Status Report

NASA Hubble Space Telescope Daily Report # 3566

By SpaceRef Editor
March 10, 2004
Filed under , ,


HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




ACS 9984

Cosmic Shear With ACS Pure Parallels

Small distortions in the shapes of background galaxies by foreground
mass provide a powerful method of directly measuring the amount and
distribution of dark matter. Several groups have recently detected
this weak lensing by large-scale structure, also called cosmic shear.
The high resolution and sensitivity of HST/ACS provide a unique
opportunity to measure cosmic shear accurately on small scales. Using
260 parallel orbits in Sloan textiti {F775W} we will measure for the
first time: beginlistosetlength sep0cm setlengthemsep0cm setlength
opsep0cm em the cosmic shear variance on scales <0.7 arcmin, em the
skewness of the shear distribution, and em the magnification effect.
endlist Our measurements will determine the amplitude of the mass
power spectrum sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20,
and the mass density Omega_m with s/n=4. They will be done at small
angular scales where non-linear effects dominate the power spectrum,
providing a test of the gravitational instability paradigm for
structure formation. Measurements on these scales are not possible
from the ground, because of the systematic effects induced by PSF
smearing from seeing. Having many independent lines of sight reduces
the uncertainty due to cosmic variance, making parallel observations

ACS/HRC 10050

ACS Earth Flats

High signal 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 used by the pipeline and will provide
a comparison with flats derived via other techniques: L-flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronographic
monitoring is required to assess the changing position of the spots.


CCD Daily Monitor

This program consists of basic tests to monitor, the read noise, the
development of hot pixels and test for any source of noise in ACS CCD
detectors. This programme will be executed once a day for the entire
lifetime of ACS.

ACS/WFC 9575

Default {Archival} Pure Parallel Program.

The Advanced Camera for Surveys (WFC) was used to test ACS pure
parallels in POMS.


The local Hubble flow and the density field within 6 Mpc

Great progress has been made recently in accurate distance
measurements of nearby galaxies beyond the Local Group based on the
luminosity of the tip of the red giant branch {TRGB}. Over the last
three years, snapshot surveys with HST have provided us with the TRGB
distances for more than a hundred nearby galaxies obtained with an
accuracy of about 10%. The local velocity field within 5 Mpc exhibits
a significant anisotropy which disagrees with a spherical
Virgo-centric flow. The local Hubble flow is very cold, with 1-D rms
deviations of ~30 km/s. Cosmological simulations with Cold Dark Matter
can only realize such low dispersions with a combination of a low mean
density of matter and a substantial component with negative pressure.
There may be a constraint on the equation of state w=-p/rho. Our
observations will concentrate on 116 galaxies whose expected distances
lie within 4 – 6 Mpc, allowing us to trace a Dark Matter distribution
in the Local Volume with twice the information currently available.
The program is a good one for SNAP mode because the order and rate
that the observations are made are not very important, as long as
there is good completion over several years.


The COSMOS 2-Degree ACS Survey

We will undertake a 2 square degree imaging survey {Cosmic Evolution
Survey — COSMOS} with ACS in the I {F814W} band of the VIMOS
equatorial field. This wide field survey is essential to understand
the interplay between Large Scale Structure {LSS} evolution and the
formation of galaxies, dark matter and AGNs and is the one region of
parameter space completely unexplored at present by HST. The
equatorial field was selected for its accessibility to all
ground-based telescopes and low IR background and because it will
eventually contain ~100, 000 galaxy spectra from the VLT-VIMOS
instrument. The imaging will detect over 2 million objects with I> 27
mag {AB, 10 sigma}, over 35, 000 Lyman Break Galaxies {LBGs} and
extremely red galaxies out to z ~ 5. COSMOS is the only HST project
specifically designed to probe the formation and evolution of
structures ranging from galaxies up to Coma-size clusters in the epoch
of peak galaxy, AGN, star and cluster formation {z ~0.5 to 3}. The
size of the largest structures necessitate the 2 degree field. Our
team is committed to the assembly of several public ancillary datasets
including the optical spectra, deep XMM and VLA imaging, ground-based
optical/IR imaging, UV imaging from GALEX and IR data from SIRTF.
Combining the full-spectrum multiwavelength imaging and spectroscopic
coverage with ACS sub-kpc resolution, COSMOS will be Hubble’s ultimate
legacy for understanding the evolution of both the visible and dark

NIC/NIC3 9865

The NICMOS Parallel Observing Program

We propose to continue managing the NICMOS pure parallel program.
Based on our experience, we are well prepared to make optimal use of
the parallel opportunities. The improved sensitivity and efficiency of
our observations will substantially increase the number of
line-emitting galaxies detected. As our previous work has
demonstrated, the most frequently detected line is Halpha at
0.7<z<1.9, which provides an excellent measure of current star
formation rate. We will also detect star-forming and active galaxies
in other redshift ranges using other emission lines. The grism
observations will produce by far the best available Halpha luminosity
functions over the crucial–but poorly observed–redshift range where
galaxies appear to have assembled most of their stellar mass. This key
process of galaxy evolution needs to be studied with IR data; we found
that observations at shorter wavelengths appear to have missed a large
fraction of the star-formation in galaxies, due to dust reddening. We
will also obtain deep F110W and F160W images, to examine the space
densities and morphologies of faint red galaxies. In addition to
carrying out the public parallels, we will make the fully reduced and
calibrated images and spectra available on-line, with some
ground-based data for the deepest parallel fields included.

NIC3 9999

The COSMOS 2-Degree ACS Survey NICMOS Parallels

The COSMOS 2-Degree ACS Survey NICMOS Parallels. This program is a
companion to program 9822.


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.

STIS/CCD 10017

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD.

STIS/CCD 10019

CCD Bias Monitor – Part 1

Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1,
and 1×1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns.

STIS/CCD 10085

STIS Pure Parallel Imaging Program: Cycle 12

This is the default archival pure parallel program for STIS during
cycle 12.


The Physical Character of the Smallest-Scale Interstellar Structures

The origin{s} of interstellar structure recently seen on very small
{tens of AU} scales is a puzzle that has inspired a number of possible
theoretical interpretations. In particular, fluctuations in density
and/or ionization fraction which can arise naturally in a turbulent
medium may give rise to the observed structure. We propose to use STIS
to accurately measure and compare selected interstellar absorption
line profiles toward two binary star systems to test specific
predictions of these models. In addition to NaI line profile
variations between the stars indicative of structure on scales of
~2000 to 5000 AU, one member of each system shows temporal {proper
motion induced} variations in one component indicative of structure on
scales of ~20 AU. Such temporally variable components allow one to
explore the structure of the interstellar medium on the smallest
scales, and a detailed physical understanding of these structures
requires the diagnostic power of the many interstellar species
observable in the ultraviolet. By re-observing the HD 32039/40 system
we will be able to confirm or invalidate our {turbulence inspired}
model for the origin of this particular temporal fluctuation. The HD
36408AB system will allow us to study two locations near the edge of
an individual cloud, and provide a new understanding of the surface
layers of interstellar clouds.

STIS/MA1/MA2 9739

Are We Missing the Dominant Sites of Star Formation in Local UV-Bright

We propose to explore the ages, extinctions, and masses of young
stellar clusters in four nearby dwarf starburst galaxies {He 2-10, NGC
5253, NGC 4214, and IIZw40}. We will combine available archival data
with new, high resolution HST observations from the ultraviolet to the
infrared. All four galaxies are known from ground based radio/infrared
observations to contain highly obscured, massive stellar clusters,
which dominate the far infrared flux. Despite the fact that almost all
of the infrared flux comes from regions which are obscured at UV and
optical wavelengths, these galaxies are consistent with the well known
correlation between the UV slope {beta} and the ratio of far infrared
flux to ultraviolet flux at 1600 Angstroms. Because the UV and IR
fluxes are decoupled, this observation implies that a simple
foreground screen model, where UV photons from hot stars are
reprocessed into the infrared by local dust, is not the proper
interpretation for why these galaxies follow the beta relation. We
propose to investigate the underlying mechanisms responsible for this
observed correlation in these UV bright galaxies, and explore the
implication for high redshift starbursts.

WFPC2 10070

WFPC2 CYCLE 12 Supplemental Darks Part 2/3

This dark calibration program obtains 3 dark frames every day to
provide data for monitoring and characterizing the evolution of hot

WFPC2 10084

WFII parallel archive proposal

This is the generic target version of the WFPC2 Archival Pure Parallel
program. The program will be used to take parallel images of random
areas of the sky, following the recommendations of the 2002 Parallels
Working Group.

WFPC2 9634

POMS Test Proposal: WFII targeted parallel archive proposal

The parallel opportunities available with WFPC2 in the neighborhood of
bright galaxies are treated in a slightly different way from the
normal pure parallels. Local Group galaxies offer the opportunity for
a closer look at young stellar populations. Narrow-band images in
F656N can be used both to identify young stars via their emission
lines, and to map the gas distribution in star-forming regions. Thus,
the filter F656N is added to the four standard filters. Near more
distant galaxies, up to about 10 Mpc, we can map the population of
globular clusters; for this purpose, F300W is less useful, and only
F450W, F606W, and F814W will be used.


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

HSTAR 9349: During LOS, NICMOS suspended @ 069/14:02:42Z due to an
Intel Debug Exception with Status Buffer Message 104, Parameter 2,
Time 32482 received. At the time NICMOS was executing Proposal 09999.
Under investigation.

17095-0 Dump NICMOS Memory after Suspend @ 069/16:43z
17096-4 NICMOS Suspend Recovery @ 069/18:25z


                         SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq             11                        11
FGS REacq             06                         06
FHST Update           12                         12


NICMOS suspended (during LOS) @ 069/14:02:42Z due to an Intel Debug
Exception, received Status Buffer Message 104, Parameter 2, Time
32482. At the time of the suspend, NICMOS was executing Proposal
09999 "The COSMOS 2-Degree ACS Survey NICMOS Parallels". See HSTAR
9349. Following NICMOS Suspend, dumped NICMOS memory @ 069/16:43Z (OR
17995 and ROP NS-9). Successfully recovered NICMOS to Operate mode
with FOM moves @ 069/18:21Z (OR 17096 and excerpts from COP 19.12).

Command Timing test scheduled 070/12:00Z – 22:00Z with GDOC, SOC,
HITT, and CCS using CCS "H"String with CCS Release and PRD
O6300ST. The purpose of this testing is to check the command timing
for CCS Release with historical, baselined numbers.

O’Keefe, Beckwith, and Zubrin to Debate Hubble on CNN Tonight March 9,
2004 Mars Society President Dr. Robert Zubrin, Space Telescope Science
Institute Director Dr. Steve Beckwith, and NASA Administrator Mr. Sean
O’Keefe will discuss the Hubble Space Telescope on CNN tonight. At
issue is Mr. O’Keefe’s controversial decision to desert the space
telescope. Both Dr. Zubrin and Dr. Beckwith oppose Hubble abandonment.
The show will air twice, first within the Anderson Cooper newshour
beginning at 7 PM EST, and then again during the Aaron Brown newshour
which starts at 10 PM EST.

SpaceRef staff editor.