Status Report

NASA Hubble Space Telescope Daily Report # 3569

By SpaceRef Editor
March 15, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science




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.

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

FGS 9879

An Astrometric Calibration of the Cepheid Period-Luminosity Relation

We propose to measure the parallaxes of 10 Galactic Cepheid variables.
There is no other instrument on or off the earth that can consistently
deliver HST FGS level of precision for critical parallaxes. When these
parallaxes {with 1-sigma precisions of 10% or better} are added to our
recent HST FGS parallax determination of delta Cep {Benedict et al
2002}, we anticipate determining the Period-Luminosity relation zero
point with a 0.03 mag precision. In addition to permitting the test of
assumptions that enter into other Cepheid distance determination
techniques, this calibration will reintroduce Galactic Cepheids as a
fundamental step in the extragalactic distance scale ladder. A
Period-Luminosity relation derived from solar metallicity Cepheids can
be applied directly to extragalactic solar metallicity Cepheids,
removing the need to bridge with the Large Magellanic Cloud and its
associated metallicity complications.


Timing of the proposed optical counterpart of the 16 ms LMC X-ray
pulsar PSR J0537-6910

PSR J0537-6910 is a fast, young {~ 5, 000 yrs} X-ray pulsar -still
undetected in radio- at the the center of the SNR N157B in the LMC.
PSR J0537-6910 is a champion pulsar – with a period of 16 ms it is the
fastest rotator among ordinary pulsars, with the sharpest X-ray pulse
among young pulsars. It is the most energetic one {together with the
Crab}, with a rotational energy loss log{dE/dt} ~ 38.7 erg/s, and its
space velocity {> 1, 000 km/s}, inferred from the shape of its X-ray
bow-shock nebula, is probably one of the highest in the pulsar family.
Taking advantage of the refined Chandra position of the X-ray pulsar,
we have recently performed multi-band high-resolution imaging with the
ACS {GO 9471} and we found a potential counterpart, characterized by
unusual colours. Here, we propose to observe the candidate counterpart
with the STIS/NUV-MAMA in its TIME-TAG mode to search for pulsations
at the X-ray period, which would unambiguously confirm the proposed

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.


A SNAPSHOT Survey of Sharp-Lined Early B-Type Stars

Although spectrum synthesis studies of the UV spectra of sharp-lined
main sequence B stars provide us with some our best determinations of
the abundances of the Fe group and neutron capture elements and the
chemical evolution in our galaxy and the Magellanic Clouds, the HST
archive is virtually devoid of high resolution spectra of the bright
nearby B stars that have become to be regarded as abundance standards.
For example, there are NO observations of HR 1886, iota Her, and tau
Her, the sharpest-lined representatives {V sin i < 5 km/s} of spectral
classes B1 V, B3 IV-V and B5 IV, and only a few tiny spectral
intervals of gamma Peg {B2 IV}. Information on the abundances of the
Fe group is important for computing opacities for stellar evolution
calculations and for determining astrophysical f-values. There are no
suitable galactic standards in the HST database to compare with recent
HST/STIS observations of B stars in the Magellanic Clouds and the
likely future observations of similar objects in M31 and other nearby
galaxies. To correct this deficiency, we propose SNAPSHOT observations
with the STIS E140M and E230M gratings of 33 of the best bright
abundance standards in nearby clusters and the galactic field. Using
this data we will determine the abundances of the Fe group and heavy
elements using the technique of spectrum synthesis with LTE and NLTE
treatments. We waive the proprietary period.


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

STIS 9786

The Next Generation Spectral Library

We propose to continue the Cycle 10 snapshot program to produce a Next
Generation Spectral Library of 600 stars for use in modeling the
integrated light of galaxies and clusters. This program is using the
low dispersion UV and optical gratings of STIS. The library will be
roughly equally divided among four metallicities, very low {[Fe/H] lt
-1.5}, low {[Fe/H] -1.5 to -0.5}, near-solar {[Fe/H] -0.3 to 0.1}, and
super-solar {[Fe/H] gt 0.2}, well-sampling the entire HR-diagram in
each bin. Such a library will surpass all extant compilations and have
lasting archival value, well into the Next Generation Space Telescope
era. Because of the universal utility and community-broad nature of
this venture, we waive the entire proprietary period.


Confirmation of New Candidates for the Study of Intergalactic Helium

The reionization of intergalactic helium is believed to take place
between redshift 3 and 4. The study of HeII Lyman-alpha absorption in
four quasars at 2.7<z<3.3 demonstrates the great potential of such an
intergalactic-medium {IGM} probe and suggests that the reionization
epoch is at higher redshifts. Clean quasar sightlines may be found
only from massive pre-selection processes in the optical and UV,
because of random, severe absorption by intervening Lyman-limit
systems. The SDSS has discovered approximately 36000 quasars, and we
propose to verify the UV detectability in 70 top candidates for helium
studies extending to even higher redshift. Our proposed approach has
already proven successful, and additional positive confirmations will
allow follow-up observations, with STIS or COS, to pinpoint the epoch
of reionization of the IGM, and the evolution of its properties near
that period.


Morphologies of EROs and Field Galaxies in SIRTF’s First Look Survey:
A Rich Early Release Dataset

The SIRTF First Look Survey {FLS} will be the first scientific program
undertaken with NASA’s next Great Observatory. The FLS provides the
first large sample of dusty galaxies to redshifts to z < 2 and a
census of large-scale global IR properties {luminosities, color
temperatures, total dust mass, etc.} HST observations to measure
morphology are critical to provide insight into the mechanisms which
build up the various galaxy components–disks, bulges as well as
chaotic morphologies. We will measure quantitative morphology of fifty
extremely red objects {EROs} with targeted NICMOS pointings and
hundreds of field galaxies with ACS in parallel in the FLS. We aim to
understand how EROs fit into the evolutionary sequence of galaxy
formation. The combined HST and SIRTF observations will provide clues
into the physical processes responsible for generating powerful far-IR
sources or, conversely, may explain why some galaxies are inactive in
the far-IR. Ancillary ground-based optical, near-IR, and radio data
have already been obtained and DEIMOS spectra are scheduled for June,
2003. We waive the proprietary period for the HST observations and if
executed early in Cycle 12 the FLS will be the first complete
SIRTF+HST survey made available to the astronomical community, well in
advance of the majority of the Legacy observations and all of the GTO


Towards a global understanding of accretion physics – Clues from an UV
spectroscopic survey of cataclysmic variables

Accretion inflows and outflows are fundamental phenomena in a wide
variety of astrophysical environments, such as Young Stellar Objects,
galactic binaries, and AGN. Observationally, cataclysmic variables
{CVs} are particularly well suited for the study of accretion
processes. We are currently carrying out a Cycle 11 STIS UV
spectroscopic snapshot survey of CVs to fully exploit the diagnostic
potential of these objects for our understanding of accretion physics.
While the data obtained so far are of excellent quality, the number of
targets that will be observed in Cycle 11 is too small for a
statistically significant analysis {only 19 objects out of our 149
accepted Cycle 11 snapshot targets have been observed at the time of
writing}. We propose here to extend this survey into Cycle 12,
building a homogenous database of accretion disc and wind outflow
spectra covering a wide range of mass transfer rates and binary
inclinations. We will analyze these spectra with state-of-the-art
accretion disc model spectra {SYNDISK}, testing our current knowledge
of the accretion disc structure, and, thereby, providing new insight
into the so far not well understood process of viscous dissipation. We
will use our parameterised wind model PYTHON for the analysis of the
radiation driven accretion disc wind spectra, assessing the
fundamental question whether the mass loss rate correlates with the
disc luminosity. In addition, our survey data will identify a number
of systems in which the white dwarf significantly contributes to the
UV flux, permitting an analysis of the impact of mass accretion on the
evolution of these compact stars. This survey will triple the number
of currently available high-quality accretion disc / wind outflow /
accreting white dwarf spectra, and we waive our proprietary rights to
permit a timely use of this database.

ACS/WFC 9575

Default {Archival} Pure Parallel Program.

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

ACS/WFPC2 9488

Cosmic Shear – with ACS Pure Parallel Observations

The ACS, with greater sensitivity and sky coverage, will extend our
ability to measure the weak gravitational lensing of galaxy images
caused by the large scale distribution of dark matter. We propose to
use the ACS in pure parallel {non- proprietary} mode, following the
guidelines of the ACS Default Pure Parallel Program. Using the HST
Medium Deep Survey WFPC2 database we have measured cosmic shear at
arc-min angular scales. The MDS image parameters, in particular the
galaxy orientations and axis ratios, are such that any residual
corrections due to errors in the PSF or jitter are much smaller than
the measured signal. This situation is in stark contrast with
ground-based observations. We have also developed a statistical
analysis procedure to derive unbiased estimates of cosmic shear from a
large number of fields, each of which has a very small number of
galaxies. We have therefore set the stage for measurements with the
ACS at fainter apparent magnitudes and smaller, 10 arc-second scales
corresponding to larger cosmological distances. We will adapt existing
MDS WFPC2 maximum likelihood galaxy image analysis algorithms to work
with the ACS. The analysis would also yield an online database similar
to that in


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.


First Spectroscopy of an Asteroid and its Satellite: {45} Eugenia and
S/1998 {45} 1

We recently made the first-ever discovery of a satellite of an
asteroid from the Earth, using adaptive optics {Merline et al. 1999a,
1999b}. We propose here to acquire the first separate, comparative,
and simultaneous spectra of an asteroid and its satellite. We will
employ the UV-capabilities and high-spatial-resolution properties of
STIS to study {45}Eugenia, and its satellite, S/1998{45}1, by
obtaining medium-resolution spectra over the range 2900-10300
Angstrom, using only two grating settings, on a single HST orbit. We
will determine whether the spectra, and hence surface compositions,
are similar or different in a parent-satellite pair, and to test
hypotheses concerning satellite production mechanisms. From the
orbital parameters, determined using our ground-based adaptive-optics
images, we have already determined that {45}Eugenia has a surprisingly
low density of 1.2 g cm^-3. We know the spectrum of Eugenia is a
{Tholen} FC-type, which is similar to the common C-types, but differs
by the lack of a UV-band or UV-dropoff and by subtle, but measurable
differences in the spectral slope. Both the UV-region and the
existence of subtle absorption features in the near-IR {~ 0.9 micron}
are diagnostic of the specific differences between F-, C-, and {Bus’}
X-class. HST spectroscopy is the only way to separate the pair,
because ground-based adaptive optics is not available in the UV and
cannot yet provide adequate resolution in the visible.

STIS/CCD 10085

STIS Pure Parallel Imaging Program: Cycle 12

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

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 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


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.

STIS/CCD 10030

STIS/CCD Spectroscopic Sensitivity Monitor for Cycle 12

Monitor sensitivity of each CCD grating mode to detect any change due
to contamination or other causes.

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 10017

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD.


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

HSTAR 9350: GS Acquisition (2,1,2) @ 072/15:22:45Z ended in FL backup
on FGS 1 due to QF2STOPF. Prior FHST FM updates both had low errors.
Under investigation.


1208-0 Adjust ACS Error Count Limit @ 073/0619z
1208-1 Adjust ACS Error Count Limit @ 074/0747z
0916-0 Tabulation of Slew Attitude Error (Miss-distance) @ 075/0827z

                           SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq               33                        33
FGS REacq               11                        11
FHST Update             52                        52


Executed first commands from CCS SUN "F" String to the HST Observatory
@ 072/18:36Z. All 486 and NSSC-1 loads were uplinked from CCS "A".
Command transferred from CCS "F" to CCS "D" @ 074/03:50Z, transferred
command to CCS "F" @ 075/08:40Z.

Test events have been scheduled to verify CCS "H" String, CCS Release capability to successfully support GCMR/ODM traffic.

SpaceRef staff editor.