Status Report

NASA Hubble Space Telescope Daily Report #3630

By SpaceRef Editor
June 14, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




ACS 9760

ACS Imaging of the Gemini Deep Deep Survey Fields: Galaxy Assembly at
z = 1.5

We are presently carrying out the deepest redshift survey ever
undertaken {the Gemini Deep Deep Survey}. Spectra of extraordinary
quality have been taken in order to obtain redshifts in the so-called
"redshift desert" at 1<z<2. This redshift range corresponds to the
epoch of peak galaxy formation. In this proposal we request 40 orbits
of ACS imaging to determine the morphologies of 100-120 candidate
early-type galaxies with known redshifts in our survey fields. We seek
to determine if these systems are indeed elliptical galaxies and to
link their morphological states to their spectroscopically determined
ages, recent star-formation histories, and to the evolving global
stellar mass function at the peak epoch of galaxy assembly.


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 10002

Detailed Study of X-ray Jets from a Complete Survey

We propose deep followup HST and Chandra observations of two X-ray
jets, which are the X-ray brightest discovered in our Chandra survey
of quasars with known radio jets. With these data, we will compare
their X-ray, optical and radio morphologies. We will also obtain X-ray
and optical spectral indices, and spatially resolved SEDs from the
radio through the X-rays. This will allow us to determine the X-ray
emission mechanism at each point in these jets, and test critical
predictions made by each mechanism. We will also be able to track any
changes in physical conditions {including magnetic field and bulk
Lorentz factor} that are present in the observed 90 degree bends.

ACS/WFC 9765

The Dusty ISM Substructure in Nearby Spiral Galaxies

We propose an ACS V&I imaging snapshot survey of all nearby edge-on
spiral galaxies in order to measure the small scale structures in
their dust extinction down to the 10pc scale. Dust and molecular gas
are tightly coupled and therefore HST high resolution reddening maps
can reveal information about the cold ISM phase on a scale
inaccessible from the groundby any other means. We have recently
discovered a sudden change in dust lane properties using ground-based
data; all galaxies with rotation speeds in access of 120km/s show dust
lanes, but none of the slower rotators does. This transition may be
caused by a sudden change in the state of the multiphase ISM, and HST
resolution imaging is needed to fully quantify this effect. Analysis
will consist of full radiative transfer modeling of dust extinction
with realistic, fractal like substructure and power spectrum analysis
of the structure from the global to the 10pc scale. By observing a
sample of galaxies with a range in structural parameters we can
quantify how the cold ISM structure changes as function of radius,
rotation speed, local surface density, et cetera. This information is
duly needed with SIRTF soon providing a wealth of information on dust
absorption, but lacking the resolution to determine the small scale
distribution of the dust.

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.

NIC1/NIC2/NIC3 8792

NICMOS Post-SAA calibration – CR Persistence Part 3

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.

NIC3 9998

NICMOS Cycle 12 Grism Calibration and Standard Stars to 2.5microns

This is the grism calibration proposal.

STIS/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS/CCD 10020

CCD Bias Monitor – Part 2

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 10023

STIS CCD Spectroscopic Flats C12

Obtain CCD flats on the STIS CCD in spectroscopic mode

STIS/CCD 10024

STIS CCD Imaging Flats C12

Investigate flat-field stability over a bimonthly period.


Physical Parameters of the Erupting Luminous Blue Variable NGC 2363-V1

In 1996, we reported the discovery of a bright variable star in the
giant extragalactic H , ii region NGC 2363. Subsequent photometry and
high quality HST/STIS spectroscopy of this star, NGC 2363-V1, revealed
that we are witnessing a significant event in the evolution of a
massive star, namely a major eruption of a Luminous Blue Variable
{LBV}. A quantitative analysis of the STIS datasets gathered in 1997
and 1999 allowed us to determine the luminosity, mass loss rate, wind
terminal velocity, surface temperature and even Fe content of this
erupting LBV. Because such events are rare, continuous monitoring of
the physical parameters of NGC 2363- V1 over the course of its present
eruption will provide an invaluable set of constraints for theoretical
models. We therefore propose to obtain high quality STIS spectra of
this star once a year for the next three observing Cycles.


Iron deficiency in hot hydrogen-deficient post-AGB stars

The first attempt to measure the iron abundance in hot
hydrogen-deficient post-AGB stars arrived at a surprising result. From
the non-detection of iron lines in FUSE spectra of three extremely hot
{Teff>100, 000K} PG1159-type central stars of the planetary nebulae,
we found that iron is deficient by at least one order of magnitude. We
propose HST/STIS observations of three hydrogen-deficient post-AGB
stars, each representing the UV-brightest member of a spectroscopic
subclass. High-resolution UV spectroscopy will reveal the origin of
the iron deficiency. The determination of the Fe/Ni abundance ratio
can decide if dust fractionation in the former AGB star atmosphere or
s-process neutron-capture in the interior helium-buffer layer is
responsible for the iron depletion. In the latter case we can verify
our understanding of the "born-again” star phenomenon and of the
s-process synthesis of trans-iron elements in low-mass AGB stars.

WFPC2 10071

WFPC2 CYCLE 12 Supplemental Darks Part 3/3

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


Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.) None

COMPLETED OPS REQs: 17195-0 – Set ACS Memory Monitor @ 161/1827z


                        SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq            6                             6
FGS REacq            9                             9
FHST Update         8                             8


SpaceRef staff editor.