Daily 3845

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3845

PERIOD COVERED: DOYs 112-114

OBSERVATIONS SCHEDULED


ACS/HRC/WFPC2 9827

UV extinction by dust in unexplored LMC environments

The ensemble of results from studies of the UV extinction in the Milky
Way, Magellanic Clouds {MC}, M31 and M33, indicates a complex
dependence of the dust properties with environment, where starburst
activity and metallicity are relevant factors. Work in the LMC to
date, based on IUE data, has several drawbacks: a} only supergiants
could be used, b} they all have moderate extinction, c} the IUE S/N is
limited, d} the large IUE slit may include light from other sources,
such as scattered light from dust or faint companion stars, e} studies
are confined to few {extreme} environments. We propose to obtain UV
extinction curves more accurate than previous ones, sampling four
environments in the LMC with different levels of star formation
activity, including the general field, hitherto unexplored. The
results will characterize the properties of dust in different
conditions, at the LMC metallicity, which is useful to interpret
integrated properties of distant galaxies, as well as GALEX upcoming
UV surveys. A complementary study is planned with FUSE in the far-UV
range. The combined results will provide insight on the properties of
small grains.

ACS/WFC 9811

Establishing the Metallicity Distribution in Normal Giant Ellipticals

NGC 3377 and 3379, the Leo Group ellipticals at d=11 Mpc, are the
nearest E galaxies commonly regarded to be structurally" normal", and
as such, they are keystone objects for understanding the evolution and
early star formation history of large ellipticals. The ACS/WFC camera
now gives us the ability to obtain the metallicity distribution
function {MDF} of their stellar population by direct resolution and
photometry of their halo stars. To do this, we will follow the same
highly successful techniques we have previously used for NGC 5128 with
WFPC2 {V, I} imaging: the {V-I} colors of the brightest red-giant
stars are highly sensitive to metallicity, and their locations in the
color-magnitude diagram can be used for direct construction of the
MDF. This will be a major step forward to understanding the formation
history of these cosmologically dominant galaxies.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

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.

NIC1/NIC2/NIC3 10454

Extreme count rates linearity test for NICMOS

This NICMOS calibration proposal tests the linearity of the detectors
at count rates falling at the low and high extremes of what is
feasible. This program is a response to the discovery that grism
observations obtained with NIC3 show a systematic offset from spectra
taken with STIS and ACS in the 0.8-1.0 micron overlap region. The
observations are consistent with a NIC3 sensitivity that depends on
incident flux, i.e. count rate. By observing one bright star
{BD+17D4708, the Sloan Digital Sky Survey absolute standard} and two
faint stars {SNAP-2, a solar analog star; WD1657+343, a white dwarf}
in a number of filters we will check whether this is an intrinsic
feature of the all NICMOS detectors, something intrinsic to NIC3, or a
result of a not understood effect of the grism observations. We will
furthermore be able to test whether the effect has a wavelength
dependence. The data will be reduced in exactly the same fashion as
has been done before for the photometric calibration program, so a
direct comparison with previous data can be made. In addition, we will
obtain extra spectroscopic data on WD1657+343, the faintest and best
modeled white dwarf of the stars on which the original discovery of
the non-linearity was made. This will reduce the errors in this
spectrum from 5% to 2% and will allow a better estimate of the effect.
In order to ease scheduling, there are no time constraints specified
in the proposal. However, because of the potentially important
implications of this effect, it is very important that these orbits be
scheduled as soon as possible. They could be critical for the proper
calibration of NICMOS The targets have visibility 1} BD+17D4708: 16
Apr - 17 Jan 2} SNAP-2: 3 Feb-1 Mar 3} WD1657+343: 3 Feb-26 Feb

ACS/HRC/WFC 10438

The Late Formation of Satellite Galaxies

Tiny isolated HII regions have been discovered up to 30 kpc from the
closest galaxy in the NOAO Survey for Ionization in Neutral Gas
Galaxies {SINGG}. These halo HII regions can be ionized by only a few
OB stars and seem to be most commonly found in interacting systems.
They may represent the beginning of the formation of satellite
galaxies at low redshift and/or are the source of the numerous
intracluster planetary nebula. The halo HII regions are a unique mode
of star formation in a low density and low metallicity environment and
high resolution HST images are required to identify their underlying
stellar populations. Determining the stellar populations of these HII
regions will establish whether in-situ star formation is a significant
contributor to the stellar content and enrichment of galactic halos
and intergalactic space. In particular, ACS/HRC observations are
required for their resolution, UV sensitivity, and wide wavelength
coverage, allowing young and intermediate age populations to be
identified. Parallel ACS/WFC observations will explore the possibility
of a further stellar population in the interactive debris. The results
of this project have implications on the formation of satellite
galaxies, the origin of Galactic halo B stars, IGM ionization and
enrichment, and star formation principles.

ACS/HRC/WFC 10436

Black Hole Growth and the Black Hole Mass -- Bulge Relations for AGNs

Recent work has shown that the mass of a black hole is tightly
correlated with the bulge mass of its host galaxy. This relation needs
to be understood in the context of black hole growth in its active
phase. Highly accreting AGNs, like narrow line Seyfert 1 galaxies
{NLS1s}, are found to lie below the black hole mass -- bulge velocity
dispersion correlation of normal galaxies and broad line AGNs. This
result was obtained using FWHM{[OIII]} as a surrogate for the bulge
velocity dispersion. To test this result we propose to obtain high
resolution images of 10 NLS1s that do not lie on the black hole
mass--sigma relation and measure accurate bulge parameters {luminosity
and effective radius}. We will obtain an alternate handle on the bulge
velocity dispersion through the fundamental plane relations and also
find the locus of these NLS1s on the black hole mass--bulge luminosity
plane. Testing this result is crucial to understanding the role of
accretion on black hole growth, the observed correlations of the black
hole mass with the bulge, and the formation and evolution of galaxies.

ACS/HRC 10434

Particle accelerators in space: resolving them for the first time

The detection of optical counterparts of hot spots in radio galaxies
has been a challenge in astrophysics since the 1960s. Being located at
several 100 kpc away from the AGN, they represent the most striking
sites of interaction between the AGN ejecta and the ambient
inter-galactic medium. Particle acceleration is thought to drive their
emission and therefore, due to their remote locations, hot spots are
the best laboratories to study the physics of that mechanism in
detail. Using carefully directed selection criteria and the VLT we
have discovered hot spots in the optical at an unprecedented detection
rate, all of them disclosing very intriguing structure. This structure
pinpoints the regions where electrons are accelerated to highly
relativistic energies -- the particle accelerators. With HST we aim at
resolving these accelerators for the very first time. This will enable
us to establish the nature and origin of these relativistic particles
in the hot spots of radio galaxies. The results of these studies not
only represent a key for understanding the evolution of radio sources
but also provide important input to plasma acceleration problems in
general.

ACS/WFC 10412

The host galaxies of dust-reddened quasars

We have used the 2MASS near-infrared and FIRST radio surveys, together
with the Palomar Observatory Sky Survey plates to select a sample of
dust-reddened, radio- intermediate quasars. We wish to use ACS to
study the host galaxies of these quasars. The dust reddening of the
quasars makes it possible to study the hosts at rest-frame optical-UV
wavelengths much more easily than the hosts of normal quasars of
similar bolometric luminosity. Our study will compare the hosts of our
dust-reddened quasars to those of normal quasars from the HST archive
to test the hypothesis that dust-reddened quasars are young objects,
whose hosts still show morphological evidence of recent merger events
which triggered the quasar.

ACS/HRC 10391

Wavelength and Flux Calibration of the ACS prisms

The wavelength calibration of the SBC {PR110L and PR130L} and HRC
{PR200L} prisms will be established by observing a planetary nebula in
the LMC and QSOs at carefully selected redshifts. Flux calibrations
will be derived for each prism by observing white dwarf standards.

ACS/HRC/WFC 10389

ACS CCDs daily monitor - Cycle 13 - Part 2

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This programme will be
for the entire lifetime of ACS.

ACS/HRC 10377

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L- flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronagraphic
monitoring is required to assess the changing position of the spots.

ACS/WFC 10369

ACS internal CTE monitor

The charge transfer efficiency {CTE} of the ACS CCD detectors will
decline as damage due to on-orbit radiation exposure accumulates. This
degradation will be closely monitored at regular intervals, because it
is likely to determine the useful lifetime of the CCDs. All the data
for this program is acquired using internal targets {lamps} only, so
all of the exposures should be taken during Earth occultation time
{but not during SAA passages}. This program emulates the ACS
pre-flight ground calibration and post-launch SMOV testing {program
8948}, so that results from each epoch can be directly compared.
Extended Pixel Edge Response {EPER} and First Pixel Response {FPR}
data will be obtained over a range of signal levels for both the Wide
Field Channel {WFC}, and the High Resolution Channel {HRC}.

ACS/HRC 10330

Coronagraphic search for disks around nearby stars

We will use the coronagraphic and imaging modes of the High Resolution
camera to study of the role of circumstellar disks in planetary system
formation over timescales of ~1-1000 Myr. Our targets comprise pre
Main-Sequence {MS} and MS stars, selected by infrared excess, and
targets selected from SIRTF surveys. Some targets, like Beta Pictoris
have debris disks that have been detected at optical or near-IR
wavelengths, while others have disks inferred from mid-IR or ISO
observations. We will obtain multicolor images of each target's
circumstellar environment for the purpose of {1} detecting and
characterizing disk morphologies over all scales {including warps and
regions of enhanced or depleted density}, and {2} seeking evidence of
embedded planets. Direct and occulted images will be recorded for
studying the disks within 2 arcseconds of these targets; the
coronagraph will be used to image the outer regions of the disks.
Together with existing infrared observations, we will provide
constraints on the sizes, distribution, and composition of dust
grains. Unconfirmed disks will first be imaged in F606W, and if they
exist we may later observe them in F435W and F814W.

ACS/HRC/WFC 10263

SAINTS - Supernova 1987A Intensive Survey

SAINTS is a program to observe SN 1987A, the brightest supernova in
383 years, as it transforms into supernova remnant {SNR} 1987A, the
youngest supernova remnant. HST is the unique and perfect match in
scale and in field for spatially-resolved observations of SN 1987A.
Rapid changes are taking place in a violent encounter between the
fastest-moving debris and the circumstellar ring. This one-time-only
event, leading to suddenly appearing hotspots and new emission that
can reveal previously hidden gas, is powered by shocks that can be
studied simultaneously with HST and with Chandra to great advantage.
Both the optical and X-ray flux from the ring are rising rapidly so
prompt observations are needed in Cycle 13. Our previous observations
reveal a remarkable reverse shock moving upstream through the
expanding debris. The reverse shock provides a powerful tool for
dissecting the radial structure of the vanished star. The debris from
the explosion itself, still excited by radioactivity, is now well
resolved by ACS and seen to be aspherical, providing direct clues to
the mechanism of the explosion. Many questions about SN 1987A remain
unanswered. SAINTS is a comprehensive attempt to use HST to establish
the facts of SN 1987A, help to answer interesting questions, and to
observe the birth of SNR 1987A.

ACS/HRC 10259

Planetary nebulae in the SMC: a study of stellar evolution and
populations in an extremely low-metallicity environment

The final phase of the evolution of low- and intermediate-mass stars,
the planetary nebula {PN} ejection, is thought to largely contribute
to the carbon and nitrogen enrichment in galaxies, in particular in
old stellar populations. Stellar generations forming from a carbon-
and nitrogen-enriched medium are a necessary condition for planetary
and life formation. It is essential to understand how stars go through
the process of shedding their chemically-enriched shells, and to test
the predictions of stellar evolution theory on the relationship
between stellar mass and elemental enrichment. Magellanic Cloud PNs
are ideal probes for this study. Their abundances can be directly
related to the mass of the central stars and to that of the stellar
progenitor, without the great {distance and reddening} uncertainties
that affect Galactic PNs. The UV lines are essential for calculating
the abundances of the element related to stellar evolution {C, N, O}
and to progenitor populations {e.g., Ne}. We propose to acquire UV
spectroscopy of the SMC PNs whose morphology and central star
properties has been previously determined by us with HST. We will
derive the {C, N, O} abundance-to-mass relation, and determine the
extent to which the mass of the progenitors of asymmetric PNs exceed
that of symmetric PNs. We will also test the PN luminosity function,
and probe cosmic recycling, in a very low-metallicity environment.

ACS/HRC 10198

Probing the Dynamics of the Galactic Bar through the Kinematics of
Microlensed Stars

The observed optical depths to microlensing of stars in the Galactic
bulge are difficult to reconcile with our present understanding of
Galactic dynamics. The main source of uncertainty in those comparisons
is now shifting from microlensing measurements to the dynamical models
of the Galactic bar. We propose to constrain the Galactic bar models
with proper motion observations of Bulge stars that underwent
microlensing by determining both the kinematic identity of the
microlensed sources and the importance of streaming motions. The
lensed stars are typically farther than randomly selected stars.
Therefore, our proper motion determinations for 36 targeted MACHO
events will provide valuable constraints on the dynamics of bulge
stars as a function of distance. The first epoch data for our proposed
events is already available in the HST archive so the project can be
completed within a single HST cycle. The exceptional spatial
resolution of HST is essential for completion of the project.
Constraints on the total mass in the bulge will ultimately lead to the
determination of the amount of dark matter in inner Galaxy.

ACS/WFC 10174

Dark-matter halos and evolution of high-z early-type galaxies

Gravitational lensing and stellar dynamics provide two complementary
methods to determine the mass distribution and evolution of luminous
and dark-matter in early-type {E/S0} galaxies. The combined study of
stellar dynamics and gravitational lensing allows one to break
degeneracies inherent to each method separately, providing a clean
probe of the internal structure of massive galaxies. Since most lens
galaxies are at redshifts z=0.1-1.0, they also provide the required
look-back time to study their structural and stellar-population
evolution. We recently analyzed 5 E/S0 lens galaxies between z=0.5 and
1.0, combining exquisite Hubble Space Telescope imaging data with
kinematic data from ground-based Keck spectroscopy, placing the first
precise constraints on the dark- matter mass fraction and its inner
slope beyond the local Universe. To expand the sample to ~30 systems
-- required to study potential trends and evolution in the E/S0 mass
profiles -- we propose to target the 49 E/S0 lens-galaxy candidates
discovered by Bolton et al. {2004} from the Sloan Digital Sky Survey
{SDSS}. With the average lens rate being 40% and some systems having a
lensing probability close to unity, we expect to discover ~20 strong
gravitational lenses from the sample. This will triple the current
sample of 9 E/S0 systems, with data in hand. With the sample of 30
systems, we will be able to determine the average slope of the
dark-matter and total mass profile of E/S0 galaxies to 10% and 4%
accuracy, respectively. If present, we can simultaneously detect 10%
evolution in the total mass slope with 95% confidence. This will
provide unprecedented constraints on E/S0 galaxies beyond the local
Universe and allow a stringent test of their formation scenarios and
the standard cosmological model.

ACS/WFC/WFPC2 10129

Resolving Globular Clusters in NGC 1399

We intend to use the ACS/WFC to measure structural parameters {half
light radius, King core radius and concentration parameter} of
individual globular clusters {GCs} in NGC 1399. Very little is known
about structural parameters of globular clusters as a function of
radius outside the Local Group. The proposed observations, arranged in
a 3x3 ACS mosaic, will allow us to perform the first detailed
wide-field study of structural parameters of globular clusters in a
giant elliptical galaxy. In particular we will: 1} study the
size-galactocentric distance relation of globular clusters out to ~55
kpc {~1.6 eff. radius of the GCS} and determine whether the observed
differences in sizes between metal-rich and metal-poor globular
cluster in early-type galaxies are primordial and thereby reflect
fundamental differences in formation, or are due to projection
effects; 2} match the GC position observed with HST/ACS with X-ray
binaries identified over the full Chandra field, and use the above
sizes to constrain physical models for X-ray binary formation in GCs.
3} The wealth of ground-based data available for this system
{photometry+spectroscopy}, will allow us to correlate the structural
properties with other GC properties, such as their chemical
composition, luminosity, etc.

ACS/WFC/WFPC2 10092

The COSMOS 2-Degree ACS Survey

We will undertake a 2 square degree imaging survey {Cosmic Evolution
Survey -- COSMOS} with ACS in the I {F814W} band of the VIMOS
equatorial field. This wide field survey is essential to understand
the interplay between Large Scale Structure {LSS} evolution and the
formation of galaxies, dark matter and AGNs and is the one region of
parameter space completely unexplored at present by HST. The
equatorial field was selected for its accessibility to all
ground-based telescopes and low IR background and because it will
eventually contain ~100, 000 galaxy spectra from the VLT-VIMOS
instrument. The imaging will detect over 2 million objects with I 27
mag {AB, 10 sigma}, over 35, 000 Lyman Break Galaxies {LBGs} and
extremely red galaxies out to z ~ 5. COSMOS is the only HST project
specifically designed to probe the formation and evolution of
structures ranging from galaxies up to Coma-size clusters in the epoch
of peak galaxy, AGN, star and cluster formation {z ~0.5 to 3}. The
size of the largest structures necessitate the 2 degree field. Our
team is committed to the assembly of several public ancillary datasets
including the optical spectra, deep XMM and VLA imaging, ground-based
optical/IR imaging, UV imaging from GALEX and IR data from SIRTF.
Combining the full-spectrum multiwavelength imaging and spectroscopic
coverage with ACS sub-kpc resolution, COSMOS will be Hubble's ultimate
legacy for understanding the evolution of both the visible and dark
universe.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTAR 9787: GS Acq (1,2,1) Failure to RGA Control 5/113/11:19:28z.
GSAcq (1,2,1) scheduled at 113/11:15:40 failed to enter Fine Lock,
with Search Radius Limit Exceeded at 113/11:19:28. All subsequent
attempts failed. Possible Observations affected: ACS 203-206, NIC
39-43 REAcq's scheduled at 113/12:51:30, 113/14:27:27, 113/16:03:23
all failed to RGA control due to Search Radius Limit Exceeded. Under
investigation.


COMPLETED OPS REQs:
17425-0 Genslew for Proposal 10263 Slot#3 @112/1705z
17426-0 R/T Map @113/1311z
17427-0 R/T Map @113/1612z


OPS NOTES EXECUTED:
1331-0 Change JERRCNT Limit @111/2130z

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS
Gsacq 24 23 @113/1119z
(HSTAR#9787)
FGS
Reacq 22 19
@113/1251z,1427z,1603z (HSTAR#9787)
FHST Update 40 40
LOSS of LOCK


SIGNIFICANT EVENTS:

The Hubble Space Telescope Team today celebrates the 15th anniversary
of the launch of the Hubble Space Telescope (April 24, 1990).