HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science



DAILY REPORT #4674



PERIOD COVERED: 5am August 13 - 5am August 14, 2008 (DOY 226/0900z-227/0900z)



OBSERVATIONS SCHEDULED



NIC1/NIC2/NIC3 11330



NICMOS Cycle 16 Extended Dark



This takes a series of Darks in parallel to other instruments.



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.



NIC2 11197



Sweeping Away the Dust: Reliable Dark Energy with an Infrared Hubble

Diagram



We propose building a high-z Hubble Diagram using type Ia supernovae

observed in the infrared rest-frame J-band. The infrared has a number of

exceptional properties. The effect of dust extinction is minimal,

reducing a major systematic that may be biasing dark energy

measurements. Also, recent work indicates that type Ia supernovae are

true standard candles in the infrared meaning that our Hubble diagram

will be resistant to possible evolution in the Phillip's relation over

cosmic time. High signal-to-noise measurements of 16 type Ia events at

z~0.4 will be compared with an independent optical Hubble diagram from

the ESSENCE project to test for a shift in the derived dark energy

equation of state due to a systematic bias. In Cycle 15 we obtained

NICMOS photometry of 8 ESSENCE supernovae and are awaiting template

observations to place them on the IR Hubble diagram. Here we request

another 8 supernovae be studied in the final season of the ESSENCE

search. Because of the bright sky background, H-band photometry of z~0.4

supernovae is not feasible from the ground. Only the superb image

quality and dark infrared sky seen by HST makes this test possible. This

experiment may also lead to a better, more reliable way of mapping the

expansion history of the universe with the Joint Dark Energy Mission.



NIC2 11799



NICMOS Non-linearity Calibration for Faint Objects



NICMOS has played a key role in probing the deep near infrared regime

for a decade. It has been the only instrument available to observe

objects in the near infrared that are not visible from the ground. In

particular, it has played a major role in the SN Ia observations at

redshifts z>1. However, the calibration of NICMOS has turned out to be

difficult due to the apparent non-linearity of the detectors. The NICMOS

calibration team has described the non-linearity as a power law based on

data in the range of ~50-5000 ADU/s. The correction relies on an

extrapolation of two orders of magnitude in flux at count rates close to

the sky level (0.1 ADU/s) where space observations are particularly

prized - and where SN Ia observations are made. Precise measurements of

faint objects require us to reduce the uncertainties from this

extrapolation. Here we propose to derive the absolute calibration in the

sky limited regime and to characterize the non-linearity over the entire

dynamic range for the camera/filter combination: NIC2/F110W.



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.



WEPC2 11196



An Ultraviolet Survey 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 starbursts and creating/fueling central AGN. We

propose far {ACS/SBC/F140LP} and near {WFPC2/PC/F218W} UV imaging of a

sample of 27 galaxies drawn from the complete IRAS Revised Bright Galaxy

Sample {RBGS} LIRGs sample and known, from our Cycle 14 B and I-band ACS

imaging observations, to have significant numbers of bright {23 < B < 21

mag} star clusters in the central 30 arcsec. The HST UV data will be

combined with previously obtained HST, Spitzer, and GALEX images to {i}

calculate the ages of the clusters as function of merger stage, {ii}

measure the amount of UV light in massive star clusters relative to

diffuse regions of star formation, {iii} assess the feasibility of using

the UV slope to predict the far-IR luminosity {and thus the star

formation rate} both among and within IR-luminous galaxies, and {iv}

provide a much needed catalog of rest- frame UV morphologies for

comparison with rest-frame UV images of high-z LIRGs and Lyman Break

Galaxies. These observations will achieve the resolution required to

perform both detailed photometry of compact structures and spatial

correlations between UV and redder wavelengths for a physical

interpretation our IRX-Beta results. The HST UV data, combined with the

HST ACS, Spitzer, Chandra, and GALEX observations of this sample, will

result in the most comprehensive study of luminous starburst galaxies to

date.



WFPC2 11122



Expanding PNe: Distances and Hydro Models



We propose to obtain repeat narrowband images of a sample of eighteen

planetary nebulae {PNe} which have HST/WFPC2 archival data spanning time

baselines of a decade. All of these targets have previous high

signal-to-noise WFPC2/PC observations and are sufficiently nearby to

have readily detectable expansion signatures after a few years. Our main

scientific objectives are {a} to determine precise distances to these

PNe based on their angular expansions, {b} to test detailed and highly

successful hydrodynamic models that predict nebular morphologies and

expansions for subsamples of round/elliptical and axisymmetric PNe, and

{c} to monitor the proper motions of nebular microstructures in an

effort to learn more about their physical nature and formation

mechanisms. The proposed observations will result in high-precision

distances to a healthy subsample of PNe, and from this their expansion

ages, luminosities, CSPN properties, and masses of their ionized cores.

With good distances and our hydro models, we will be able to determine

fundamental parameters {such as nebular and central star masses,

luminosity, age}. The same images allow us to monitor the changing

overall ionization state and to search for the surprisingly

non-homologous growth patterns to bright elliptical PNe of the same sort

seen by Balick & Hajian {2004} in NGC 6543. Non-uniform growth is a sure

sign of active pressure imbalances within the nebula that require

careful hydro models to understand.



WFPC2 11177



The Nature of z=3 Lyman-Alpha Emitters



The advent of large mosaic CCD cameras on 4 -- 8 m class telescopes has

recently led to a revolution in our ability to detect primordial

galaxies. Today, large numbers of strong Ly-alpha emitters (LAEs) are

being discovered between 2.4 < z < 6. These are important objects: not

only do they sample a part of the galaxy luminosity function that is

inaccessible to the Lyman-break technique, but they also tend to be

younger and less chemically evolved. In fact, the LAEs now being found

are currently our best candidates for galaxies in the act of formation.

To investigate the properties of this class of objects, we have

conducted an extremely deep narrow-band (5000 Angstrom; FWHM = 50

Angstrom) and broad-band (UBVRIzJK) survey of the Extended Chandra Deep

Field South, and have identified a homogeneous sample of strong Ly-

alpha emitters at z = 3.11. Twenty-seven of these objects are located

within the region surveyed by Great Observatories Origins Deep Survey

(GOODS) and have detailed morphological information available from the

rest-frame ultraviolet. We propose 0.2" resolution narrow-band imaging

of 11 of our LAEs using the F502N filter of WFPC2. By comparing the

Ly-alpha and rest-frame UV continuum morphologies of these galaxies, we

will be able to look for the presence of outflows, constrain their dust

content, and test whether these objects are truly primordial galaxies.



WFPC2 11227



The Orbital Period for an Ultraluminous X-ray Source in NGC1313



The ultraluminous X-ray sources {ULXs} are extragalactic point sources

with luminosities that exceed the Eddington luminosity for conventional

stellar-mass black holes by factors of 10 - 100. It has been hotly

debated whether the ULXs are just common stellar-mass black hole sources

with beamed emission or whether they are sub-Eddington sources that are

powered by the long-sought intermediate mass black holes {IMBH}. To

firmly decide this question, one must obtain dynamical mass measurements

through photometric and spectroscopic monitoring of the secondaries of

these system. The crucial first step is to establish the orbital period

of a ULX, and arguably the best way to achieve this goal is by

monitoring its ellipsoidal light curve. The extreme ULX NGC1313 X-2

provides an outstanding target for an orbital period determination

because its relatively bright optical counterpart {V = 23.5} showed a

15% variation between two HST observations separated by three months.

This level of variability is consistent with that expected for a tidally

distorted secondary star. Here we propose a set of 20 imaging

observations with HST/WFPC2 to define the orbital period. This would be

the first photometric measurement of the orbital period of a ULX binary.

Subsequently, we will propose to obtain spectroscopic observations to

obtain its radial velocity amplitude and thereby a dynamical estimate of

its mass.



WFPC2 11336



X-ray and UV Photo-ionization and Photo-excitation of Pre-main-sequence Star

Transitional Disks



Transitional disks are one of the most crucial and important stages of

the evolution of pre-main-sequence stars and protoplanetary systems.

These disks have transformed most of the dust and gas in their inner

regions into planetesimals and show clear inner ``holes'' that almost

certainly harbor infant planetary systems. We propose to observe 3 young

stars with transitional disks (T Cha, GM Aur, LkHa 330) using ACIS-S to

measure their X-ray radiation field and coronal emission properties and

HST ACS- SBC to image the fluorescently excited molecular hydrogen in

these systems to determine if the gas distribution follows the behavior

seen in the dust distribution. [Only observations of GM Aur were

approved. ]Our broader goal is to model the X-ray/UV photoionization and

photoexcitation of the disks and study their photochemistry.



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 08 08

FGS REacq 07 07

OBAD with Maneuver 30 30



SIGNIFICANT EVENTS: (None)