changed to BASE1TNS removed ACS parallels ----- Submission 1 (Tue May 02 20:07:58 GMT 2006) ----- ----- Submission 2 (Wed Aug 02 14:14:57 GMT 2006) ----- Phase II Proposal 10924 (10924) successfully submitted. ----- Submission 3 (Wed Aug 02 15:01:14 GMT 2006) ----- ----- Attempting Submission 4 (Wed Feb 21 09:01:33 EST 2007) ----- none Assigned ID: 268 ----- Submission 1 (Fri Jan 27 16:49:42 GMT 2006) ----- Constraints on the Assembly and Dynamical Masses of z~2 Galaxies We propose deep NICMOS/NIC2 F160W imaging of seven star-forming galaxies at z~2. These galaxies comprise an entirely unique sample, with not only redshifts measured from optical and near-IR spectra, but also SINFONI/VLT near-IR integral field spectroscopic measurements providing kinematic maps of H-alpha emission out to radii of >=10 kpc. We aim to determine the dynamical masses and evolutionary states of these systems, as part of the larger goal of understanding how mass is assembled in distant galaxies. In order to interpret our novel H-alpha integral field maps in terms of mass, we require detailed knowledge of the structural parameters of our target objects at rest-frame optical wavelengths and on ~1 kpc scales. We want to establish if the mass is distributed in a disk, bulge, or merging sub-units, and if we can detect tidal features associated with a merger. F160W imaging with NICMOS/NIC2 provides the perfect combination of sensitivity and resolution to address these questions, and arrive at the fundamental quantity: the dynamical mass.
We are proposing deep NICMOS/NIC2 imaging for seven individual $z\sim 2$ star-forming galaxy targets. We have obtained detailed H$\alpha$ kinematic maps of these galaxies using the SINFONI near-IR integral field spectrograph. With detail unprecedented for high-redshift galaxy observations, these seeing-limited yet spatially-resolved maps indicate systematic variations in velocity as a function of position. We now require the $\sim$kpc-scale resolution that NICMOS/NIC2 provides in order to determine the underlying morphological structure, and therefore the evolutionary state and dynamical mass of each of these systems. We have opted for NIC2 over the lower-resolution, wider-field NIC3 camera, since detailed diffraction-limited observations of individual galaxies are our highest priority rather than surveying the largest possible area. NIC2 is also preferable to the significantly less-sensitive NIC1, whose finer sampling does not provide any advantage in resolution over NIC2, which critically samples the HST point-spread function at 1.6~$\mu$m. In terms of wavelength, we argue in the Scientific Justification that rest-frame optical light probes the bulk of the stellar mass more reliably than the rest-frame UV, which traces only the most recent episode of star-formation and is more affected by dust extinction. In order to probe the rest-frame optical at $z\sim 2$, we propose to use the F160W filter, the central wavelength of which corresponds to rest-frame $\sim 5000$\AA\ for our targets. This filter probes the longest wavelength at which the HST thermal emission is unimportant, taking full advantage of the lack of the sky background that limits the sensitivity of ground-based near-IR observations. We have estimated the required exposure times as follows: for 5 of the 7 proposed targets, we have measured $J$ and $K_s$-band magnitudes in addition to optical photometry. We have modeled the $U_nG{\cal R}JK_s$ SEDs of these objects using simple stellar population synthesis models (Shapley et al. 2005; Erb et al. 2006), and used the interpolated $H$-band magnitude of the best-fit model as a proxy for the brightness in the F160W filter. The estimated $H$ band magnitudes range from $20.1 - 21.5$ (Vega). While we don't have $J$ or $K_s$-band information for SSA22a-MD41 or Q2346-BX482, we assume that their $H$-band magnitudes fall within the range spanned by the remainder of the sample. This is a reasonable assumption given that MD41 and BX482 are comparable to other objects in the proposed sample in terms of kinematic properties and size. Based on the seeing-limited spatial information in our SINFONI H$\alpha$ maps, and HST/ACS F814W images of SSA22a-MD41 and Q1700-BX691 (which may not be representative of the rest-frame optical extent, but at least provide an upper limit), we estimate that our targets have areas ranging from $1.0 - 3.0$ arcsec$^2$, with {\it average} surface brightnesses ranging from $20.5 \leq \mu_H \leq 22.5$~mag/arcsec$^2$. In order to study the detailed morphologies of our targets, we must be able to discern contrast on $\sim 1$~kpc scales, corresponding roughly to the $2\times 2$-pixel NIC2 resolution element. We will obtain an average S/N$>10$ per resolution element for typical objects in our samples in $\sim 8000$~seconds, assuming average to high levels for the zodiacal light and earthshine backgrounds. In such exposure times, we will achieve S/N$>5$ per resolution element on average for the faintest objects in our sample, our baseline requirement. In order to calculate the required orbits we assume that the exposures will be obtained in $\sim 600-700$~second increments, allowing for 16 independent dither positions to minimize the effects of cosmic-rays, persistence, and flat-fielding. We will use four 4-position NIC-SPIRAL-DITH dither sequences offset from each other by an integer-pixel amount. Within each 4-position dither sequence we plan to use integer+half-pixel offsets to ensure that the PSF is very well sampled, crucial for determining galaxy structural parameters. Our targets range in visibility from $52-54$ minutes per orbit. Accounting for the 6 minute guide-star acquisition time and typical values for instrument overhead (i.e. MULTIACCUM read-out, small dithers, and filter set-up) leads to an estimate of $2650-2750$~second per orbit for science integration time. We therefore require 4 orbits per target. For the brighter objects in the sample, these exposure times will allow us to push the envelope in terms of detecting significant brightness contrast on small scales. Finally, we note that both SSA22a-MD41 and Q1700-BX691 are contained in existing 10-orbit ACS/F814W images (PI: Abraham, ID:9760; PI: Shapley, ID: 10581). Our analysis will gain an extra dimension from the comparison of deep rest-frame UV and optical morphologies for these objects, along with their spatially-resolved H$\alpha$ kinematic information. {\bf Parallels:} We are requesting ACS/F814W parallels for the duration of our NICMOS/NIC2 observations (as well as NIC1 and NIC3 parallels). We will attempt to constrain the value of ``ORIENT,'' so that the ACS/WFC field falls within our larger UV-selected survey fields. In these fields we have assembled a large body of information about the properties of star-forming galaxies at $z\sim 2$, which will be enhanced with rest-frame UV morphological information. COSMOLOGY 12 false 0.0 false false false false false false SUPPORTED GALAXY HIGH REDSHIFT GALAXY K=19.8 J2000 16 26 56.4390 +26 50 15.44 J2000 GALAXY HIGH REDSHIFT GALAXY K=19.9 J2000 16 26 4.5760 +26 48 0.20 J2000 GALAXY HIGH REDSHIFT GALAXY K=20.7 J2000 17 01 6.0100 +64 12 10.11 J2000 GALAXY HIGH REDSHIFT GALAXY J2000 22 17 39.9610 +00 17 11.08 J2000 GALAXY HIGH REDSHIFT GALAXY K=20.2 J2000 23 46 28.8970 +12 47 33.54 J2000 GALAXY HIGH REDSHIFT GALAXY K=19.2 J2000 23 46 9.4280 +12 49 19.21 J2000 GALAXY HIGH REDSHIFT GALAXY J2000 23 48 12.9690 +00 25 46.34 J2000 NIC2 Imaging No No F160W NIC2 Imaging No No F160W NIC2 Imaging No No F160W NIC2 Imaging No No F160W NIC2 Imaging No No F160W NIC2 Imaging No No F160W NIC2 Imaging No No F160W POS-TARG DITHER DITHER 1.5375 NIC-XSTRIP-DITH false false 4 0 POS-TARG NIC-SPIRAL-DITH 0 1 false (Tic-Visit :proposal-id 10924 :visit-id "01" :proposal-version -1 :trans-version "20060322" :date "30-Apr-2006 15:21:17.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5236608 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10924 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10924 :visit-id "01" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2782 :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 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "01" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2774 :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 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "01" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2754 :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 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "01" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2731 :al-overhead-at-end 0 :internal-dur-at-end 491 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) false 4 0 Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. (Tic-Visit :proposal-id 10924 :visit-id "02" :proposal-version -1 :trans-version "20060322" :date "30-Apr-2006 15:22:22.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5236608 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10924 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10924 :visit-id "02" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2782 :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 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "02" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2774 :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 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "02" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2754 :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 3149 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "02" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2731 :al-overhead-at-end 0 :internal-dur-at-end 491 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3149 :pcs-gap 0 ) false 4 0 Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. (Tic-Visit :proposal-id 10924 :visit-id "03" :proposal-version -1 :trans-version "20060322" :date "30-Apr-2006 15:28:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5806400 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10924 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10924 :visit-id "03" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2802 :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 3243 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "03" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2882 :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 3243 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "03" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2882 :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 3243 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "03" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2859 :al-overhead-at-end 0 :internal-dur-at-end 490 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3243 :pcs-gap 0 ) false 4 0 Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. (Tic-Visit :proposal-id 10924 :visit-id "04" :proposal-version -1 :trans-version "20060322" :date "30-Apr-2006 15:27:09.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5236608 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10924 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10924 :visit-id "04" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2777 :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 3132 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "04" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2754 :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 3132 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "04" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2754 :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 3132 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "04" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2731 :al-overhead-at-end 0 :internal-dur-at-end 491 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 4 0 Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. (Tic-Visit :proposal-id 10924 :visit-id "05" :proposal-version -1 :trans-version "20060322" :date "30-Apr-2006 15:53:36.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5236608 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10924 :visit-id "05" :obset-id "05" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10924 :visit-id "05" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2782 :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 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "05" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2774 :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 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "05" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2754 :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 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "05" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2731 :al-overhead-at-end 0 :internal-dur-at-end 491 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) false 4 0 Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. (Tic-Visit :proposal-id 10924 :visit-id "06" :proposal-version -1 :trans-version "20060322" :date "30-Apr-2006 15:24:52.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5236608 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10924 :visit-id "06" :obset-id "06" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10924 :visit-id "06" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2782 :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 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "06" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2774 :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 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "06" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2754 :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 3137 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "06" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2731 :al-overhead-at-end 0 :internal-dur-at-end 491 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3137 :pcs-gap 0 ) false 4 0 Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. (Tic-Visit :proposal-id 10924 :visit-id "07" :proposal-version -1 :trans-version "20060322" :date "30-Apr-2006 15:25:59.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 4 :saa-model "23" :si-bright-earth-limb-angle 20.0 :data-volume 5236608 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10924 :visit-id "07" :obset-id "07" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10924 :visit-id "07" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2772 :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 3132 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "07" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2774 :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 3132 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "07" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2754 :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 3132 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10924 :visit-id "07" :orbit-number 4 :pcs-time 355 :si-vis-utilization 2731 :al-overhead-at-end 0 :internal-dur-at-end 491 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3132 :pcs-gap 0 ) false 4 0 Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA. Since primary NIC2 observations are long exposures of faint galaxy targets, please do not schedule right after passage through SAA.