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 i
mages.
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 M>1e10 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)