Daily Report #4453

Notice: Due to the conversion of some ACS WFC or HRC observations into
WFPC2, or NICMOS observations after the loss of ACS CCD science
capability in January, there may be an occasional discrepancy between
a proposal's listed (and correct) instrument usage and the abstract
that follows it.


HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT****** # 4453

PERIOD COVERED: UT September 21,22,23, 2007 (DOY 264,265,266)

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 DARKs. 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.

NIC3 11335

NICMOS Defocus parameter test

This proposal tests the new NICMOS non-nominal focus positions, which
are implemented in the front-end systems and are specified in the
Phase II using the CAMERA-FOCUS=DEFOCUS Optional Parameter. The
targets from Proposals 9832 and 11063 are used in this Proposal. The
GO Proposal 9832 is an example of how GOs may use the new non-nominal
focus implementation for detector 3. Proposal 11063 is the NICMOS
focus monitor, which will be used to verify the non-nominal focus for
all 3 detectors.

WFPC2 11224

Unraveling Mira AB Accretion Mysteries

Wind accretion is one of the most common yet poorly understood
phenomena in astrophysics. A key step toward advancing our
understanding of physical processes and accretion geometries in wind
accreting systems is direct imaging of the individual components and
mass flows. The nearby symbiotic binary Mira AB, composed of an AGB
donor star and an accreting compact companion, is a unique target
since it can be easily spatially resolved with the HST, and thus
serves as a perfect test laboratory for accretion studies in wind
interacting systems. We propose to carry out WFPC2 observations of
Mira AB following the HST and Chandra detections of an unprecedented
outburst from the cool giant, and the discovery of an accretion stream
showing for the first time evidence for a direct mass transfer between
the components in a wind accreting system. High-angular- resolution
multiwavelength imaging at UV /optical wavelengths will allow us to
determine the properties of the ejected material as it flows
throughout the binary and interacts with the Mira A circumstellar
material and wind; the physical characteristics of mass transfer in
this system and especially the role of the accretion stream between
Mira A and Mira B; and the response of the system to the increased
accretion rate onto Mira B following the outburst. These results will
provide crucial inputs and quantitative constraints to models of wind
interacting systems and will also anchor our understanding of
accretion processes in a wide range of interacting binaries that
cannot be currently resolved, including in other symbiotics and more
exotic systems such as accreting black holes and neutron stars in
high-mass X-ray binaries.

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.

WFPC2 11134

WFPC2 Tidal Tail Survey: Probing Star Cluster Formation on the Edge

The spectacular HST images of the interiors of merging galaxies such
as the Antennae and NGC 7252 have revealed rich and diverse
populations of star clusters created over the course of the
interaction. Intriguingly, our WFPC2 study of tidal tails in these and
other interacting pairs has shown that star cluster birth in the tails
does not follow a similarly straightforward evolution. In fact,
cluster formation in these relatively sparse environments is not
guaranteed -- only one of six tails in our initial study showed
evidence for a significant population of young star clusters. The tail
environment thus offers the opportunity to probe star cluster
formation on the edge of the physical parameter space {e.g., of
stellar and gas mass, density, and pressure} that permits it to occur.
We propose to signficantly extend our pilot sample of optically
bright, gas-rich tidal tails by a factor of 4 in number to include a
more diverse population of tails, encompassing major and minor
mergers, gas-rich and gas-poor tails, as well as early, late, and
merged interaction stages. With 21 orbits of HST WFPC2 imaging in the
F606W and F814W filters, we can identify, roughly age-date, and
measure sizes of star clusters to determine what physical parameters
affect star cluster formation. WFPC2 imaging has been used effectively
in our initial study of four mergers, and it will be possible in this
program to reach similar limits of Mv=-8.5 for each of 16 more tails.
With the much larger sample we expect to isolate which factors, such
as merger stage, HI content, and merger mass ratio, drive the
formation of star clusters.

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.

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 wavelenghts 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.

WFPC2 11079

Treasury Imaging of Star Forming Regions in the Local Group:
Complementing the GALEX and NOAO Surveys

We propose to use WFPC2 to image the most interesting star-forming
regions in the Local Group galaxies, to resolve their young stellar
populations. We will use a set of filters including F170W, which is
critical to detect and characterize the most massive stars, to whose
hot temperatures colors at longer wavelengths are not sensitive.
WFPC2's field of view ideally matches the typical size of the
star-forming regions, and its spatial resolution allows us to measure
individual stars, given the proximity of these galaxies. The resulting
H-R diagrams will enable studies of star-formation properties in these
regions, which cover largely differing metallicities {a factor of 17,
compared to the factor of 4 explored so far} and characteristics. The
results will further our understanding of the star-formation process,
of the interplay between massive stars and environment, the properties
of dust, and will provide the key to interpret integrated measurements
of star-formation indicators {UV, IR, Halpha} available for several
hundreds more distant galaxies. Our recent deep surveys of these
galaxies with GALEX {FUV, NUV} and ground-based imaging {UBVRI,
Halpha, [OIII] and [SII]} provided the identification of the most
relevant SF sites. In addition to our scientific analysis, we will
provide catalogs of HST photometry in 6 bands, matched corollary
ground-based data, and UV, Halpha and IR integrated measurements of
the associations, for comparison of integrated star-formation indices
to the resolved populations. We envisage an EPO component.

NIC3 11064

CYCLE 15 NICMOS SPECTROPHOTOMETRY CALIBRATION PROGRAM

Now that the spectrophotometric capabilities of the NICMOS grism have
been established, cycle 15 observations are needed to refine the
sensitivity estimates, to check for sensitivity loss with time, to
improve the accuracy of the linearity correction, to improve the
secondary flux standards by re-observation, and to expand the G206
data set now that the sky subtraction technique has been shown to
produce useful fluxes for some of the fainter secondary standards.
These faint secondary IR standards will be a significant step towards
establishing flux standards for JWST, as well as for SNAP, Spitzer,
and SOFIA. 1.Re- observe the 3 primary WDs GD71, G191B2b, & GD153
twice each, once at the beginning and once near the end of the 18
month cycle. To date, we have only 2 observation of each star, while
the corresponding STIS data set for these primary standards ranges
from 6 to 23 obs. No observations exist for GD71 or GD153 with G206,
so that the current G206 sensitivity is defined solely by G191B2B.
Purposes: Refine sensitivities, measure sens losses. Orbits: 2 for
each of 6 visits = 12 2. Re-observe WD1057 & WD1657 plus another P041C
lamp-on visit to improve the scatter in the non-lin measurements per
Fig. 8 of NIC ISR 2006-02. The WD stars require 2 orbits each, while
the lamp-on test is done in one. The very faintest and most crucial
standard WD1657 has 2 good visits already, so to substantially improve
the S/N, two visits of two orbits are needed. Include G206 for P041C
in the lamp-off baseline part of that orbit. Orbits: WD1057-2,
WD1657-4, P041C-1 -- 7 3. Re-observe 9 secondary standards to improve
S/N of the faint ones and to include G206 for all 9. BD+17 {3 obs} is
not repeated in this cycle. Four are bright enough to do in one orbit:
VB8, 2M0036+18, P330E, and P177D. Orbits:2*5+4=14 Grand Total orbits
over 18 month cycle 15 is 12+6+14=32 {Roelof will submit the P041C
lamp-on visit in a separate program.}

NIC2 11016

NICMOS Flats: narrow and broad filters for NIC1 {+ NIC2, NIC3 in
parallel}

This proposal obtains sequences of NICMOS narrow band filter flat
fields for camera 1. In cameras 2 and 3, parallel observations will
allow us to obtain high S/N flats for all spectral elements.

WFPC2 10919

Eclipsing Binaries in the Local Group: II - Calibration of the
Zeropoint of the Cosmic Distance Scale and Fundamental Properties of
Stars in M33

(uses ACS/SBC and WFPC2)

The Great Spiral Galaxy in Triangulum {M33} is potentially a crucial
calibrator for the Cosmic Distance Scale, and thus for determining the
age and evolution of the Universe. M33 is viewed face-on, has a simple
geometry, large and diverse stellar populations, and morphologies
similar to our Galaxy and other more distant galaxies used for
distance determinations. Yet currently the M33 distance {d ~ 830 +/-
110 kpc} still has measurement dispersions of 10-15%. We have
demonstrated, in our work on the LMC and M31 distances, that
double-line eclipsing binaries can serve as excellent "standard
candles." Distances derived from eclipsing binaries are basically
geometric and essentially free from many assumptions and uncertainties
that plague other less direct methods, such as metallicity differences
and calibration zeropoints. The absolute radii of the component stars
of eclipsing binaries can be determined to better than a few percent
from the time- tested analyses of their light and radial velocity
curves. With accurate determinations of radii, temperatures, and ISM
absorption it is possible to determine reliable distances. We are
extending our program of using eclipsing binaries as standard candles
to determine an accurate distance to M33. As a first step, we are
proposing to carry out HST/ACS spectrophotometry of a well suited
~19th mag ~O7 + ~O7 eclipsing binary system in M33 that has been
previously observed from the ground. HST/ACS prism/grism
low-resolution spectrophotometry {118-850 nm} is the only missing key
element of this program and is used to determine more reliable values
for T_eff, [Fe/H], and ISM extinction. These quantities, when combined
with the results from existing light and radial velocity curves for
the target, yield the stellar masses, radii, luminosities and,
importantly, the distance. The proposed HST/ACS program can be carried
out effectively with only 1 HST orbit. Based on our previous
experience, we expect to reduce the uncertainty of the M33 distance to
better than 5-7%, thereby leading to a firmer calibration of the
Cosmic Distance Scale and the zeropoint of the Hubble Constant {Ho}.

WFPC2 10787

Modes of Star Formation and Nuclear Activity in an Early Universe
Laboratory

Nearby compact galaxy groups are uniquely suited to exploring the
mechanisms of star formation amid repeated and ongoing gravitational
encounters, conditions similar to those of the high redshift universe.
These dense groups host a variety of modes of star formation, and they
enable fresh insights into the role of gas in galaxy evolution. With
Spitzer mid-IR observations in hand, we have begun to obtain high
quality, multi-wavelength data for a well- defined sample of 12 nearby
{4500km/s} compact groups covering the full range of evolutionary
stages. Here we propose to obtain sensitive BVI images with the
ACS/WFC, deep enough to reach the turnover of the globular cluster
luminosity function, and WFPC2 U-band and ACS H-alpha images of
Spitzer-identified regions hosting the most recent star formation. In
total, we expect to detect over 1000 young star clusters forming
inside and outside galaxies, more than 4000 old globular clusters in
40 giant galaxies {including 16 early-type galaxies}, over 20 tidal
features, approximately 15 AGNs, and intragroup gas in most of the 12
groups. Combining the proposed ACS images with Chandra observations,
UV GALEX observations, ground-based H-alpha imaging, and HI data, we
will conduct a detailed study of stellar nurseries, dust, gas
kinematics, and AGN.

WFPC2 10766

A Deep X-ray Survey of the Small Magellanic Cloud

We request deep observations of 2 representative fields in the Small
Magellanic Cloud with Chandra and HST,with the primary goal of
measuring the luminosity function and space density of X-ray binaries
and other sources down to an unprecedented faint luminosity limit of
2x10E32 erg/s. This will be the faintest XLF ever obtained for any
galaxy, including our own. HST photometry to 24th magnitude in V and I
filters will identify the sources and provide Fx/Fopt, which will be
vital in quantifying the LMXB population and in measuring the
properties of the first coronally active stars ever detected in an
external galaxy.

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************** 18***************** 18
FGS REacq************** 20***************** 20
OBAD with Maneuver **** 72***************** 72

SIGNIFICANT EVENTS: (None)