Daily #3999

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #3999

PERIOD COVERED: UT November 01, 2005 (DOY 335)

OBSERVATIONS SCHEDULED

ACS/HRC 10545

Icy planetoids of the outer solar system

Early HST studies of satellites of Kuiper belt object focussed on the
50-200 km objects that were the largest known at the time. In the past
3 years we have discovered a population of much more rare and much
larger {500-2000+ km} icy planetoids in the Kuiper belt. These objects
are the largest and brightest known in the Kuiper belt and, in the era
when we now know of more than 1000 Kuiper belt objects, these few
planetoids are likely to be the focus of much of the research on
physical properties of the outer solar system for years to come. We
are currently engaged in an intensive program involving Spitzer, Keck,
and other telescopes to study the physical and dynamical properties of
this new population. HST is uniquely capable of addressing one
parameter fundamental to completing the physical picture of these
planetoids: the existence and size of any satellites. The detection
and characterization of satellites to these large planetoids would
allow us to address unique issues critical to the formation and
evolution of the outer solar system, including the measurement of
densities, internal properties, sizes and shapes of these objects, the
study of binary formation as a function of primary size, and the
context of the Pluto-Charon binary. For these bright objects, a
satellite search takes less than a full orbit, allowing the
opportunity for a new project on UV spectroscopy of the planetoids to
piggyback at no added time cost. This poorly explored spectral range
has the potential to show unique signatures of trapped gasses,
cosmochemically important ices, and complex organic materials.

ACS/WFC 10592

An ACS Survey of a Complete Sample 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 enhanced star formation and Active
Galactic Nuclei {AGN} activity, possibly triggered as the objects
transform into massive S0 and elliptical merger remnants. We propose
ACS/WFC imaging of a complete sample of 88 L_IR 10^11.4 L_sun
luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample
{RBGS: i.e., 60 micron flux density 5.24 Jy}. This sample is ideal
not only in its completeness and sample size, but also in the
proximity and brightness of the galaxies. The superb sensitivity,
resolution, and field of view of ACS/WFC on HST enables a unique
opportunity to study the detailed structure of galaxies that sample
all stages of the merger process. Imaging will be done with the F439W
and F814W filters {B and I-band} to examine as a function of both
luminosity and merger state {i} the evidence at optical wavelengths of
star formation and AGN activity and the manner in which instabilities
{bars and bridges} in the galaxies may funnel material to these active
regions, {ii} the relationship between star formation and AGN
activity, and {iii} the structural properties {AGN, bulge, and disk
components} and fundamental parameters {effective radius and surface
brightness} of LIRGs and their similarity with putative evolutionary
byproducts {elliptical, S0 and classical AGN host galaxies}. This HST
survey will also bridge the wavelength gap between a Spitzer imaging
survey {covering seven bands in the 3.6-160 micron range} and a GALEX
UV imaging survey of these galaxies, but will resolve complexes of
star clusters and multiple nuclei at resolutions well beyond the
capabilities of either Spitzer or GALEX. The combined datasets will
result in the most comprehensive multiwavelength study of interacting
and merging galaxies to date.

ACS/WFC 10618

The Light Echoes around V838 Monocerotis: MHD in 3 Dimensions,
Circumstellar Mapping, and Dust

V838 Monocerotis, which burst upon the astronomical scene in early
2002, is a completely unanticipated new object. It underwent a
large-amplitude and very luminous outburst, during which its spectrum
remained that of an extremely cool supergiant. A rapidly evolving set
of light echoes around V838 Mon was discovered soon after the
outburst, and quickly became the most spectacular display of the
phenomenon ever seen. The light echoes, which were imaged by us with
HST during 2002, provide the means to accomplish four unique types of
measurements based on continued HST imaging during the event: {1}
Study effects of MHD turbulence at high resolution and in 3
dimensions; {2} Construct the first unambiguous and fully 3-D map of a
circumstellar dust envelope in the Milky Way; {3} Study dust physics
in a unique setting where the spectrum and light curve of the
illumination, and the scattering angle, are unambiguously known; and
{4} Determine the distance to V838 Mon through two independent direct
geometric techniques {polarimetry and angular expansion rates}.
Because of the extreme rarity of light echoes, this is almost
certainly the only opportunity to achieve such results during the
lifetime of HST. We propose a campaign during Cycle 14 of imaging the
echoes every 8 days for a total of 6 epochs, in order to fully map a
thin slab through the dust shell and achieve the other goals listed
above.

ACS/WFC/HRC 10536

What Are Stalled Preplanetary Nebulae? An ACS SNAPshot Survey

Essentially all planetary nebulae {PNs} are aspherical, whereas the
mass-loss envelopes of AGB stars are strikingly spherical. Our
previous SNAPshot surveys of a morphologically unbiased sample of
pre-planetary nebulae {PPNs} -- objects in transition between the AGB
and PN evolutionary phases -- show that roughly half our observed
targets are resolved, with bipolar or multipolar morphologies.
Spectroscopic observations of our sample confirm that these objects
have not yet evolved into planetary nebulae. Thus, the transformation
from spherical to aspherical geometries has already fully developed by
the time these dying stars have become PPNs. Although our current
studies have yielded exciting results, they are limited in two
important ways -- {1} the number of well-resolved objects is still
small {18}, and the variety of morphologies observed relatively
multitudinous, hence no clear trends can yet be established between
morphology and other source properties {e.g., near-IR, far-IR colors,
stellar spectral type, envelope mass}, and {2} the current samples are
strongly biased towards small PPNs, as inferred from their low
60-to-25 micron flux ratios [R{60/25}1]. However, the prototype of
objects with R{60/25}1, the Frosty Leo Nebula, has a puzzlingly large
post-AGB age {almost 10^4 yr} and a fairly cool central star, very
different from the expectations of single-star stellar evolutionary
models. A proposed, but still speculative, hypothesis for such objects
is that the slow evolution of the central star is due to backflow of
material onto the mass-losing star, retarding its evolution towards
the PN phase. This hypothesis has significant consequences for both
stellar and nebular evolution. We therefore propose a survey of PPNs
with R{60/25}1 which is heavily weighted towards the discovery of
such "stalled PPNs". Supporting kinematic observations using long-slit
optical spectroscopy {with the Keck}, millimeter and radio
interferometric observations {with OVRO, VLA & VLBA} are being
undertaken. The results from this survey {together with our previous
work} will allow us to draw general conclusions about the complex
mass-outflow processes affecting late stellar evolution, and will
provide crucial input for theories of post-AGB stellar evolution. Our
survey will produce an archival legacy of long-standing value for
future studies of dying stars.

ACS/WFC/NIC3/WFPC2 10530

Probing Evolution And Reionization Spectroscopically {PEARS}

While imaging with HST has gone deep enough to probe the highest
redshifts, e.g. the GOODS survey and the Ultra Deep Field,
spectroscopic identifications have not kept up. We propose an ACS
grism survey to get slitless spectra of all sources in a wide survey
region {8 ACS fields} up to z =27.0 magnitude, and an ultradeep field
in the HUDF reaching sources up to z =28 magnitude. The PEARS survey
will: {1} Find and spectrocopically confirm all galaxies between
z=4-7. {2} Probe the reionization epoch by robustly determining the
luminosity function of galaxies and low luminosity AGNs at z = 4 - 6.
With known redshifts, we can get a local measure of star formation and
ionization rate in case reionization is inhomogeneous. {3} Study
galaxy formation and evolution by finding galaxies in a contiguous
redshift range between 4 z 7, and black hole evolution through a
census of low-luminosity AGNs. {4} Get a robust census of galaxies
with old stellar populations at 1 z 2.5, invaluable for checking
consistency with heirarchical models of galaxy formation. Fitting
these galaxies' spectra will yield age and metallicity estimates. {5}
Study star-formation and galaxy assembly at its peak at 1 z 2 by
identifying emission lines in star-forming galaxies, old populations
showing the 4000A break, and any combination of the two. {6} Constrain
faint white dwarfs in the Galactic halo and thus measure their
contribution to the dark matter halo. {7} Derive spectro-photometric
redshifts by using the grism spectra along with broadband data. This
will be the deepest unbiased spectroscopy yet, and will enhance the
value of the multiwavelength data in UDF and the GOODS fields to the
astronomical community. To this end we will deliver reduced spectra to
the HST archives.

NICMOS 8791

NICMOS Post-SAA calibration - CR Persistence Part 2

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 10501

Extending the Heritage: Clusters, Dust, and Star Formation in M51

Strongly interacting systems in the Local Universe offer the
opportunity to investigate the modality of star formation under
dynamical conditions more typical of the intermediate redshift
Universe {z~0.5-1}, at an exquisite resolution unmatched by distant
galaxies. M51 is one such system. Most recently, the Hubble Heritage
program dedicated 24 HST orbits to obtain a 3X2 ACS mosaic of M51 in
BVI, and Halpha. While this is designed to produce a lovely
multi-color image of this photogenic target, its scientific return
will be limited for star formation studies. Hence we propose to
augment these observations by obtaining WFPC2 U band and NICMOS H band
primary imaging {with NICMOS Paschen alpha in parallel} of selected
pointings of this interacting galaxy system. At the modest cost of 14
additional orbits, we will: {1} accurately determine the ages of the
young star cluster population; {2} secure the identification of 60-70
old globular clusters; {3} search for heavily dust enshrouded stellar
clusters; {4} investigate the distribution of the cluster populations
as a function of location {galactocentric, arms, interarms, etc.}; and
{5} both remove the effects of dust and determine its properties. In
addition to our specific science goals, these observations lend
themselves, on their own or in synergy with data from GALEX and
Spitzer, to a host of other investigations, including those on evolved
diffuse stellar populations, galactic structure, and dust radiative
transfer. We will thus release these data early to the community, by
relinquishing part of the proprietary period.

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:
17598-0 - FHST SOB Macro Load @335/1442z
17600-0 - Genslew for Prop 10696 - Slot#1 @335/1802z
17601-0 - Genslew for Prop 10696 - Slot#2 @335/1804z
17602-0 - Genslew for Prop 10696 - Slot#6 @335/1805z
17603-0 - Genslew for Prop 10696 - Slot#5 @335/1807z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 07 07
FGS REacq 07 07
OBAD with Maneuver 20 20

SIGNIFICANT EVENTS:

Ops Request 17598 was successfully executed at 14:41:03 on day 335 to
uplink on-orbit macro for the FHST 2 and 3 "Stuck on Bottom" (SOB).
The table was dumped, compared, and verified via CCS dump comparison.