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 #
4478
PERIOD COVERED: UT October 29, 2007 (DOY 302)
OBSERVATIONS SCHEDULED
ACS/SBC 10907
New Sightlines for the Study of Intergalactic Helium: A
Dozen
High-Confidence, UV-Bright Quasars from SDSS/GALEX
The reionization of intergalactic
helium is thought to have occurred
between redshifts
of about 3 and 4. Detailed study of HeII Lyman-alpha
absorption toward a handful quasars at
2.7<z<3.3 demonstrates the great
potential of such probes of the IGM, but
the current critically-small
sample limits confidence in resulting
cosmological inferences. The
requisite unobscured
quasar sightlines to high-redshift are extremely
rare, especially due to severe
absorption in random intervening
Lyman-limit systems, but SDSS provides thousands of z>3.1
quasars
potentially suitable for HeII studies. We have cross-correlated SDSS
quasars with GALEX UV sources to obtain
a dozen new, very
high-confidence, candidate quasars/sightlines
{z=3.1 to 4.1} potentially
useful for detailed HeII studies even with current HST instruments. We
propose brief, 2-orbit per target,
reconnaissance spectral exposures
with the ACS SBC prism to
definitively verify UV flux down to the HeII
break. Our combined SDSS/GALEX
selection insures a very high-yield of
confirmations, as the quasars are already
known to be UV-bright from
broadband GALEX images. The additional
sightlines, extending to very
high-redshift, will directly enable ensemble
spectral stacks, as well as
long exposure follow-up spectra, at
high S/N with the ACS/SBC
ultraviolet prisms {or perhaps STIS or COS later}, to confidently
measure the spectrum and evolution of
the ionizing background radiation,
the evolution of HeII opacity, and the density of intergalactic baryons.
FGS 11213
Distances to Eclipsing M Dwarf Binaries
We propose HST FGS observations to measure accurate
distances of 5
nearby M dwarf eclipsing binary
systems, from which model-independent
luminosities can be calculated. These
objects have either poor or no
existing parallax measurements. FGS
parallax determinations for these
systems, with their existing dynamic
masses determined to better than
0.5%, would serve as model-independent anchor points for
the low-mass
end of the mass-luminosity diagram.
NIC1/NIC2/NIC3 11330
NICMOS Cycle 16 Extended Dark
This takes a series of Darks in parallel to other
instruments.
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.
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.
WFPC2 11084
Probing the Least Luminous Galaxies in the Local Universe
We propose to obtain deep color-magnitude data of eight
new Local Group
galaxies which we recently discovered:
Andromeda XI, Andromeda XII, and
Andromeda XIII {satellites of M31}; Canes Venatici I, Canes Venatici II,
Hercules, and Leo IV {satellites of the Milky Way}; and
Leo T, a new
"free-floating" Local
Group dwarf spheroidal with evidence for recent
star formation and associated H I
gas. These represent the least
luminous galaxies known at *any* redshift, and are the only accessible
laboratories for studying this extreme
regime of galaxy formation. With
deep WFPC-2 F606W and F814W pointings at their centers, we will
determine whether these objects contain
single or multiple age stellar
populations, as well as whether these
objects display a range of
metallicities.
WFPC2 11119
The Stellar Origins of Supernovae
Supernovae {SNe} have a profound
effect on galaxies, and have been used
recently as precise cosmological probes,
resulting in the discovery of
the accelerating Universe. They are
clearly very important events
deserving of intense study. Yet, even
with nearly 4000 known SNe, we
know relatively little about the
stars which give rise to these powerful
explosions. The main limitation has been
the lack of spatial resolution
in pre-SN imaging data. However,
since 1999 our team has been at the
vanguard of directly identifying SN
progenitor stars in HST images. From
this exciting new line of study, the
emerging trend from 5 detections
for Type II-Plateau SNe is that their progenitors appear to be
relatively low mass {8 to 20 Msun} red supergiants, although
more cases
are needed. Nonetheless, the nature
of the progenitors of Type Ib/c SNe,
a subset of which are associated
with the amazing gamma-ray bursts,
remains ambiguous. Furthermore, we
remain in the continually
embarrassing situation that we still do not
yet know which progenitor
systems explode as Type Ia SNe, which are currently being
used for
precision cosmology. We propose to
confirm the identities of the
progenitors of 4 SNe
within 17 Mpc, which we expect to occur during
Cycle 16, through ToO observations using WFPC2/PC.
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 8 8
FGS REacq 5 5
OBAD with Maneuver
24 24
SIGNIFICANT EVENTS: (None)
-Lynn
____________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission Operations
Manager
CHAMP Flight Operations Team Manager
Lockheed Martin Mission Services (LMMS)
NASA GSFC PH#: 301-286-2876
"The Hubble Space Telescope is the
astronomical observatory and key to unlocking the most cosmic mysteries of the
past, present and future." - 7/26/6