HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT      # 4508

PERIOD COVERED: UT December 14,15,16, 2007 (DOY 348,349,350)

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8795

NICMOS Post-SAA calibration - CR Persistence Part 6

A new procedure proposed to alleviate the CR-persistence problem of

NICMOS. Dark frames will be obtained immediately upon exiting the SAA

contour 23, and every time a NICMOS exposure is scheduled within 50

minutes of coming out of the SAA. The darks will be obtained in parallel

in all three NICMOS Cameras. The POST-SAA darks will be non- standard

reference files available to users with a USEAFTER date/time mark. The

keyword 'USEAFTER=date/time' will also be added to the header of each

POST-SAA DARK frame. The keyword must be populated with the time, in

addition to the date, because HST crosses the SAA ~8 times per day so

each POST-SAA DARK will need to have the appropriate time specified, for

users to identify the ones they need. Both the raw and processed images

will be archived as POST-SAA DARKSs. Generally we expect that all NICMOS

science/calibration observations started within 50 minutes of leaving an

SAA will need such maps to remove the CR persistence from the science i

mages. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.

FGS 11462

FGS1r, FGS2r, and FGS3 Pre-SM4 Performance

This proposal is the first of a pair of proposals that monitors the

characteristics of HST's two " continuing" Fine Guidance Sensors across

the boundary of the servicing mission SM4. This proposal obtains the

pre-SM4 measurements. Proposal 11463 gathers the same data but for the

post-SM4 baseline. For each FGS, stars from a selected field in the

standard astrometric Galactic cluster M35 are observed in Position mode.

This provides a measurement of their relative positions, which in turn

provides an effective means to detect and monitor any changes in the FGS

optical distortions and plate scales. If out of tolerance, the need for a

re- calibration of the particular FGS's distortions will be indicated.

The FGS-FGS alignments will also be monitored across the SM boundary.

This will be done by using the same guide star pairs in the

corrresponding proposal 11463. Finally, this proposal and 11463 include

Transfer mode observations of selected M35 stars. These observations

will obtain S-curves at the center and at two off-center field points in

each FGS FOV. These data will provide insight as to whether or not the

relative alignment of the FGS optical train with the HST OTA has

changed. If changes larger than tolerance are observed, it will be

necessary to activate the appropriate contingency proposal that will

obtain S-curves are several locations in the FGS FOV to facilitate a

re-computation of the optimal values of K-factors that are used in the

acquisition and tracking of guide stars (and astrometry targets). This

proposal requires a total of 4 HST orbit to support the FGS2r and FGS3

observations. The FGS1r observations are available from the FGS Cycle 16

Astrometry calibration plan.

FGS 11315

Monitoring FGS1r's Interferometric Response as a Function of Spectral

Color

This proposal uses FGS1r in Transfer mode to observe single stars to

obtain the interference fringes of point sources. These data are used by

FGS data analysis tools for studying binary and hierarchical multiple

star systems. Visit 01 observes three stars in M35 over the FGS1r FOV as

a precursor to a corresponding visit in FGS/SM4 proposal 11463.

NIC3 11306

Direct radius measurement of the Neptune-size transiting exoplanet

GJ436b

We propose to measure the radius of the first transiting Neptune-class

extrasolar planet, GJ 436b. The transits of this 22-Earth-mass planet

around a nearby M dwarf were recently detected by our team. Ground-based

photometric observations indicate a planet size compatible with a

Neptune-like structure or an "Ocean Planet". A direct radius

determination from an HST infrared lightcurve will provide a much more

direct measurement of the radius and density of the planet. GJ 436b is

the nearest known transiting exoplanet, as well as the smallest and

lightest, by a large margin. The high planet-to-star contrast in the

infrared make it very favorable for detailed studies. NICMOS 1-2 microns

observations, in addition to measuring its size, may reveal water

absorption from its outer atmosphere.

ACS/SBC 11215

New Sightlines for the Study of Intergalactic Helium: Dozens of

High-Confidence, UV-Bright Quasars from SDSS/GALEX

The reionization of IGM helium is thought to have occurred at redshifts

of z=3 to 4. Detailed study of HeII Lyman-alpha absorption toward a

handful of QSOs at 2.7<z<3.3 demonstrated the high potential of such IGM

probes, but the critically small sample size limits confidence in

cosmological inferences. The requisite unobscured sightlines to high-z

are extremely rare, but SDSS provides 5800, z>3.1 QSOs potentially

suitable for HeII studies. We've cross-correlated SDSS quasars with

GALEX UV sources to obtain dozens of new, high confidence, candidate

sightlines {z=3.1-4.9} potentially useful for detailed HeII studies with

HST. We propose brief, 2-orbit reconnaissance ACS SBC prism exposures

toward each of the best dozen new quasars, to definitively verify UV

flux down to HeII. Our combined SDSS/GALEX selection insures a high

confirmation rate, as the quasars are already known to be UV bright in

GALEX. Our program will provide a statistical sample of HeII sightlines

extending to high redshift, enabling future long exposure follow-up

spectra with the SBC prism, or superb quality COS or STIS spectra after

SM4. Stacks of our prism spectra will also directly yield ensemble

information. Ultimately, the new sightlines will enable confident

measures of the spectrum and evolution of the ionizing background, the

evolution of HeII opacity, the epoch of helium reionization, and the

density of IGM baryons.

FGS 11213

Distances to Eclipsing M Dwarf Binaries

We propose HST FGS observations to measure accurate distances of 5

nearby M dwarf eclipsing binary systems, from which model-independent

luminosities can be calculated. These objects have either poor or no

existing parallax measurements. FGS parallax determinations for these

systems, with their existing dynamic masses determined to better than

0.5%, would serve as model-independent anchor points for the low-mass

end of the mass-luminosity diagram.

FGS 11211

An Astrometric Calibration of Population II Distance Indicators

In 2002 HST produced a highly precise parallax for RR Lyrae. That

measurement resulted in an absolute magnitude, M{V}= 0.61+/-0.11, a

useful result, judged by the over ten refereed citations each year

since. It is, however, unsatisfactory to have the direct,

parallax-based, distance scale of Population II variables based on a

single star. We propose, therefore, to obtain the parallaxes of four

additional RR Lyrae stars and two Population II Cepheids, or W Vir

stars. The Population II Cepheids lie with the RR Lyrae stars on a

common K-band Period-Luminosity relation. Using these parallaxes to

inform that relationship, we anticipate a zero-point error of 0.04

magnitude. This result should greatly strengthen confidence in the

Population II distance scale and increase our understanding of RR Lyrae

star and Pop II Cepheid astrophysics.

WFPC2/NIC2 11193

A comprehensive study of the low-mass stellar population in the Galactic

starburst region NGC 3603

NGC 3603, located in the Carina spiral arm, is one of the most luminous

giant HII regions in the Milky Way, and as such it is often referred to

as a prime template for extragalactic starbursts. While previous studies

were focusing on the high and intermediate mass stellar content of the

central starburst cluster, which powers the HII region, the effects of

the starburst environment with its large number of ionizing O stars on

the emerging low-mass population are unknown. As the most nearby, most

easily accessible starburst, NGC 3603 provides the best testbed to study

the long-lived, low-mass stars originating from a starburst environment.

Taking advantage of the large field of view and high sensitivity of

WFPC2, we want to survey the stellar population in an area of 10pc x

10pc {6' x 6'} down to a mass limit of 0.2 to 0.5 Mo. This will enable

us to derive the total cluster mass, look for spatial variations in the

initial mass function, determine the age of the dispersed low-mass

population in the HII region and search for evidence of sequential star

formation. Ultimately, we aim at reconstructing the low-mass stellar

initial mass function of the starburst epoch in NGC 3603, which in turn

will advance our understanding of extragalactic starburst phenomena and

the emerging low-mass stars as observed in ancient populations. The

observations of NGC 3603 are part of our larger effort to study intense

star-forming regions in the Milky Way, LMC and SMC.

WFPC2 11178

Probing Solar System History with Orbits, Masses, and Colors of

Transneptunian Binaries

The recent discovery of numerous transneptunian binaries {TNBs} opens a

window into dynamical conditions in the protoplanetary disk where they

formed as well as the history of subsequent events which sculpted the

outer Solar System and emplaced them onto their present day heliocentric

orbits. To date, at least 47 TNBs have been discovered, but only about a

dozen have had their mutual orbits and separate colors determined,

frustrating their use to investigate numerous important scientific

questions. The current shortage of data especially cripples scientific

investigations requiring statistical comparisons among the ensemble

characteristics. We propose to obtain sufficient astrometry and

photometry of 23 TNBs to compute their mutual orbits and system masses

and to determine separate primary and secondary colors, roughly tripling

the sample for which this information is known, as well as extending it

to include systems of two near-equal size bodies. To make the most

efficient possible use of HST, we will use a Monte Carlo technique to

optimally schedule our observations.

NIC3 11107

Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy

Formation in the Early Universe

We have used the ultraviolet all-sky imaging survey currently being

conducted by the Galaxy Evolution Explorer {GALEX} to identify for the

first time a rare population of low- redshift starbursts with properties

remarkably similar to high-redshift Lyman Break Galaxies {LBGs}. These

"compact UV luminous galaxies" {UVLGs} resemble LBGs in terms of size,

SFR, surface brightness, mass, metallicity, kinematics, dust, and color.

The UVLG sample offers the unique opportunity of investigating some very

important properties of LBGs that have remained virtually inaccessible

at high redshift: their morphology and the mechanism that drives their

star formation. Therefore, in Cycle 15 we have imaged 7 UVLGs using ACS

in order to 1} characterize their morphology and look for signs of

interactions and mergers, and 2} probe their star formation histories

over a variety of timescales. The images show a striking trend of

small-scale mergers turning large amounts of gas into vigorous

starbursts {a process referred to as dissipational or "wet" merging}.

Here, we propose to complete our sample of 31 LBG analogs using the

ACS/SBC F150LP {FUV} and WFPC2 F606W {R} filters in order to create a

statistical sample to study the mechanism that triggers star formation

in UVLGs and its implications for the nature of LBGs. Specifically, we

will 1} study the trend between galaxy merging and SFR in UVLGs, 2}

artificially redshift the FUV images to z=1-4 and compare morphologies

with those in similarly sized samples of LBGs at the same rest-frame

wavelengths in e.g. GOODS, UDF, and COSMOS, 3} determine the presence

and morphology of significant stellar mass in "pre-burst" stars, and 4}

study their immediate environment. Together with our Spitzer

{IRAC+MIPS}, GALEX, SDSS and radio data, the HST observations will form

a unique union of data that may for the first time shed light on how the

earliest major episodes of star formation in high redshift galaxies came

about. This proposal was adapted from an ACS HRC+WFC proposal to meet

the new Cycle 16 observing constraints, and can be carried out using the

ACS/SBC and WFPC2 without compromising our original science goals.

NIC3 11082

NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive

Galaxies, Galaxies Beyond Reionization, and the High Redshift Obscured

Universe

(uses ACS/SBC and WFPC2)

Deep near-infrared imaging provides the only avenue towards

understanding a host of astrophysical problems, including: finding

galaxies and AGN at z > 7, the evolution of the most massive galaxies,

the triggering of star formation in dusty galaxies, and revealing

properties of obscured AGN. As such, we propose to observe 60 selected

areas of the GOODS North and South fields with NICMOS Camera 3 in the

F160W band pointed at known massive M > 10^11 M_0 galaxies at z > 2

discovered through deep Spitzer imaging. The depth we will reach {26.5

AB at 5 sigma} in H_160 allows us to study the internal properties of

these galaxies, including their sizes and morphologies, and to

understand how scaling relations such as the Kormendy relationship

evolved. Although NIC3 is out of focus and undersampled, it is currently

our best opportunity to study these galaxies, while also sampling enough

area to perform a general NIR survey 1/3 the size of an ACS GOODS field.

These data will be a significant resource, invaluable for many other

science goals, including discovering high redshift galaxies at z > 7,

the evolution of galaxies onto the Hubble sequence, as well as examining

obscured AGN and dusty star formation at z > 1.5. The GOODS fields are

the natural location for HST to perform a deep NICMOS imaging program,

as extensive data from space and ground based observatories such as

Chandra, GALEX, Spitzer, NOAO, Keck, Subaru, VLT, JCMT, and the VLA are

currently available for these regions. Deep high-resolution

near-infrared observations are the one missing ingredient to this

survey, filling in an important gap to create the deepest, largest, and

most uniform data set for studying the faint and distant universe. The

importance of these images will increase with time as new facilities

come on line, most notably WFC3 and ALMA, and for the planning of future

JWST observations.

NIC3 11080

Exploring the Scaling Laws of Star Formation

As a variety of surveys of the local and distant Universe are

approaching a full census of galaxy populations, our attention needs to

turn towards understanding and quantifying the physical mechanisms that

trigger and regulate the large-scale star formation rates {SFRs} in

galaxies.

WFPC2 11037

Red Filters Closeout

This calibration program observes three very red stars {M, L, T dwarfs}

in the five reddest broad and medium filters {F785LP, F791W, F814W,

F850LP, and F1042M} on WF3 in order to allow cross-calibration to ACS,

and in future WFC3. The far-red QE curves will also be tested. Similar

observations on PC1 were made in WFPC2/CAL 10078 and 10366.

WFPC2 11022

WFPC2 Cycle 15 Decontaminations and Associated Observations

This proposal is for the WFPC2 decons. Also included are instrument

monitors tied to decons: photometric stability check, focus monitor,

pre- and post-decon internals {bias, intflats, kspots, & darks}, UV

throughput check, VISFLAT sweep, and internal UV flat check.

WFPC2 11020

Cycle 15 Focus Monitor

The focus of HST is measured primarily with ACS/HRC over full CVZ orbits

to obtain accurate mean focus values via a well sampled breathing curve.

Coma and astigmatism are also determined from the same data in order to

further understand orbital effects on image quality and optical

alignments. To monitor the stability of ACS to WFPC2 relative focii,

we've carried over from previous focus monitor programs parallel

observations taken with the two cameras at suitable orientations of

previously observed targets, and interspersed them with the HRC CVZ

visits.

FGS 10928

Calibrating Cosmological Chronometers: White Dwarf Masses

We propose to use HST/FGS1R to determine White Dwarf {WD} masses. The

unmatched resolving power of HST/FGS1R will be utilized to follow up

four selected WD binary pairs. This high precision obtained with

HST/FGS1R simply cannot be equaled by any ground based technique. This

proposed effort complements that done by CoI Nelan in which a sample of

WDs is being observed with HST/FGS1R. This proposal will dramatically

increase the number of WDs for which dynamical mass measurements are

possible, enabling a better calibration of the WD mass-radius relation,

cooling curves, initial to final mass relations, and ultimately giving

important clues to the star formation history of our Galaxy and the age

of its disk as well as in other galaxies.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and

highly non-uniform archive, making comprehensive comparative studies

among galaxies essentially impossible. We propose to secure HST's

lasting impact on the study of nearby galaxies by undertaking a

systematic, complete, and carefully crafted imaging survey of ALL

galaxies in the Local Universe outside the Local Group. The resulting

images will allow unprecedented measurements of: {1} the star formation

history {SFH} of a >100 Mpc^3 volume of the Universe with a time

resolution of Delta[log{t}]=0.25; {2} correlations between spatially

resolved SFHs and environment; {3} the structure and properties of thick

disks and stellar halos; and {4} the color distributions, sizes, and

specific frequencies of globular and disk clusters as a function of

galaxy mass and environment. To reach these goals, we will use a

combination of wide-field tiling and pointed deep imaging to obtain

uniform data on all 72 galaxies within a volume-limited sample extending

to ~3.5 Mpc, with an extension to the M81 group. For each galaxy, the

wide-field imaging will cover out to ~1.5 times the optical radius and

will reach photometric depths of at least 2 magnitudes below the tip of

the red giant branch throughout the limits of the survey volume. One

additional deep pointing per galaxy will reach SNR~10 for red clump

stars, sufficient to recover the ancient SFH from the color-magnitude

diagram. This proposal will produce photometric information for ~100

million stars {comparable to the number in the SDSS survey} and uniform

multi- color images of half a square degree of sky. The resulting

archive will establish the fundamental optical database for nearby

galaxies, in preparation for the shift of high- resolution imaging to

the near-infrared.

WFPC2 10877

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for

supernovae {SNe}, most notably our Lick Observatory Supernova Search

{LOSS}, have found hundreds of SNe, many of them in quite nearby

galaxies {cz < 4000 km/s}. Most of the objects were discovered before

maximum brightness, and have follow-up photometry and spectroscopy; they

include some of the best-studied SNe to date. We propose to conduct a

snapshot imaging survey of the sites of some of these nearby objects, to

obtain late-time photometry that {through the shape of the light and

color curves} will help reveal the origin of their lingering energy. The

images will also provide high-resolution information on the local

environments of SNe that are far superior to what we can procure from

the ground. For example, we will obtain color-color and color-magnitude

diagrams of stars in these SN sites, to determine the SN progenitor

masses and constraints on the reddening. Recovery of the SNe in the new

HST images will also allow us to actually pinpoint their progenitor

stars in cases where pre- explosion images exist in the HST archive.

This proposal is an extension of our successful Cycle 13 snapshot survey

with ACS. It is complementary to our Cycle 15 archival proposal, which

is a continuation of our long-standing program to use existing HST

images to glean information about SN environments.

NIC3 10874

Search for Extremely Faint z>7 Galaxy Population with Cosmic Lenses

Deep UDF/NICMOS observations find a significant decrease in the number

of galaxy candidates between redshift z=6 and 7, but the sample at z>7

is too small to draw conclusions. From our observations of 15 clusters

we have found a number of bright z- dropouts, aided by the lensing

amplification. We propose deep NICMOS observations of the best cases of

cluster centers where a rare combination of a significant lensing effect

and the richness in z-band dropouts in background may dramatically

increase the discovery rate. The NICMOS images will reach an

unprecendented depth of AB~27.8, or AB~30 in nonlensed intrinsic

magnitude, and may find many faint {~0.05L*} galaxies at z=7-10, at a

level that the UDF reaches for z~6 objects. We produce precision mass

distribution maps from weak-lensing models, which enable us to derive

the candidates' intrinsic magnitudes and their luminosity function. The

knowledge of such faint galaxy population at z>7 will facilitate the

models of the IGM reionization and future JWST planning.

ACS/SBC 10872

Lyman Continuum Emission in Galaxies at z=1.2

Lyman continuum photons produced in massive starbursts may have played a

dominant role in the reionization of the Universe. Starbursts are

important contributors to the ionizing metagalactic background at lower

redshifts as well. However, their contribution to the background depends

upon the fraction of ionizing radiation that escapes from the intrinsic

opacity of galaxies below the Lyman limit. Current surveys suggest

escape fractions of a few percent, up to 10%, with very few detections

{as opposed to upper limits} having been reported. No detections have

been reported in the epochs between z=0.1 and z=2. We propose to measure

the fraction of escaping Lyman continuum radiation from 15 luminous

z~1.2 galaxies in the GOODS fields. Using the tremendous sensitivity of

the ACS Solar- blind Channel, we will reach AB=30 mag., allowing us to

detect an escape fraction of 1%. We will correlate the amount of

escaping radiation with the photometric and morphological properties of

the galaxies. A non-detection in all sources would imply that QSOs

provide the overwhelming majority of ionizing radiation at z=1.3, and it

would strongly indicate that the properties of galaxies at higher

redshift have to be significantly different for galaxies to dominate

reionization. The deep FUV images will also be useful for extending the

FUV study of other galaxies in the GOODS fields.

WFPC2 10812

Space Motions for the Draco and Sextans Dwarf Spheroidal Galaxies

We will use the powerful astrometric capabilities of HST to measure

proper motions for the Draco and Sextans dwarf spheroidal galaxies that

will yield tangential velocities accurate to about 30 km/s. These two

galaxies are the last inside a galactocentric radius of 200~kpc without

measured proper motions. Knowing their orbits is critical for our

understanding of the low-luminosity satellites of the Milky Way. In

particular they are critical for understanding why Ursa Minor has

survived tidal disruption on its plunging orbit and how Carina formed a

large intermediate-age stellar population despite its small mass.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports

of potential non-nominal performance that will be investigated.)

HSTARS:

11100 - REACQ(2,1,2) fine lock backup on FGS 2

           REACQ(2,1,2) at 348/19:23:02 acquired in fine lock backup on FGS 2 only,

           with QF1STOPF and QSTOP flags set on FGS 1 at 19:27:37. No other flags

           were seen. Previous acquisition at 17:50:11 was successful.

11101 - GSAcq(2,3,2) failed to RGA Hold(gyro Control)

           GSAcq(2,3,2) scheduled at 349/19:15:18 - 19:23:23 failed to RGA Hold due

           to (QF2STOPF) stop flag indication on FGS-2 during acquisition walkdown.

           Scheduled Astrometry FGS1 did not attempt. Pre-acquisition OBADs had

           (RSS) values of 931.61 and 4.46 arcseconds.

           OBAD/MAP scheduled at 349/19:23:23 had 3-axis (RSS) value of 4.18

           arcseconds.

11102 - GSAcq(1,2,1) failed to RGA Hold

           At AOS (350/00:51:00) observed that GSAcq (1,2,1) scheduled from

           00:41:58 - 00:49:52 had failed to RGA Hold due to QSTOP & QF2STOPF flags

           on FGS 2. No 486 ESB messages were received. Due to LOS, the data from

           OBAD 1 is unavailable till an engineering data dump is performed. OBAD 2

           data showed the following results: V1 1.39, V2 4.19, V3 3.00, RSS 5.34.

           OBAD MAP at 01:38:52 showed the following results: V1 -2.38, V2 -11.86,

           V3 9.58, RSS 15.43

           REAcq(1,2,1) @ 350/02:06:00 was successful

11103 - GSAcq(2,1,2) results in finelock backup (2,0,2) using FGS-2

           Upon acquisition of signal at 350/20:35:20, the GSAcq(2,1,2) scheduled

           at 350/19:33:11 - 19:41:16 had resulted to finelock backup (2,0,2) using

           FGS-2,due to stop flag (QF1STOPF) indication on FGS-1. Pre-acquisition

           OBAD1 had attitude error correction (RSS) value of 1824.19 arcseconds.

           OBAD2 attitude error correction (RSS) not available pending future ETR

           Dump. Post-acq OBAD/MAP had (RSS) value of 19.65 arcseconds. Subsequent

           REacq(2,1,2) scheduled at 350/21:07:49 using same guide star pair

           resulted to finelock backup (2,0,2) using FGS-2 due to stop flag on

           FGS-1.

11104 - GSAcq(1,2,2) resulted in Fine Lock Back-up (1,0,1)

           GSAcq (1,2,2) scheduled from 09:36:13 - 09:43:26 resulted in Fine Lock

           Back-up (1,0,1) using FGS 1. This was due to QF2STOPF flag on FGS 2 and

           QSTOP flag. At 09:39:50 received 486 ESB message 1808 "TxG FHST Sanity

           Check Failed". Pre-acquisition OBAD1 had attitude error correction (RSS)

           value of 2691.62 arcseconds. Pre-acquisition OBAD2 had attitude error

           correction (RSS) value of 5.39 arcseconds. Post acquisition OBAD MAP was

           not scheduled.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                       SCHEDULED      SUCCESSFUL  

FGS GSacq               27                  25                     

FGS REacq               17                  17                               

OBAD with Maneuver 88                  88                    

SIGNIFICANT EVENTS:

FSW 3.1 Release B was successfully installed into HST486 EEPROM at

348/13:00:34. The load completed successfully and the valid block

counter was verified. The post installation EEPROM dump was completed at

348/15:16:59, and the Compare Best Estimate of the dump file against the

EEPROM load showed no miscompares and no missing blocks. FSW also

verified the contents of the memory dump.