Notice: For the foreseeable future, the daily reports may contain

apparent discrepancies between some proposal descriptions and the listed

instrument usage. This is due to the conversion of previously approved

ACS WFC or HRC observations into WFPC2, or NICMOS observations

subsequent to the loss of ACS CCD science capability in late January.

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT       # 4351

PERIOD COVERED: UT April 27,28,29, 2007 (DOY 117,118,119)

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

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

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

passages leave different imprints on the NICMOS detectors.

WFPC2 11091

Hubble Heritage Observations of Arp 148

The Hubble Heritage team will use a single pointing of WFPC2 to obtain

F450W, F555W, F656N, and F814W images of Arp 148 as part of a public

release image.

WFPC2 11085

Europa in Eclipse: Tenuous Atmosphere, Electromagnetic Activity and

Surface Luminescence HST Proposal 11085

We propose to image Europa during its orbital eclipse by Jupiter. This

will form the basis of an investigation into the nature of the tenuous

atmosphere, electromagnetic environment and surface material of Europa.

We will compare the FUV oxygen line at 1356A to the optical line at

6300A and seek optical auroral hydrogen emission in Halpha. With broad

continuum filters, we will search for optical emissions from other

atmospheric constituents and for fluorescence of the surface material,

arising from the very high level of incident energetic particle

radiation. The high spatial resolution of ACS will allow us to fully

resolve scales of interest and allow us to distinguish easily the

different terrains on Europa's surface. In particular we wish to compare

luminesence in regions dominated by ice to those of potentially organic

red material.

WFPC2 11083

The Structure, Formation and Evolution of Galactic Cores and Nuclei

A surprising result has emerged from the ACS Virgo Cluster Survey

{ACSVCS}, a program to obtain ACS/WFC gz imaging for a large, unbiased

sample of 100 early-type galaxies in the Virgo Cluster. On subarcsecond

scales {i.e., <0.1"-1"}, the HST brightness profiles vary systematically

from the brightest giants {which have nearly constant surface brightness

cores} to the faintest dwarfs {which have compact stellar nuclei}.

Remarkably, the fraction of galaxy mass contributed by the nuclei in the

faint galaxies is identical to that contributed by supermassive black

holes in the bright galaxies {0.2%}. These findings strongly suggest

that a single mechanism is responsible for both types of Central Massive

Object: most likely internally or externally modulated gas inflows that

feed central black holes or lead to the formation of "nuclear star

clusters". Understanding the history of gas accretion, star formation

and chemical enrichment on subarcsecond scales has thus emerged as the

single most pressing question in the study of nearby galactic nuclei,

either active or quiescent. We propose an ambitious HST program {199

orbits} that constitutes the next, obvious step forward:

high-resolution, ultraviolet {WFPC2/F255W} and infrared {NIC1/F160W}

imaging for the complete ACSVCS sample. By capitalizing on HST's unique

ability to provide high-resolution images with a sharp and stable PSF at

UV and IR wavelengths, we will leverage the existing optical HST data to

obtain the most complete picture currently possible for the history of

star formation and chemical enrichment on these small scales. Equally

important, this program will lead to a significant improvement in the

measured structural parameters and density distributions for the stellar

nuclei and the underlying galaxies, and provide a sensitive measure of

"frosting" by young stars in the galaxy cores. By virtue of its superb

image quality and stable PSF, NICMOS is the sole instrument capable of

the IR observations proposed here. In the case of the WFPC2

observations, high-resolution UV imaging {< 0.1"} is a capability unique

to HST, yet one that could be lost at any any time.

NIC1/NIC3 10924

Constraints on the Assembly and Dynamical Masses of z~2 Galaxies

We propose deep NICMOS/NIC2 F160W imaging of seven star-forming galaxies

at z~2. These galaxies comprise an entirely unique sample, with not only

redshifts measured from optical and near-IR spectra, but also

SINFONI/VLT near-IR integral field spectroscopic measurements providing

kinematic maps of H-alpha emission out to radii of >=10 kpc. We aim to

determine the dynamical masses and evolutionary states of these systems,

as part of the larger goal of understanding how mass is assembled in

distant galaxies. In order to interpret our novel H-alpha integral field

maps in terms of mass, we require detailed knowledge of the structural

parameters of our target objects at rest-frame optical wavelengths and

on ~1 kpc scales. We want to establish if the mass is distributed in a

disk, bulge, or merging sub-units, and if we can detect tidal features

associated with a merger. F160W imaging with NICMOS/NIC2 provides the

perfect combination of sensitivity and resolution to address these

questions, and arrive at the fundamental quantity: the dynamical mass.

WFPC2 10890

Morphologies of the Most Extreme High-Redshift Mid-IR-Luminous Galaxies

The formative phase of the most massive galaxies may be extremely

luminous, characterized by intense star- and AGN-formation. Till now,

few such galaxies have been unambiguously identified at high redshift,

restricting us to the study of low-redshift ultraluminous infrared

galaxies as possible analogs. We have recently discovered a sample of

objects which may indeed represent this early phase in galaxy formation,

and are undertaking an extensive multiwavelength study of this

population. These objects are bright at mid-IR wavelengths

{F[24um]>0.8mJy}, but deep ground based imaging suggests extremely faint

{and in some cases extended} optical counterparts {R~24-27}. Deep K-band

images show barely resolved galaxies. Mid-infrared spectroscopy with

Spitzer/IRS reveals that they have redshifts z ~ 2-2.5, suggesting

bolometric luminosities ~10^{13-14}Lsun! We propose to obtain deep ACS

F814W and NIC2 F160W images of these sources and their environs in order

to determine kpc-scale morphologies and surface photometry for these

galaxies. The proposed observations will help us determine whether these

extreme objects are merging systems, massive obscured starbursts {with

obscuration on kpc scales!} or very reddened {locally obscured} AGN

hosted by intrinsically low-luminosity galaxies.

NIC3 10855

The Near-IR Spectra and Thermal Emission of Hot Jupiters

We propose to observe the brightest transiting exoplanet systems, HD

209458b and HD 189733b, during both primary eclipse {transit} and

secondary eclipse {when the planet is behind the star}. A successful

measurement would result in the spectral characterization of both

dayside and nightside thermal emission. This, in turn, would result in

several important determinations, including {1} the temperature of the

dayside, {2} the temperature of the nightside, {3} the probable

detection of water, {4} strong constraints on the presence or absence of

clouds, and {5} constraints on models of atmospheric transport between

the day and night sides. Our selected wavelength region of 1.4 to 2.4

microns includes the two most prominent predicted features {water} in

models for hot Jupiter emission. For these observations, we propose to

use the NICMOS 3 grism and selected narrow band filters in a carefully

designed, differential observation intended to achieve a dynamic range

of 10,000:1. Our proposed observations are uniquely enabled by HST,

which alone has the combination of stability, sensitivity, wavelength

coverage, and dynamic range to make these high- impact observations

possible.

WFPC2 10786

Rotational state and composition of Pluto's outer satellites

We propose an intricate set of observations aimed at discovering the

rotational state of the newly discovered satellites of Pluto, S/2005 P1

and S/2005 P2. These observations will indicate if the satellites are in

synchronous rotation or not. If they are not, then the observations will

determine the rotational period or provide tight constraints on the

amplitude. The other primary goal is to extend the wavelength coverage

of the colors of the surface and allow us to constrain the surface

compositions of both objects. From these data we will also be able to

significantly improve the orbits of P1 and P2, improve the measurement

of the bulk density of Charon, and search for albedo changes on the

surface of Pluto.

WFPC2 10474

Shooting Stars: Looking for Direct Evidence of Massive Central Black

Holes in Globular Clusters

We propose to make observations that directly test the proposition that

globular clusters contain massive black holes. Our targets are the bulge

globular clusters NGC 6388 and NGC 6441. These are probably among the

most massive in the galaxy, but are understudied compared to more

familiar objects such as M15. Our analysis suggests that these two

clusters are the most likely to show unambiguous evidence for a central

massive black hole if such things exist in globular clusters. The

observations proposed will give us the first thorough kinematic and

photometric studies of these two clusters. The combination of the two

epochs will give us proper motions good to of order 6 km/s. In addition,

they will provide us with the first good, deep, color-magnitude diagrams

for these clusters. These diagrams will be used to investigate the make

up of the stellar population in the clusters, to more firmly establish

their distances, ages, and metallicities, and to search for a binary

sequence.

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               17                   17                  

FGS REacq               21                   21                

OBAD with Maneuver 60                   60              

SIGNIFICANT EVENTS:

Flash Report: HST Clock Rollover

The HST vehicle clock rollover occurred as expected

on April 29, 2007 (DOY 119) at 18:06:30.769 GMT. Pre- and post-rollover

operations were conducted nominally in accordance with the planned

timeline and procedure. The first scheduled guide star acquisition after

rollover occurred successfully at 119/20:16:33.