Daily #3983

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3983

PERIOD COVERED: UT November 7, 2005 (DOY 311)

OBSERVATIONS SCHEDULED

ACS/HRC 10525

Characterizing the Near-UV Environment of M Dwarfs: Implications for
Extrasolar Planetary Searches and Astrobiology

We propose SNAP observations with the ACS HRC PR200L prism, designed to
measure the near ultraviolet emission in a sample of 107 nearby M
dwarfs. The sample spans the mass range from 0.1 - 0.6 solar masses
{temperature range 2200K - 4000K} where the UV energy distributions vary
widely between active and inactive stars. The strength and distribution
of this UV emission can have critical consequences for the atmospheres
of attendant planets. Our proposed observations will provide desperately
needed constraints on models of the habitability zone and the
atmospheres of possible terrestrial planets orbiting M dwarf hosts, and
will be used to sharpen TPF target selection. In addition, the NUV data
will be used in conjunction with existing optical, FUV and X-ray data to
constrain a new generation of M dwarf atmospheric models, and to explore
unanswered questions regarding the dynamo generation and magnetic
heating in these low-mass stars.

ACS/HRC 10556

Neutral Gas at Redshift z=0.5

Damped Lyman-alpha systems {DLAs} are used to track the bulk of the
neutral hydrogen gas in the Universe. Prior to HST UV spectroscopy, they
could only be studied from the ground at redshifts z1.65. However, HST
has now permitted us to discover 41 DLAs at z1.65 in our previous
surveys. Followup studies of these systems are providing a wealth of
information about the evolution of the neutral gas phase component of
the Universe. But one problem is that these 41 low-redshift systems are
spread over a wide range of redshifts spanning nearly 70% of the age of
the Universe. Consequently, past surveys for low-redshift DLAs have not
been able to offer very good precision in any small redshift regime.
Here we propose an ACS-HRC- PR200L spectroscopic survey in the redshift
interval z=[0.37, 0.7] which we estimate will permit us to discover
another 41 DLAs. This will not only allow us to double the number of
low-redshift DLAs, but it will also provide a relatively high-precision
regime in the low-redshift Universe that can be used to anchor
evolutionary studies. Fortunately DLAs have high absorption equivalent
width, so ACS-HRC-PR200L has high-enough resoultion to perform this
proposed MgII-selected DLA survey.

ACS/HRC 10738

Earth Flats

Sky flats will be obtained by observing the bright Earth with the HRC
and WFC. These observations will be used to verify the accuracy of the
flats currently in the pipeline and to monitor any changes. Weekly
coronagraphic monitoring is required to assess the changing position of
the spots.

ACS/HRC 10770

Hubble Heritage Observations of Mars at 2005 Opposition and Closest
Approach.

The Hubble Heritage team will obtain images of Mars during the 2005
closest approach and opposition. On October 28th, 2005, ACS HRC
observations of Mars will be taken, corresponding to a time nearest
closest approach. On November 7th, 2005, WFPC2 images of Mars will be
taken, to add data to the 10 year WFPC2 imaging of Mars as well as to
have an image of the planet at opposition. Both datasets will be used
for a public release image.

ACS/HRC/WFC 10729

ACS CCDs daily monitor

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise in
ACS CCD detectors. The files, biases and dark will be used to create
reference files for science calibration. This programme will be for the
entire lifetime of ACS. Changes from cycle 13:- The default gain for WFC
is 2 e-/DN. As before bias frames will be collected for both gain 1 and
gain 2. Dark frames are acquired using the default gain {2}. This
program cover the period Oct, 2 2005- May, 29-2006. The second half of
the program has a different proposal number: 10758.

ACS/WFC 10494

Imaging the mass structure of distant lens galaxies

The surface brightness distribution of extended gravitationally lensed
arcs and Einstein rings contains super-resolved information about the
lensed object, and, more excitingly, about the smooth and clumpy mass
distribution of the lens galaxies. The source and lens information can
non-parametrically be separated, resulting in a direct
"gravitational-mass image" of the inner mass-distribution of
cosmologically-distant galaxies {Koopmans 2005}. With this goal in mind,
we propose deep HST ACS-F555W/F814W and NICMOS-F160W imaging of 15
gravitational-lens systems with spatially resolved lensed sources,
selected from the 17 new lens systems discovered by the Sloan Lens ACS
Survey {Bolton et al. 2004}. Each system has been selected from the SDSS
and confirmed in a time-efficient HST-ACS snapshot program {cycle-13};
they show highly-magnified arcs or Einstein rings, lensed by a massive
early-type lens galaxy. High- fidelity multi-color HST images are
required {not delivered by the 420-sec snapshot images} to isolate these
lensed images {properly cleaned, dithered and extinction-corrected} from
the lens galaxy surface brightness distribution, and apply our
"gravitational-mass imaging" technique. The sample of galaxy mass
distributions - determined through this method from the arcs and
Einstein ring HST images - will be studied to: {i} measure the smooth
mass distribution of the lens galaxies {Dark and luminous mass are
separated using the HST images and the stellar M/L values derived from a
joint stellar-dynamical analysis of each system}; {ii} quantify
statistically and individually the incidence of mass-substructure {with
or without obvious luminous counter- parts such as dwarf galaxies}.
Since dark-matter substructure should be considerably more prevalent at
higher redshift, both results provide a direct test of this prediction
of the CDM hierarchical structure-formation model.

ACS/WFC 10523

The Halo Shape and Metallicity of Massive Spiral Galaxies

We propose to resolve the stellar populations of the halos of seven
nearby, massive disk galaxies using a SNAP survey with WFC/ACS. These
observations will provide star counts and color-magnitude diagrams 2-3
magnitudes below the tip of the Red Giant Branch along the two principal
axes and one intermediate axis of each galaxy. We will measure the
metallicity distribution functions and stellar density profiles from
star counts down to very low average surface brightnesses, equivalent to
~31 V-mag per square arcsec. This proposal will create a unique sampling
of galaxy halo properties, as our targets cover a range in galaxy mass,
luminosity, inclination, and morphology. As function of these galaxy
properties this survey will provide:- the first systematic measurement
of radial light profiles and axial ratios of the diffuse stellar halos
and outer disks of spiral galaxies- a comprehensive analysis of halo
metallicity distributions as function of galaxy type and position within
the galaxy- an unprecedented study of the stellar metallicity and age
distribution in the outer disk regions where the disk truncations occur-
the first comparative study of globular clusters and their field stellar
populations We will use these fossil records of the galaxy assembly
process to test halo formation models within the hierarchical galaxy
formation scheme.

ACS/WFC/NIC3 10632

Searching for galaxies at z6.5 in the Hubble Ultra Deep Field

We propose to obtain deep ACS {F606W, F775W, F850LP} imaging in the area
of the original Hubble Ultra Deep Field NICMOS parallel fields and -
through simultaneous parallel observations - deep NICMOS {F110W, F160W}
imaging of the ACS UDF area. Matching the extreme imaging depth in the
optical and near-IR bands will result in seven fields with sufficiently
sensitive multiband data to detect the expected typical galaxies at z=7
and 8. Presently no such a field exist. Our combined optical and near-IR
ultradeep fields will be in three areas separated by about 20 comoving
Mpc at z=7. This will allow us to give a first assessment of the degree
of cosmic variance. If reionization is a process extending over a large
redshift interval and the luminosity function doesn't evolve strongly
beyond z=6, these data will allow us to identify of the order of a dozen
galaxies at 6.5z8.5 - using the Lyman break technique - and to place a
first constrain on the luminosity function at z6.5. Conversely, finding
fewer objects would be an indication that the bulk of reionization is
done by galaxies at z=6. By spending 204 orbits of prime HST time we
will capitalize on the investment of 544 prime orbits already made on
the Hubble Ultra Deep Field {UDF}. We have verified that the program as
proposed is schedulable and that it will remain so even if forced to
execute in the 2-gyro mode. The data will be non-proprietary and the
reduced images will be made public within 2 months from the completion
of the observations.

FGS 10610

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric
elements {perturbation orbit semi-major axis and inclination} of
extra-solar planets orbiting six stars. These companions were originally
detected by radial velocity techniques. We have demonstrated that FGS
astrometry of even a short segment of reflex motion, when combined with
extensive radial velocity information, can yield useful inclination
information {McArthur et al. 2004}, allowing us to determine companion
masses. Extrasolar planet masses assist in two ongoing research
frontiers. First, they provide useful boundary conditions for models of
planetary formation and evolution of planetary systems. Second, knowing
that a star in fact has a plantary mass companion, increases the value
of that system to future extrasolar planet observation missions such as
SIM PlanetQuest, TPF, and GAIA.

NIC1/NIC3 10726

NICMOS non-linearity tests

This program incorporates a number of tests to analyse the count rate
dependent non-linearity seen in NICMOS spectro-photometric observations.
In visit 1 we will observe a few fields with stars of a range in
luminosity in NGC1850 with NICMOS in NIC1 in F090M, F110W and F160W and
NIC2 F110W, F160W, and F180W. We will repeat the observations with
flatfield lamp on, creating artificially high count-rates, allowing
tests of NICMOS linearity as function of count rate. To access the
effect of charge trapping and persistence, we first take darks {so there
is not too much charge already trapped}, than take exposures with the
lamp off, exposures with the lamp on, and repeat at the end with lamp
off. Finally, we continue with taking darks during occultation. In visit
2 we will observe spectro-photometric standard P041C using the G096 and
G141 grisms in NIC3, and repeat the lamp off/on/off test to artificially
create a high background. In visits 3&4 we repeat photometry
measurements of faint standard stars SNAP-2 and WD1657+343, on which the
NICMOS non-linearity was originally discovered using grism observations.
These measurements are repeated, because previous photometry was
obtained with too short exposure times, hence substantially affected by
charge trapping non-linearity. Measurements will be made with NIC1:
Visit 5 forms the persistence test of the program. The bright star
GL-390 {used in a previous persistence test} will iluminate the 3 NICMOS
detectors in turn for a fixed time, saturating the center many times,
after which a series of darks will be taken to measure the persistence
{i.e. trapped electrons and the decay time of the traps}. To determine
the wavelength dependence of the trap chance, exposures of the bright
star in different filters will be taken, as well as one in the G096
grism with NIC3. Most exposures will be 128s long, but two exposures in
the 3rd orbit will be 3x longer, to seperate the effects of count rate
versus total counts of the trap probability {in one exposure, we get the
full PSF worth of count rates, but we need a longer exposure to separate
the effect of rate versus total couts}. Filters used: NIC1 F090M, F110W,
F170M and F160W; NIC2 F110W, F160W, F205W, F187W; NIC3 G096, F110W,
F160W; 3x longer exposures: NIC1 and NIC2 F110W.

NICMOS 8790

NICMOS Post-SAA calibration - CR Persistence Part 1.

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.

WFPC2 10748

WFPC2 CYCLE 14 Standard Darks

This dark calibration program obtains dark frames every week in order to
provide data for the ongoing calibration of the CCD dark current rate,
and to monitor and characterize the evolution of hot pixels. Over an
extended period these data will also provide a monitor of radiation
damage to the CCDs.

WFPC2 10751

WFPC2 CYCLE 14 Intflat Linearity Check and Filter Rotation Anomaly
Monitor

Intflat observations will be taken to provide a linearity check: the
linearity test consists of a series of intflats in F555W, in each gain
and each shutter. A combination of intflats, visflats, and earthflats
will be used to check the repeatability of filter wheel motions.
{Intflat sequences tied to decons, visits 1-18 in prop 10363, have been
moved to the cycle 14 decon proposal 10744 for easier scheduling.} Note:
long-exposure WFPC2 intflats must be scheduled during ACS anneals to
prevent stray light from the WFPC2 lamps from contaminating long ACS
external exposures.

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 08 08
FGS REacq 05 05
OBAD with Maneuver 24 24

SIGNIFICANT EVENTS: (None)