Status Report

NASA Hubble Space Telescope Daily Report # 3500

By SpaceRef Editor
December 3, 2003
Filed under , ,






MAMA Sensitivity and Focus Monitor Cycle 12

Monitor sensitivity of each MAMA grating mode to detect any change due to
contamination or other causes. Also monitor the STIS focus in a spectroscopic
and an imaging mode.

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
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.


CCD Daily Monitor

This program consists of basic tests to monitor, the read noise, the
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 10046

CCD Hot Pixel Annealing

Hot pixel annealing will be performed once every 4 weeks. The CCD TECs will be
turned off and heaters will be activated to bring the detector temperatures to
about +20C. This state will be held for approximately 12 hours, after which the
heaters are turned off, the TECs turned on, and the CCDs returned to normal
operating condition. To assess the effectiveness of this procedure, a bias and
two dark images will be taken after the annealing procedure for both WFC and
HRC. The HRC darks are taken in parallel with the WFC darks.

ACS/WFC 9744

HST Imaging of Gravitational Lenses

Gravitational lenses offer unique opportunities to study cosmology, dark
galactic structure, galaxy evolution and quasar host galaxies. They are
also the
only sample of galaxies selected based on their mass rather than their
luminosity or surface brightness. While gravitational lenses can be discovered
with ground-based optical and radio observations, converting them into
astrophysical tools requires HST. HST has demonstrated that it is the only
telescope that can in each case precisely locate the lens galaxy, measure its
luminosity, color and structure, and search for lensed images of the source
galaxy given the typical image separations of ~1”. We will obtain ACS/WFC
V and
I images and NICMOS H images of 21 new lenses never observed by HST and
images of 16 lenses never observed by HST in the IR. As in previous cycles, we
request that the data be made public immediately.

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
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

NIC1/NIC2/NIC3 9995

Photometric Stability

This NICMOS calibration proposal carries out photometric monitoring
during Cycle 12. The format of the program is identical to that of the Cycle 11
program 9639, except that the frequency has been reduced to bimonthly.

NIC2 9726

A NICMOS search for obscured supernovae in starburst galaxies

Recent near-IR monitoring campaigns were successful in detecting obscured
supernovae {SNe} in starburst galaxies. The inferred SN rate is much higher
that obtained in previous optical campaigns, but it is still significantly
than expected by the high level star formation of these systems. One possible
explanation for the shortage of SNe is that most of them occur in the nuclear
region, where the limited angular resolution of groundbased observations
prevents their detection. We propose NICMOS SNAP observations of a sample of
starburst galaxies already observed once by NICMOS, with the goal of exploiting
its sensitivity and angular resolution to detect nuclear obscured SNe which
might have been missed by groundbased surveys. These observation will allow to
assess the real SN rate in starbust galaxies and deliver a sample of SN
occurring in the extreme environment of galactic nuclei. We expect to detect
more than 55 SNe {if the whole sample is observed}. If the number of SNe
detected in the program is much lower than expected it would prompt for a
revision of our understanding of the relation between the star formation rate
and the SN rate.

NIC2 9834

Finding Planets in the Stellar Graveyard: A Faint Companion Search of White
Dwarfs with NICMOS

We propose to do a deep search for substellar objects in orbit around white
dwarfs with the newly refurbished NICMOS camera as part of the PI’s doctoral
thesis work. Direct imaging of planets around main sequence stars is difficult
due to the large contrast ratio, a problem which is much less severe for
companions to white dwarfs. White dwarfs are not usually considered in planet
searches but recent theoretical work and observations are motivating new
searches for planetary systems and dust disks around DAZ white dwarfs. We
propose to conduct the search with the NIC2 coronagraph to find resolved
companions and do photometry to search for unresolved companions through
excesses. We estimate that the survey will be sensitive to brown dwarfs, high
mass jovian planets, and dust disks. By probing a wide range of orbital
separations and companion masses, this survey will help to answer questions
about the brown dwarf desert, common envelope evolution, and planet formation.
HST and NICMOS provide a unique capability to do this search, as no ground
observatory with AO can adequately search for faint companions as close and
such high contrast.

NIC2 9856

A near-IR imaging survey of submm galaxies with spectroscopic redshifts

Submillimeter {submm} surveys with SCUBA have identified a population of
obscured star-forming and active galaxies at high redshift. Our recent
spectroscopic campaigns with the Keck-10m telescope have uncovered
redshifts for
37 SCUBA galaxies. The wide redshift range of the radio identified submm
population {z=1-4} implies that many varieties of sources driven by different
physical processes may be selected in a submm survey. Only HST observations
the resolution to detect any changes in the morphologies of SCUBA galaxies with
increasing cosmic time. We propose to use HST-NICMOS, ACS to obtain 2-filter
images of a sample of 15 SCUBA galaxies with redshifts spanning z=0.8-3.5. Our
goal is to understand what physical process {major mergers?} drive their strong
evolution and great luminosities, and what the implications are for galaxy
evolution models.


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.


Externally Illuminated Circumstellar Material in the Young Nebulous Cluster NGC

HST imaging of the Orion M42 H II region has revealed circumstellar
emission and
absorption regions {“proplyds”} with sizes comparable to those expected for
protoplanetary disks. Disk morphology is directly observed in a dozen cases;
disk photoevaporation is now the working model to explain the ionized rims seen
at more than 100 Trapezium cluster stars. Are the Trapezium circumstances
unique? Different cluster ages, densities, and UV radiation fields may strongly
affect proplyd characteristics. To address these questions, we have
searched for
proplyds in several other young nebulous clusters, and found that the embedded
infrared cluster associated with the NGC 2024 H II region has a large group of
strong proplyd candidates. Our WFPC2 images of the optically visible edge
of the
cluster have identified an HAlpha proplyd aligned toward a B0 star. Our VLA 3.6
cm maps show compact ionization regions coincident with 20 members of the
infrared cluster – a result similar to the original VLA proplyd discovery
in M42
by Churchwell {1987}. These results strongly indicate that infrared emission
line imaging of selected cluster members should reveal many objects similar to
the those in M42. We propose NIC2 Paschen Alpha and continuum imaging of
fourteen of the NGC 2024 compact VLA sources. Our goal is to resolve and
characterize their circumstellar structures, and compare them with those
seen in

STIS 9435

Systematic Search for Rotation at the Base of Outflows from T Tauri Stars

We wish to search for rotation signatures in the initial portion {first 100 AU}
of a sample of outflows emanating from T Tauri stars {TTSs}. This project
originates from our detection of systematic transverse radial velocity
shifts in
STIS spectra of the DG Tau jet {Bacciotti et al., 2002}. The shifts,
observed in
a region where the flow is already collimated, but has not yet manifestly
interacted with its environment, are consistent with the predictions of
centrifugal launching models, and may constitute the first observed indication
for rotation in the initial portion of a jet flow. Rotation is a fundamental
ingredient in star formation theories, thus we propose to confirm the above
result by carrying out a systematic survey in similar flows. We plan to
take for
each jet a STIS spectrum in the 6300 — 6800 Angstrom range, with the slit
perpendicular to the flow direction and at a distance of about 0.”3 from the
source {i.e., in our targets, 40 — 70 AU along the jet depending on
angle}. Since the flows are resolved transversely with HST, the proposed slit
orientation allows for the direct detection of systematic velocity shifts.
found, we will check for consistency between the sense of rotation observed and
that of the underlying disk through CO interferometric measurements. As a
by-product, estimates of the excitation conditions across the flow {including
ionization fraction} and of the mass outflow rates will be derived.

STIS/CCD 10000

STIS Pure Parallel Imaging Program: Cycle 12

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

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


Rotation in Jets from Young Stars: investigating NUV lines with very high
Spectral Resolution

Optical STIS spectra of the jets from DG Tau, RW Aur, TH 28 and LkHa 231
obtained by us {prop IDs. 7311, 9435} show systematic transverse radial
shifts in the region where the flow has just been accelerated and collimated
{Bacciotti et al, 2002}, i.e. within about 100 AU from the source. We interpret
such shifts as evidence for jet rotation. Whether YSO jets rotate is a
fundamental question in star formation because it has been suggested that jets
might be the way excess angular momentum is removed from the star/disk system,
thereby allowing the star to accrete. In particular it is important to know if
observed toroidal velocities are in agreement with predictions of
magneto-centrifugal jet launching models. The limited spatial and spectral
resolution of STIS in the optical however, only allows one to say qualitatively
that the observed rotational velocities are in rough agreement with theory.
Moreover only the resolved peripheral regions of the flow can be studied.
We are
proposing here to exploit the higher spatial and spectral resolution of STIS in
the NUV to measure transverse jet velocity profiles.This is a task which can
only be undertaken by the HST and which is ideally suited to the STIS. To
measure the velocity profiles, we will observe the Mg II doublet at 2800
Angstrom {using the E230M echelle and the 6 X 0.2 slit transverse to the flow}.
In comparison to the optical, the NUV affords us double the spatial resolution
and we will be able to detect velocity differences across the jet down to 2
km/s. Not only should we be able to determine for the first time the detailed
rotational velocity profile across a jet but we also expect to spatially
the high velocity axial core of the jet in the NUV. Finally we add that as very
few NUV observations of the initial jet beam of YSO jets are available, our
datasets should be a valuable contribution to the HST archive.

STIS/MA1 10034

Cycle 12 MAMA Dark Monitor

This test performs the routine monitoring of the MAMA detector dark noise. This
proposal will provide the primary means of checking on health of the MAMA
detectors systems through frequent monitoring of the background count rate. The
purpose is to look for evidence of change in dark indicative of detector

WFPC2 10068

WFPC2 CYCLE 12 Standard Darks

This dark calibration program obtains dark frames every week in order to
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
will also provide a monitor of radiation damage to the CCDs.

WFPC2 10069

WFPC2 CYCLE 12 Supplemental Darks, Part 1/3

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

WFPC2 10072


This calibration proposal is the Cycle 12 routine internal monitor for
WFPC2, to
be run weekly to monitor the health of the cameras. A variety of internal
exposures are obtained in order to provide a monitor of the integrity of
the CCD
camera electronics in both bays {gain 7 and gain 15}, a test for quantum
efficiency in the CCDs, and a monitor for possible buildup of contaminants on
the CCD windows.

WFPC2 10073

Earth Flats

This proposal monitors flatfield stability. This proposal obtains sequences of
Earth streak flats to construct high quality flat fields for the WFPC2 filter
set. These flat fields will allow mapping of the OTA illumination pattern and
will be used in conjunction with previous internal and external flats to
new pipeline superflats. These Earth flats will complement the Earth flat data
obtained during cycles 4-11.

WFPC2 10082

POMS Test Proposal: WFII backup parallel archive proposal

This is a POMS test proposal designed to simulate scientific plans

WFPC2 9709

POMS Test Proposal: 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 9968

Fundamental properties of L-type dwarfs in binaries

We propose to characterize the physical properties of eight L-dwarfs in four
binary systems. Our goal is to obtain astrometric, photometric and
measurements of each component that will yield basic information on their
atmospheric and dynamical properties. The high angular resolution of HST is
essential because all these systems have angular separations $le$0.5 arcsec.
They do not have bright enough stars nearby that can be used for natural guide
adaptive optics in ground-based telescopes. In Cycles~10 and 11 we propose to
obtain WFPC2 and STIS data, allowing the determination of parallax, proper
motion, position and spectral type for each component. In Cycle 12 we plan to
obtain additional WFPC2 images for follow-up of the orbital motion and
refinement of parallax and proper motion. We will also monitor possible
intrinsic photometric variability in two filters {F675W and F814W}. The STIS
observations will provide spectral types, gravity sensitive indicators, and
chromospheric activity {H$_ lpha$ emission} for each component. These 4 systems
will constitute benchmarks for determining dynamical masses of L dwarfs, and
inferring the age-mass-spectral type relationship of this new spectral class.


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


1176-0 – HST486 Software Memory Dump – RAM @ 335/2210z and 336/0608z

                         SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq             12                       12
FGS REacq             6                          6
FHST Update           23                        23


SpaceRef staff editor.