Daily Report #4639

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4639

PERIOD COVERED: 5am June 24 - 5am June 25, 2008 (DOY 176/0900z-177/0900z)

OBSERVATIONS SCHEDULED

ACS/SBC 11110

Searching for Lyman Apha Emission from FUSE Lyman Continuum Candidates

We have recently been granted time on FUSE to characterize the escape
fraction of hydrogen Lyman continuum (Lyc) photons from a morphologically
diverse set of star forming galaxies. The FUSE program is designed to
provide ~ 5 sigma detections of Lyc photons emitted from star forming
galaxies with escape fractions ~5%. With this proposal we seek hydrogen
Lyman alpha (Lya) observations of a representative subset of the FUSE
program targets to constrain the observational relationship between Lyc,
Lya, and hydrogen Balmer line emission in these systems. Such observations
explore the detailed balance between the simple optically thin (Case A) and
optically thick (Case B) limits in recombination theory. The ultimate goal
of this program is to quantify the relationship between escaping Lya and Lyc
emission and the first structures that form in the early universe.

NIC1 11136

Resolving Ultracool Astrophysics with Brown Dwarf Binaries

We propose to obtain resolved far-red and near-IR photometry of 13 brown
dwarf binaries with HST/NICMOS in order to study one of the long-standing
puzzles in ultracool astrophysics, namely the rapid change in spectra from L
dwarfs to T dwarfs at nearly constant effective temperature (a.k.a. the "L/T
transition''). While many nearby brown dwarfs have been studied, use of such
samples is inevitably hindered by the unknown ages, masses, and
metallicities of the field population. Characterization of resolved
ultracool binaries is a promising avenue for addressing this problem, by
providing coeval systems of the same composition with comparable masses and
temperatures. Our proposed HST/NICMOS (0.9-1.6 micron) observations will be
combined with longer wavelength ground-based photometry and spectroscopy
from Keck laser guide star adaptive optics. The resulting multiband (0.9-2.5
micron) dataset will be a unique resource for measuring the evolution of
spectral energy distributions across the L/T transition, to test
state-of-the-art atmospheric models, and to determine the physical
process(es) that dominate the L/T transition. Understanding the L/T
transition is important not only for testing brown dwarf atmospheres, but
also provides a key pathway for understanding the same physical effects,
namely the formation and removal of clouds, in the atmospheres of the
extrasolar planets.

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 images. Each observation will need its own CRMAP, as
different SAA passages leave different imprints on the NICMOS detectors.

NIC2 11237

The Origin of the Break in the AGN Luminosity Function

We propose to use NICMOS imaging to measure rest-frame optical luminosities
and morphological properties of a complete sample of faint AGN host galaxies
at redshifts z ~ 1.4. The targets are drawn from the VLT-VIMOS Deep Survey,
and they constitute a sample of the lowest luminosity type 1 AGN known at z
1. The spectroscopically estimated black hole masses are up to an order of
magnitude higher than expected given their nuclear luminosities, implying
highly sub-Eddington accretion rates. This exactly matches the prediction
made by recent theoretical models of AGN evolution, according to which the
faint end of the AGN luminosity function is populated mainly by big black
holes that have already exhausted a good part of their fuel. In this
proposal we want to test further predictions of that hypothesis, by
focussing on the host galaxy properties of our low-luminosity, low-
accretion AGN. If the local ratio between black hole and bulge masses holds
at least approximately at these redshifts, one expects most of these
low-luminosity AGN to reside in fairly big ellipticals with stellar masses
around and above 10^11 solar masses (in contrast to the Seyfert phenomenon
in the local universe). With NICMOS imaging we will find out whether that is
true, implying also a sensitive test for the validity of the M_BH/M_bulge
relation at z ~ 1.4.

NIC3/WFPC2 11192

NICMOS Confirmation of Candidates of the Most Luminous Galaxies at z 7

While the deepest pencil-beam near-IR survey suggested that the Universe was
too young to build up many luminous galaxies by z ~ 7--8 (Bouwens &
Illingworth 2006), there is also evidence indicating the contrary. It is now
known that some galaxies with stellar masses of M1e10 Msun were already in
place by z ~ 6--7, which strongly suggests that their progenitors should be
significantly more luminous, and hence detectable in deep, wide-field
near-IR surveys (Yan et al. 2006). As galaxies at such a high redshift
should manifest themselves as "dropouts" from the optical, we have carried
out a very wide-field, deep near-IR survey in the GOODS fields to search for
z-band dropouts as candidates of galaxies at z 7. In total, six promising
candidates have been found in ~ 300 sq. arcmin to J_AB ~ 24.5 mag
(corresponding to restframe M(UV) -22.5 mag at z ~ 7). By contrast, the
galaxy luminosity function (LF) suggested in BI06 would predict at most 3--5
galaxies over the entire 2-pi sky at this brightness level. Here we propose
to observe these candidates with NIC3 in F110W and F160W to further
investigate their nature. If any of these candidates are indeed at z 7,
the result will lead to a completely new picture of star formation in the
early universe. If none of our candidates are consistent with being at z
7, then the depth and area of our near-IR survey (from which the candidates
are drawn) will let us set a very stringent upper limit on the bright end of
the galaxy LF at those redshift. As a result, our program will still be able
to provide new clues about the processes of early galaxy formation, such as
their dust contents and their merging time scale (Yan et al. 2006).

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11352 - GSacq(2,1,2) loss of lock while guiding.

GSacq(2,1,2)scheduled at 176/20:55:56 was successful. At 21:17:13
GSacq(2,1,2) lost lock. Stop flags(QF2STOPF, QF1STOPF, QSTOP) were set on
FGS 2 & FGS 1. There were no STB or ESB messages. TERM EXP was not scheduled
until 21:40:08.

Possible Observations affected: NIC 144 Proposal ID#11237

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL FAILURE TIMES

FGS GSacq 04 04
FGS REacq 08 08
OBAD with Maneuver 24 24
LOSS of LOCK 176/21:17:13z

SIGNIFICANT EVENTS: (None)