac/Documents/OP-cache/HOPR_v1-v01.xml Due to the proximity of the bright QSO (H_AB=18.33) and the potentially very faint continuum counterparts to the Lyman alpha nebula (F160W=27.56) it is critical the PSF of the QSO not contaminate the nebula or continuum galaxy, particularly the diffraction spikes which means restricting orient ranges. Initially we identified 4 orient ranges which would stop the diffraction spikes from overlapping the nebula. Additionally there is a very bright star close by (45 arcsec, H_AB=9.0) which must be dealt with by placing it outside the field of view. To do this we have offset the target with POS TARG. However because these offsets are in instrument coordinates they would change with different orient angles, and hence we have ultimately restricted the observation to 1 single orient range, the one which maximizes the time over which the visit can be executed. 1535470168000 272.2 (Tic-Visit :proposal-id 15283 :visit-id "01" :proposal-version -1 :trans-version "20180409" :date "01-Oct-2018 15:13:54.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 3133584 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15283 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15283 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2843 :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 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15283 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2843 :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 3202 :pcs-gap 0 ) (Tic-Orbit :proposal-id 15283 :visit-id "01" :orbit-number 3 :pcs-time 222 :si-vis-utilization 2843 :al-overhead-at-end 0 :internal-dur-at-end 614 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) true 3 0 The goal of this proposal is to search for faint continuum counterparts to the Lyman alpha nebula associated with a DLA and to estimate the stellar mass of the compact galaxy. To accomplish the latter we use the longest wavelength wide filter, F160W. In order to maximize the S/N for any faint counterparts of the Lyman alpha nebula we have chosen SPARS50 sample sequences with NSAMP=14. With this configuration we can get 4 exposures per orbit with dithers in between. Because we wish to do one dither pattern over the whole visit with a dither in between each exposure we have selected only one sampling configuration, this leaves us with just 300s unused over the 3 orbits. This strategy gives us a S/N of 4.25 for our targeted F160W=27.56 depth. 1538401173620 The scheduling data was generated by CASM 26.0.5. CASM was run in Phase II mode. /private/var/folders/zt/gwr937155cd_60zm7scnpqxm0000gp/T/OPVisit7558204099133893983.xml This is a repeat of the final orbit of our only visit, which failed due to the lock with the guide star being lost. We are attempting to detect faint galaxies near a quasar (H_AB=18.33), and so we have resticted the ORIENT to prevent the diffraction spikes affecting our targets and to ensure persistence from the quasar does not affect the target. We have also moved the center of the pointing again to further reduce a the affect of a nearby bright star, which was previousllly just outside the field of view. Due to the proximity of the bright QSO (H_AB=18.33) and the potentially very faint continuum counterparts to the Lyman alpha nebula (F160W=27.56) it is critical the PSF of the QSO not contaminate the nebula or continuum galaxy, particularly the diffraction spikes which means restricting orient ranges. Initially we identified 4 orient ranges which would stop the diffraction spikes from overlapping the nebula. Additionally there is a very bright star close by (45 arcsec, H_AB=9.0) which must be dealt with by placing it outside the field of view. To do this we have offset the target with POS TARG. However because these offsets are in instrument coordinates they would change with different orient angles, and hence we have ultimately restricted the observation to 1 single orient range, the one which maximizes the time over which the visit can be executed. (Tic-Visit :proposal-id 15283 :visit-id "51" :proposal-version -1 :trans-version "20180409" :date "01-Oct-2018 15:39:33.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "30" :si-bright-earth-limb-angle 20.0 :data-volume 1044528 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 15283 :visit-id "51" :obset-id "51" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 15283 :visit-id "51" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2843 :al-overhead-at-end 0 :internal-dur-at-end 519 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3202 :pcs-gap 0 ) true 1 0 The goal of this proposal is to search for faint continuum counterparts to the Lyman alpha nebula associated with a DLA and to estimate the stellar mass of the compact galaxy. To accomplish the latter we use the longest wavelength wide filter, F160W. In order to maximize the S/N for any faint counterparts of the Lyman alpha nebula we have chosen SPARS50 sample sequences with NSAMP=14. With this configuration we can get 4 exposures per orbit with dithers in between. Because we wish to do one dither pattern over the whole visit with a dither in between each exposure we have selected only one sampling configuration, this leaves us with just 300s unused over the 3 orbits. This strategy gives us a S/N of 4.25 for our targeted F160W=27.56 depth.