HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science



DAILY REPORT #4925



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 3x3 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 1x1, 1x2,

2x1, and 2x2 bin settings at gain=1, and 1x1 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)