Status Report

Hubble Space Telescope Daily Report # 3182 20 Aug 2002

By SpaceRef Editor
August 20, 2002
Filed under , ,




OBSERVATIONS SCHEDULED (see HSTARS below for possible observation problems)


NICMOS Post-SAA calibration – CR Persistence Part 1.

A new procedure proposed to alleviate the CR-persistence problem of NICMOS.
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
darks will be non-standard reference files available to users with a USEAFTER
date/time mark.


Dark Monitor-Part 2.

The Space Telescope Imaging Spectrograph (CCD) was used to monitor the darks.


Bias Monitor-Part 2.

The Space Telescope Imaging Spectrograph (CCD) was used to 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 in order
to build up high-S/N superbiases and track the evolution of hot columns.

STIS/MA1/MA2 8920

Cycle 10 MAMA Dark Measurements.

the MAMA detector dark noise, and is the primary means of checking on health of
the MAMA detectors systems through frequent monitoring of the background count

WF/PC-2 8935

Cycle 10 Standard Darks.

The WF/PC-2 was used to obtain 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 8938


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

WF/PC-2 8939

Cycle 10 Internal Monitor.

The WF/PC-2 was used to calibrate the internal monitor, to be run weekly to
monitor the health of the cameras.

STIS 9035

Spatially Resolved Spectroscopy of Uranus and Neptune

We propose to use STIS to obtain data cubes for Uranus {Cycle 10} and Neptune
{Cycle 11}. The spectrum between 290 and 1020 nm is sampled at 2000
The north-south position on the planetary disk is sampled along the slit every
0.05″. The east-west position is sampled by successive exposures every 0.05″
{longward of 520 nm wavelength} and 0.15″ {shortward of 520 nm}. Such data have
never been obtained. Only HST, with STIS, has the capability to record spatial
variations of narrow methane and hydrogen absorption and Raman scattering
features. We have obtained such data for Saturn by ground-based observations
which permitted a comprehensive understanding of the vertical haze and cloud
structure as a function of latitude. Similar improvements are expected from the
proposed data for Uranus and Neptune. HST has revealed exciting images of
and Neptune while their quantitative analysis has been slow due to limitations
in available filters. Our short, spatially-resolved spectroscopic program will
reveal accurate spectral shapes across each WFPC2 filter which then will
improve the reliability of interpretations based on hundreds of past and future
WFPC2 images. Similarly, WFPC2 images of Titan required the addition of STIS
spectra before the latest improvements in our understanding of its atmosphere
were possible.

GO 9172

Molecular Hydrogen in the Damped LyAlpha Absorber of Q1331+170

We wish to search for the Lyman and Werner absorption lines of molecular
hydrogen {rest LambdaLambda = 1104 to 911 Angstrom} associated with the
well-studied damped LyAlpha and 21-cm absorber at z=1.776 in Q1331+170. The
detection of C I absorption in this system make this a promising candidate
for a
search. After detecting H_2, we plan to measure the relative population in the
individual rotation states. The J = 0, 1, 2, 3 states will yield the kinetic
temperature of the gas, while the weak J = 4 and higher states will measure {or
limit} the local UV radiation field and hydrogen density. The detection of
C I^*
has been used to measure the cosmic microwave background temperature at
and test the validity of the Big Bang model. The observed population of the
structure levels of C I can be explained entirely by the expected CMB
with surprisingly strong limits on local sources of excitation. The H_2
will enable us to check this result, by allowing us to make an independent
estimate of the rate of UV and collisional pumping of the C I^* levels.


Pure Parallel Imaging Program: Cycle 10.

program for STIS during cycle 10.


Dark current, shading profile, and read noise monitoring program

for all three NICMOS cameras from the onset of normal NCS operations throughout
the start of Cycle 11.



The goal is to obtain ACCUM darks with exposure time=256 seconds with
taken away from the SAA. These are needed to calibrate the post-SAA darks that
will be used to remove CR persistence from NICMOS science images. In the early
Cycle 11 calibration plan they should be obtained every 4 weeks. We will
evaluate need for repeats later


NICMOS Cycle 10 Early Calibration Monitor

This calibration program is the early Cycle 10 NICMOS monthly monitor
program. A
series of flat field observations will be obtain to monitor the stability and
health of the NICMOS detectors.

ACS 9480

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
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 ideal. ACS/WFPC2 9481 Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS Survey Fields In anticipation of the allocation of ACS high-latitude imaging survey{s}, we request a modification of the default pure parallel program for those WFPC2 parallels that fall within the ACS survey field. Rather than duplicate the red bands which will be done much better with ACS, we propose to observe in the near-ultraviolet F300W filter. These data will enable study of the rest-frame ultraviolet morphology of galaxies at 0

SpaceRef staff editor.