NASA Hubble Space Telescope Daily Report #4925
HUBBLE SPACE TELESCOPE DAILY REPORT #4925
Continuing to Collect World Class Science
PERIOD COVERED: 5am September 4 – 5am September 8, 2009 (DOY 247/09:00z-251/09:00z)
OBSERVATIONS SCHEDULED
WFC3/UVIS 11935
UVIS G280 Wavelength Calibration
Wavelength calibration of the UVIS G280 grism will be established using observations of the Wolf Rayet star WR14. Accompanying direct exposures will provide wavelength zeropoints for dispersed exposures. The calibrations will be obtained at the central position of each CCD chip and at the center of the UVIS field. No additional field- dependent variations will be obtained.
WFC3/IR/S/C 11929
IR Dark Current Monitor
Analyses of ground test data showed that dark current signals are more reliably removed from science data using darks taken with the same exposure sequences as the science data, than with a single dark current image scaled by desired exposure time. Therefore, dark current images must be collected using all sample sequences that will be used in science observations. These observations will be used to monitor changes in the dark current of the WFC3-IR channel on a day-to-day basis, and to build calibration dark current ramps for each of the sample sequences to be used by GOs in Cycle 17. For each sample sequence/array size combination, a median ramp will be created and delivered to the calibration database system (CDBS).
WFC3/UVIS 11912
UVIS Internal Flats
This proposal will be used to assess the stability of the flat field structure for the UVIS detector throughout the 15 months of Cycle 17. The data will be used to generate on- orbit updates for the delta-flat field reference files used in the WFC3 calibration pipeline, if significant changes in the flat structure are seen.
WFC3/UVIS 11908
Cycle 17: UVIS Bowtie Monitor
Ground testing revealed an intermittent hysteresis type effect in the UVIS detector (both CCDs) at the level of ~1%, lasting hours to days. Initially found via an unexpected bowtie-shaped feature in flatfield ratios, subsequent lab tests on similar e2v devices have since shown that it is also present as simply an overall offset across the entire CCD, i.e., a QE offset without any discernable pattern. These lab tests have further revealed that overexposing the detector to count levels several times full well fills the traps and effectively neutralizes the bowtie. Each visit in this proposal acquires a set of three 3×3 binned internal flatfields: the first unsaturated image will be used to detect any bowtie, the second, highly exposed image will neutralize the bowtie if it is present, and the final image will allow for verification that the bowtie is gone.
WFC3/UVIS 11907
UVIS Cycle 17 Contamination Monitor
The UV throughput of WFC3 during Cycle 17 is monitored via weekly standard star observations in a subset of key filters covering 200-600nm and F606W, F814W as controls on the red end. The data will provide a measure of throughput levels as a function of time and wavelength, allowing for detection of the presence of possible contaminants.
WFC3/UVIS 11905
WFC3 UVIS CCD Daily Monitor
The behavior of the WFC3 UVIS CCD will be monitored daily with a set of full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K subarray biases are acquired at less frequent intervals throughout the cycle to support subarray science observations. The internals from this proposal, along with those from the anneal procedure (Proposal 11909), will be used to generate the necessary superbias and superdark reference files for the calibration pipeline (CDBS).
COS/NUV 11896
NUV Spectroscopic Sensitivity Monitoring
The purpose of this proposal is to monitor sensitivity of each NUV grating mode to detect any changes due to contamination or other causes.
ACS/WFC3 11879
CCD Daily Monitor (Part 1)
This program comprises basic tests for measuring the read noise and dark current of the ACS WFC and for tracking the growth of hot pixels. The recorded frames are used to create bias and dark reference images for science data reduction and calibration. This program will be executed four days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To facilitate scheduling, this program is split into three proposals. This proposal covers 352 orbits (22 weeks) from 31 August 2009 to 31 January 2010.
WFC3/ACS/UVIS 11877
HST Cycle 17 and Post-SM4 Optical Monitor
This program is the Cycle 17 implementation of the HST Optical Monitoring Program.
The 36 orbits comprising this proposal will utilize ACS (Wide Field Channel) and WFC3 (UVIS Channel) to observe stellar cluster members in parallel with multiple exposures over an orbit. Phase retrieval performed on the PSF in each image will be used to measure primarily focus, with the ability to explore apparent coma, and astigmatism changes in WFC3.
The goals of this program are to: 1) monitor the overall OTA focal length for the purposes of maintaining focus within science tolerances 2) gain experience with the relative effectiveness of phase retrieval on WFC3/UVIS PSFs 3) determine focus offset between the imagers and identify any SI-specific focus behavior and dependencies
If need is determined, future visits will be modified to interleave WFC3/IR channel and STIS/CCD focii measurements.
STIS/CCD 11855
STIS/CCD Spectroscopic Sensitivity Monitor for Cycle 17
The purpose of this proposal is to monitor the sensitivity of each CCD grating mode to detect any changes due to contamination or other causes.
STIS/CCD 11850
CCD Sparse Field CTE Internal
CTE measurements are made using the “internal sparse field test”, along the parallel axis. The “Pos=” optional parameter, introduced during Cycle 11, is used to provide off- center MSM positionings of some slits. All exposures are internals.
STIS/CCD 11849
STIS CCD Hot Pixel Annealing
This purpose of this activity is to repair radiation induced hot pixel damage to the STIS CCD by warming the CCD to the ambient instrument temperature and annealing radiation-damaged pixels.
Radiation damage creates hot pixels in the STIS CCD Detector. Many of these hot pixels can be repaired by warming the CCD from its normal operating temperature near – 83 deg. C to the ambient instrument temperature (~ +5 deg. C) for several hours. The number of hot pixels repaired is a function of annealing temperature. The effectiveness of the CCD hot pixel annealing process is assessed by measuring the dark current behavior before and after annealing and by searching for any window contamination effects.
STIS/CCD 11846
CCD Bias Monitor-Part 1
The purpose of this proposal is to monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns.
STIS/CCD 11844
CCD Dark Monitor Part 1
The purpose of this proposal is to monitor the darks for the STIS CCD.
FGS 11706
The Parallax of the Planet Host Star XO-3
We will use HST+FGS to measure the parallax of the transiting planet host star XO 3. The resulting accurate distance measurement will provide the most accurate radius determination to date for this massive extrasolar planet (XO-3B), allowing us to critically test current giant extrasolar planet structure models. These observations will also constrain the amount of heating that may be produced inside XO-3B by tides raised on the planet as it moves through its 3.2 d-eccentric (e ~ 0.22) orbit.
WFC3/UVIS 11657
The Population of Compact Planetary Nebulae in the Galactic Disk
We propose to secure narrow- and broad-band images of compact planetary nebulae (PNe) in the Galactic Disk to study the missing link of the early phases of post-AGB evolution. Ejected AGB envelopes become PNe when the gas is ionized. PNe expand, and, when large enough, can be studied in detail from the ground. In the interim, only the HST capabilities can resolve their size, morphology, and central stars. Our proposed observations will be the basis for a systematic study of the onset of morphology. Dust properties of the proposed targets will be available through approved Spitzer/IRS spectra, and so will the abundances of the alpha-elements. We will be able thus to explore the interconnection of morphology, dust grains, stellar evolution, and populations. The target selection is suitable to explore the nebular and stellar properties across the Galactic Disk, and to set constraints on the galactic evolutionary models through the analysis of metallicity and population gradients.
WFC3/UVIS 11650
Mutual Orbits, Colors, Masses, and Bulk Densities of 3 Cold Classical Trans-Neptunian
Many trans-neptunian objects (TNOs) have been found to be binary or multiple systems. As in other astrophysical settings, trans-neptunian binaries (TNBs) offer uniquely valuable information. Their mutual orbits allow the direct determination of their system masses, perhaps the most fundamental physical quantity of any astronomical object. Their frequency of occurrence and dynamical characteristics provide clues to formation conditions and evolution scenarios affecting both the binaries and their single neighbors. Combining masses with sizes, bulk densities can be measured. Densities constrain bulk composition and internal structure, key clues to TNO origins and evolution over time. Several TNB bulk densities have been determined, hinting at interesting trends. But none of them belongs to the Cold Classical sub-population, the one group of TNOs with demonstrably distinct physical characteristics. Two top-priority Spitzer programs will soon observe and measure the sizes of 3 Cold Classical TNBs. This proposal seeks to determine the mutual orbits and thus masses of these systems, enabling computation of their densities.
WFC3/UVIS/IR 11644
A Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into the Formation of the Outer Solar System
The eight planets overwhelmingly dominate the solar system by mass, but their small numbers, coupled with their stochastic pasts, make it impossible to construct a unique formation history from the dynamical or compositional characteristics of them alone. In contrast, the huge numbers of small bodies scattered throughout and even beyond the planets, while insignificant by mass, provide an almost unlimited number of probes of the statistical conditions, history, and interactions in the solar system. To date, attempts to understand the formation and evolution of the Kuiper Belt have largely been dynamical simulations where a hypothesized starting condition is evolved under the gravitational influence of the early giant planets and an attempt is made to reproduce the current observed populations. With little compositional information known for the real Kuiper Belt, the test particles in the simulation are free to have any formation location and history as long as they end at the correct point. Allowing compositional information to guide and constrain the formation, thermal, and collisional histories of these objects would add an entire new dimension to our understanding of the evolution of the outer solar system. While ground based compositional studies have hit their flux limits already with only a few objects sampled, we propose to exploit the new capabilities of WFC3 to perform the first ever large-scale dynamical-compositional study of Kuiper Belt Objects (KBOs) and their progeny to study the chemical, dynamical, and collisional history of the region of the giant planets. The sensitivity of the WFC3 observations will allow us to go up to two magnitudes deeper than our ground based studies, allowing us the capability of optimally selecting a target list for a large survey rather than simply taking the few objects that can be measured, as we have had to do to date. We have carefully constructed a sample of 120 objects which provides both overall breadth, for a general understanding of these objects, plus a large enough number of objects in the individual dynamical subclass to allow detailed comparison between and within these groups. These objects will likely define the core Kuiper Belt compositional sample for years to come. While we have many specific results anticipated to come from this survey, as with any project where the field is rich, our current knowledge level is low, and a new instrument suddenly appears which can exploit vastly larger segments of the population, the potential for discovery — both anticipated and not — is extraordinary.
WFC3/UVIS 11594
A WFC3 Grism Survey for Lyman Limit Absorption at z=2
We propose to conduct a spectroscopic survey of Lyman limit absorbers at redshifts 1.8 < z < 2.5, using WFC3 and the G280 grism. This proposal intends to complete an approved Cycle 15 SNAP program (#10878) which was cut short due to the ACS failure. We have selected 64 quasars at 2.3 < z < 2.6 from the Sloan Digital Sky Survey Spectroscopic Quasar Sample, for which no BAL signature is found at the QSO redshift and no strong metal absorption lines are present at z > 2.3 along the lines of sight. The survey has three main
observational goals. First, we will determine the redshift frequency dn/dz of the LLS over the column density range 16.0 < log(NHI) < 20.3 cm^-2. Second, we will measure the column density frequency distribution f(N) for the partial Lyman limit systems (PLLS) over the column density range 16.0 < log(NHI) < 17.5 cm^-2. Third, we will identify those sightlines which could provide a measurement of the primordial D/H ratio. By carrying out this survey, we can also help place meaningful constraints on two key quantities of cosmological relevance. First, we will estimate the amount of metals in the LLS using the f(N), and ground based observations of metal line transitions. Second, by determining f(N) of the PLLS, we can constrain the amplitude of the ionizing UV background at z~2 to a greater precision. This survey is ideal for a snapshot observing program, because the on-object integration times are all well below 30 minutes, and follow-up observations from the ground require minimal telescope time due to the QSO sample being bright. WFC3/ACS/IR 11584 Resolving the Smallest Galaxies with ACS An order of magnitude more dwarf galaxies are expected to inhabit the Local Group, based on currently accepted galaxy formation models, than have been observed. This discrepancy has been noted in environments ranging from the field to rich clusters, with evidence emerging that lower density regions contain fewer dwarfs per giant than higher density regions, in further contrast to model predictions. However, there is no complete census of the faintest dwarf galaxies in any environment. The discovery of the smallest and faintest dwarfs is hampered by the limitations in detecting such compact or low surface brightness galaxies, and this is compounded by the great difficulty in determining accurate distances to, or ascertaining group membership for, such faint objects. The M81 group provides a powerful means for establishing membership for faint galaxies in a low density region. With a distance modulus of 27.8, the tip of the red giant branch (TRGB) appears at I ~ 24, just within the reach of ground based surveys. We have completed a 65 square degree survey in the region around M81 with the CFHT/MegaCam. Half of our survey was completed before Cycle 16 and we were awarded time with WFPC2 to observe 15 new candidate dwarf galaxy group members in F606W and F814W bands in order to construct color-magnitude diagrams from which to measure accurate TRGB distances and determine star formation and metallicity histories. The data obtained show that 8 – 9 of these objects are galaxies at the same distance as M81. In completing our survey, we have discovered an additional 8 candidate galaxies we propose to image with ACS in order to measure TRGB distances and establish membership. We also wish to re-observe our smallest candidate group member and a tidal dwarf candidate with deeper observations made possible with ACS. Once membership has been established for this second set of candidates, we will have a complete census of the dwarf galaxy population in the M8 group to M_r ~ -10, allowing us to obtain a firm measurement of the luminosity function faint-end slope, and, combined with previous HST data, to provide a complete inventory of the age and abundance properties for the collapsed core of the M81 group. WFC3/ACS/IR 11563 Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to <0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields The first generations of galaxies were assembled around redshifts z~7-10+, just 500-800 Myr after recombination, in the heart of the reionization of the universe. We know very little about galaxies in this period. Despite great effort with HST and other telescopes, less than ~15 galaxies have been reliably detected so far at z>7, contrasting with the ~1000 galaxies detected to date at z~6, just 200-400 Myr later, near the end of the reionization epoch. WFC3 IR can dramatically change this situation, enabling derivation of the galaxy luminosity function and its shape at z~7-8 to well below L*, measurement of the UV luminosity density at z~7-8 and z~8-9, and estimates of the contribution of galaxies to reionization at these epochs, as well as characterization of their properties (sizes, structure, colors). A quantitative leap in our understanding of early galaxies, and the timescales of their buildup, requires a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can achieve this with 192 WFC3 IR orbits on three disjoint fields (minimizing cosmic variance): the HUDF and the two nearby deep fields of the HUDF05. Our program uses three WFC3 IR filters, and leverages over 600 orbits of existing ACS data, to identify, with low contamination, a large sample of over 100 objects at z~7-8, a very useful sample of ~23 at z~8-9, and limits at z~10. By careful placement of the WFC3 IR and parallel ACS pointings, we also enhance the optical ACS imaging on the HUDF and a HUDF05 field. We stress (1) the need to go deep, which is paramount to define L*, the shape, and the slope alpha of the luminosity function (LF) at these high redshifts; and (2) the far superior performance of our strategy, compared with the use of strong lensing clusters, in detecting significant samples of faint z~7-8 galaxies to derive their luminosity function and UV ionizing flux. Our recent z~7.4 NICMOS results show that wide-area IR surveys, even of GOODS-like depth, simply do not reach faint enough at z~7-9 to meet the LF and UV flux objectives. In the spirit of the HDF and the HUDF, we will waive any proprietary period, and will also deliver the reduced data to STScI. The proposed data will provide a Legacy resource of great value for a wide range of archival science investigations of galaxies at redshifts z~2-9. The data are likely to remain the deepest IR/optical images until JWST is launched, and will provide sources for spectroscopic followup by JWST, ALMA and EVLA.
COS/FUV 11491
COS FUV External Flat Fields
Obtain external spectra of flat field targets at different positions along the cross- dispersion direction of the FUV detector (and at a variety of FP-POS positions) in order to obtain an FUV flat field. The choices of gratings and positions of the target in the aperture have been made in order to maximize the coverage on the detector in the cross-dispersion direction and cover the entire region where science spectra will fall.
COS/FUV 11490
COS FUV External Spectroscopic Performance – Part 2
The goal of this activity is to verify the spatial resolution of COS in the FUV and to characterize the interdependence of the spatial and spectral resolution of the instrument in that wavelength band. By stepping the source along the cross-dispersion direction out to the edge of the PSA, we will be able to quantify the variation of the spatial profile of the source with off-axis position, both by measuring the shape and width of the profile and by measuring the amount of flux transmitted through the aperture as the source is stepped past the edge of the aperture. Aside from measuring the spatial resolution of COS spectra, this study will be particularly useful for understanding the contamination of sources near the targeted object in crowded stellar fields.
This test is ideally performed with a spatially unresolved point source with an emission line spectrum. Our observations with the PSA will target the symbiotic star LIN 358 in the Large Magellanic Cloud. This star produces little or no continuum in the FUV, but exhibits line emission from He II (particularly strong), C IV, N IV and N V. The individual lines are unresolved in FOS spectra of this object, but the lines within the C IV and N V doublets are well resolved from one another. This indicates that the emission lines in the COS observations are likely to be narrow (<~ 60 km/s). These observations will implement the following procedure: First, a target acquisition is performed to place the target at the center of the aperture. For each FUV grating we obtain moderately high S/N (~ 30 per resel counting statistics) observations at one central wavelength setting with the PSA. Next we repeat the sequence of observations at each of five additional positions, with offsets of 0.25, 0.5, 1.0, 1.5, and 1.75 arcseconds in the cross-dispersion (Y) direction from the center of the aperture. The procedure is then repeated for five more POSTARGs offset in the negative cross-dispersion direction (-Y). This results in a total of 11 exposures with the G130M and G140L gratings. For observations with the G160M grating we include an additional set of 5 POSTARGs each along the positive (+X) and negative (-X) dispersion directions. The goal of these observations is to test variations in the shape and width of the profile along the dispersion direction, and to compare the results with those from the cross-dispersion direction. All of these observations will be performed in Time-Tag mode with Flash=Yes for all three FUV gratings, but with FP-POS set to the default value of 3. The observations with the BOA will be performed on the Galactic symbiotic star AG Draconis (M_V = 9.8). This object is a bright recurrent nova (period ~ 15 yrs) and a source of strong ultraviolet line emission. Here we obtain a single Time-Tag exposure for each of the four FUV gratings with the object centered in the BOA to evaluate the spatial resolution in this mode. We aim for S/N = 20 for the brightest emission line in each observation. The number of exposures in this program is somewhat larger than the number described in the Activity Summary, but is necessary to perform the intended tests of the COS spectral resolution. This activity is SMOV program COS 32. Implementation Method: Stored Commanding Data Requirements: Approximately 420 MB Dependencies: Execute after verification based upon results of Activity COS 30 (Internal FUV Wavelength Calibration) (SMOV Proposal 11488) Applicable SMOV Requirements: L.10.4.2.3.12.2; L.10.4.2.3.12.3; L.10.4.2.3.13 COS/FUV 11482 FUV Detector Dark Measure the FUV detector dark rate by taking long science exposures with no light on the detector. The detector dark rate and spatial distribution of counts will be compared to pre-launch data in order to verify the nominal operation of the detector, and for use in the CalCOS calibration pipeline. Variations of count rate as a function of orbital position will be analyzed to find dependence of dark rate on proximity to the SAA. This is SMOV Activity COS-24. COS/NUV 11477 COS NUV External Spectroscopic Performance – Part 2 The goal of this activity is to verify the spatial resolution of COS in the NUV and to characterize the interdependence of the spatial and spectral resolution of the instrument in that wavelength band. By stepping the source along the cross-dispersion direction out to the edge of the PSA, we will be able to quantify the variation of the spatial profile of the source with off-axis position, both by measuring the shape and width of the profile and by measuring the amount of flux transmitted through the aperture as the source is stepped past the edge of the aperture. Aside from measuring the spatial resolution of COS spectra, this study will be particularly useful for characterizing the contamination of sources near the targeted object in crowded stellar fields. This test is ideally performed with a spatially unresolved point source with an emission line spectrum. Our observations with the PSA will target the Galactic symbiotic stars AG Draconis and He 2-38. The former object produces a low, nearly flat NUV continuum and exhibits line emission from He II (particularly strong), N III], Si III] and Bowen fluorescence line emission from OIII]. The lines are well resolved in existing STIS echelle spectra of this object, where they exhibit line widths ranging from 40 km/s to 60 km/s. We expect similar line widths in our COS observations. He 2-38, on the other hand, is considerably fainter than AG Dra in the NUV, due to presence of a dust shell around the source (it is a Mira-type system). The reddening toward He 2-38 is also considerable (E(B -V)=1.2). Our observations with the BOA will target another Galactic symbiotic star, RR Telescopii. This object exhibits similar line widths to AG Dra, but includes a rich array of Fe II emission lines as well. These observations will implement the following procedure: First, a target acquisition is performed to place the target at the center of the aperture. For each NUV grating we obtain moderately high S/N (~ 30 per resel counting statistics) observations at one central wavelength setting with the PSA. Next we repeat the sequence of observations at each of 5 additional positions, with offsets of 0.25, 0.5, 1.0, 1.5 and 1.75 arcseconds in the cross-dispersion direction (+Y). The procedure is repeated for 5 more POSTARGs offset in the negative cross-dispersion direction (-Y). This results in a total of 11 exposures with the G225M and G285M gratings. For observations with the G185M grating we include an additional set of 5 POSTARGs each along the positive (+X) and negative (-X) dispersion directions. The goal of these observations is to test variations in the shape and width of the profile along the dispersion direction. All of these observations will be performed in Time-Tag mode with Flash=Yes for all four NUV gratings, but with FP-POS simply set to the default value of 3. Our G230L observations will target He 2-38, and will be performed with the same set of offsets (11) as the G185M and G225M gratings. We plan to perform additional NUV observations through the BOA of the symbiotic star RR Tel, where we will obtain a single TIME-TAG exposure for each of the four NUV gratings with the object centered in the BOA to evaluate the spatial resolution in this mode. We aim for S/N >= 20 in these observations.
This activity is SMOV Program COS 17.
Implementation Method: Stored Commanding
Data Requirements: Approximately 420 MB
Dependencies: Execute after verification based upon results of Activity COS 15 (Internal NUV Wavelength Verification) (SMOV Program 11475).
Applicable SMOV Requirements: L.10.4.2.3.7.2; L.10.4.2.3.7.3; L.10.4.2.3.13
STIS20 11402
STIS-20 NUV MAMA Dark Monitor
The STIS NUV-MAMA dark current is dominated by a phosphorescent glow from the detector window. Meta-stable states in this window are populated by cosmic ray impacts, which, days later, can be thermally excited to an unstable state from which they decay, emitting a UV photon. The equilibrium population of these meta-stable states is larger at lower temperatures; so warming up the detector from its cold safing will lead to a large, but temporary, increase in the dark current.
To monitor the decay of this glow, and to determine the equilibrium dark current for Cycle 17, four 1380s NUV-MAMA ACCUM mode darks should be taken each week during the SMOV period. Once the observed dark current has reached an approximate equilibrium with the mean detector temperature, the frequency of this monitor can be reduced to one pair of darks per week.
WFC3/ACS/IR 11235
HST NICMOS Survey of the Nuclear Regions of Luminous Infrared Galaxies in the Local Universe
At luminosities above 10^11.4 L_sun, the space density of far-infrared selected galaxies exceeds that of optically selected galaxies. These `luminous infrared galaxies’ (LIRGs) are primarily interacting or merging disk galaxies undergoing enhanced star formation and Active Galactic Nuclei (AGN) activity, possibly triggered as the objects transform into massive S0 and elliptical merger remnants. We propose NICMOS NIC2 imaging of the nuclear regions of a complete sample of 88 L_IR > 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample (RBGS: i.e., 60 micron flux density > 5.24 Jy). This sample is ideal not only in its completeness and sample size, but also in the proximity and brightness of the galaxies. The superb sensitivity and resolution of NICMOS NIC2 on HST enables a unique opportunity to study the detailed structure of the nuclear regions, where dust obscuration may mask star clusters, AGN, and additional nuclei from optical view, with a resolution significantly higher than possible with Spitzer IRAC. This survey thus provides a crucial component to our study of the dynamics and evolution of IR galaxies presently underway with Wide-Field, HST ACS/WFC3, and Spitzer IRAC observations of these 88 galaxies. Imaging will be done with the F160W filter (H-band) to examine as a function of both luminosity and merger stage: (i) the luminosity and distribution of embedded star clusters, (ii) the presence of optically obscured AGN and nuclei, (iii) the correlation between the distribution of 1.6 micron emission and the mid-IR emission as detected by Spitzer IRAC, (iv) the evidence of bars or bridges that may funnel fuel into the nuclear region, and (v) the ages of star clusters for which photometry is available via ACS/WFC3 observations. The NICMOS data, combined with the HST ACS, Spitzer, and GALEX observations of this sample, will result in the most comprehensive study of merging and interacting galaxies to date.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS: (None)
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSAcq 34 34
FGS REAcq 29 29
OBAD with Maneuver 29 29
SIGNIFICANT EVENTS: (None)
