Status Report

NASA Hubble Space Telescope Daily Report #3925

By SpaceRef Editor
August 17, 2005
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT       # 3925

PERIOD COVERED: UT August 16, 2005 (DOY 228)


ACS/HRC 10431

A Search for Faint Companions of Altair

We propose to use the innovative new technique of spectral
deconvolution {Sparks & Ford 2002} to search for very faint
companions, possibly extrasolar planets shining by reflected light,
around Altair, the nearest bright, single star to the Sun. The
technique offers a Poisson-limited detection capability that brings
Jovian-class planets into the realm of feasibility for a select few
stars. We turn the wavelength dependence of the coronagraphic PSF to
advantage and use it to eliminate stray light from the host star. As
part of the detection process, we obtain a spectrum over the
wavelength range, 750 nm to 1 micron, with 9% resolution. The search
will be orders of magnitude more sensitive than all previous efforts
and should take us to within about an order of magnitude of the Jovian
luminosity flux limit.

ACS/HRC 10525

Characterizing the Near-UV Environment of M Dwarfs: Implications for
Extrasolar Planetary Searches and Astrobiology

We propose SNAP observations with the ACS HRC PR200L prism, designed
to measure the near ultraviolet emission in a sample of 107 nearby M
dwarfs. The sample spans the mass range from 0.1 – 0.6 solar masses
{temperature range 2200K – 4000K} where the UV energy distributions
vary widely between active and inactive stars. The strength and
distribution of this UV emission can have critical consequences for
the atmospheres of attendant planets. Our proposed observations will
provide desperately needed constraints on models of the habitability
zone and the atmospheres of possible terrestrial planets orbiting M
dwarf hosts, and will be used to sharpen TPF target selection. In
addition, the NUV data will be used in conjunction with existing
optical, FUV and X-ray data to constrain a new generation of M dwarf
atmospheric models, and to explore unanswered questions regarding the
dynamo generation and magnetic heating in these low-mass stars.

ACS/HRC/NIC3 10182

Towards a Comprehensive Understanding of Type Ia Supernovae: The
Necessity of UV Observations

Type Ia supernovae {SNe Ia} are very important to many diverse areas
of astrophysics, from the chemical evolution of galaxies to
observational cosmology which led to the discovery of dark energy and
the accelerating Universe. However, the utility of SNe Ia as
cosmological probes depends on the degree of our understanding of SN
Ia physics, and various systematic effects such as cosmic chemical
evolution. At present, the progenitors of SNe Ia and the exact
explosion mechanisms are still poorly understood, as are evolutionary
effects on SN Ia peak luminosities. Since early-time UV spectra and
light curves of nearby SNe Ia can directly address these questions, we
propose an approach consisting of two observational components: {1}
Detailed studies of two very bright, young, nearby SNe Ia with HST UV
spectroscopy at 13 epochs within the first 1.5 months after discovery;
and {2} studies of correlations with luminosity for five somewhat more
distant Hubble-flow SNe Ia, for which relative luminosities can be
determined with precision, using 8 epochs of HST UV spectroscopy
and/or broad-band imaging. The HST data, along with extensive
ground-based optical to near-IR observations, will be analyzed with
state-of-the-art models to probe SN Ia explosion physics and constrain
the nature of the progenitors. The results will form the basis for the
next phase of precision cosmology measurements using SNe Ia, allowing
us to more fully capitalize on the substantial past {and future}
investments of time made with HST in observations of high-redshift SNe

ACS/WFC 10626

A Snapshot Survey of Brightest Cluster Galaxies and Strong Lensing to
z = 0.9

We propose an ACS/WFC snapshot survey of the cores of 150 rich galaxy
clusters at 0.3 < z < 0.9 from the Red Sequence Cluster Survey {RCS}. An examination of the galaxian light in the brightest cluster galaxies, coupled with a statistical analysis of the strong-lensing properties of the sample, will allow us to contrain the evolution of both the baryonic and dark mass in cluster cores, over an unprecedented redshift range and sample size. In detail, we will use the high- resolution ACS images to measure the metric {10 kpc/h} luminosity and morphological disturbances around the brightest clusters galaxies, in order to calibrate their accretion history in comparison to recent detailed simulations of structure formation in cluster cores. These images will also yield a well-defined sample of arcs formed by strong lensing by these clusters; the frequency and detailed distribution {size, multiplicity, redshifts} of these strong lens systems sets strong constraints on the total mass content {and its structure} in the centers of the clusters. These data will also be invaluable in the study of the morphological evolution and properties of cluster galaxies over a significant redshift range. These analyses will be supported by extensive ongoing optical and near-infrared imaging, and optical spectroscopy at Magellan, VLT and Gemini telescopes, as well as host of smaller facilities.

ACS/WFC/NIC3 10405

Probing the establishment of galaxy morphologies in the best-studied
high-redshift structure

We propose deep ACS I-band imaging of arguably the best-studied
high-redshift proto-cluster environment, a high-contrast structure in
the SSA22 field at z=3.1. Our on-going study of this region has
identified over 400 probable members of this structure across a
16-arcmin-square field, selected through narrow-band Lyman-alpha
emission, Lyman-break photometric criteria and far-infrared/radio
emission. Our proposed high-resolution imaging of galaxies in the
z=3.1 structure and in the nearby field, will provide morphological
information on galaxies over nearly two-orders of magnitude in local
density at this early epoch. This will allow us for the first time to
test whether galaxy morphology is defined at the formation of a galaxy
or reflects processes acting on it during its lifetime.

FGS 10386

Long Term Monitoring of FGS1r in Position Mode

It is known from our experience with FGS3, and later with FGS1r, that
an FGS on orbit experiences long term evolution, presumably due to
disorption of water from the instrument’s graphite epoxy composits.
This manifests principly as a change in the plate scale and
secondarily as a change in the geometric distortions. These effects
are well modeled by adjustments to the rhoA and kA parameters which
are used to transform the star selector servo angles into FGS {x, y}
detector space coordinates. By observing the relative positions of
selected stars in a standard cluster at a fixed telescope pointing and
orientation, the evolution of rhoA and kA can be monitored and
calibrated to preserve the astrometric performance of FGS1r.

NIC1/NIC2/NIC3 10721

NICMOS dark current tests for newly implemented SPARS sequences

On June 12, 2005, 4 new NICMOS multiaccum sequences {SPARS4, SPARS16,
SPARS32, SPARS128} were implemented. The purpose of this observation
is to measure the dark currents for these new multiaccum sequences for
all three NICMOS detectors.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration – CR Persistence Part 4

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.

NIC2 10176

Coronagraphic Survey for Giant Planets Around Nearby Young Stars

A systematic imaging search for extra-solar Jovian planets is now
possible thanks to recent progress in identifying “young stars near
Earth”. For most of the proposed young {<~ 30 Myrs} and nearby {<~ 60 pc} targets, we can detect a few Jupiter-mass planets as close as a few tens of AUs from the primary stars. This represents the first time that potential analogs of our solar system - that is planetary systems with giant planets having semi-major axes comparable to those of the four giant planets of the Solar System - come within the grasp of existing instrumentation. Our proposed targets have not been observed for planets with the Hubble Space Telescope previously. Considering the very successful earlier NICMOS observations of low mass brown dwarfs and planetary disks among members of the TW Hydrae Association, a fair fraction of our targets should also turn out to posses low mass brown dwarfs, giant planets, or dusty planetary disks because our targets are similar to {or even better than} the TW Hydrae stars in terms of youth and proximity to Earth. Should HST time be awarded and planetary mass candidates be found, proper motion follow-up of candidate planets will be done with ground-based AOs.

S/C ACS/HRC 10719

A Coordinated NICMOS and XMM Experiment to Observe the Variability of
Sgr A*

The massive black hole Sgr A* at the Galactic center has recently
shown not only quiescent emission at near-IR wavelengths, but also
flare activity with quasi-periodicity of 17 minutes. Our research
group has been granted two blocks of observing time with XMM-Newton to
monitor the spectral and temporal properties of Sgr A*. Simultaneously
with these X-ray observations, we will also monitor Sgr A* at radio,
submillimeter, near-IR, and gamma-ray wavelengths. We propose to use
NICMOS in parallel with the XMM observations to provide evidence of a
well- defined minimum periodicity in the spectrum of flare
periodicities. This, combined with periodicity in the near-IR line
emission, would strengthen the claim that the emitting gas resides at
the innermost stable circular orbit around the GC black hole, thus
measuring the spin parameter of a massive black hole. Current
groundbased near-IR data suggest a spin parameter of ~0.5. In
addition, the correlation pattern of emission over a wide spectrum
would elucidate a key issue of how to explain the low luminosity of
Sgr A*. The NICMOS on HST is the only instrument that can accurately
measure the 17 minute quasi-periodic variability of Sgr A* because of
the long time baseline over which HST can observe Sgr A* in parallel
with XMM-Newton.

WFPC2 10360


This calibration proposal is the Cycle 13 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.


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


9917 – OBAD Failed During Lunar Observation @228/2300z OBADS failed at
228/23:00 during OR#17498-0 Lunar Observation Viewing 1 OBAD 1.
Mnemonic QT2GMST showed MapFail.


17502-1 – Lunar Ob Viewing 1 Zero Observer @228/2245z

17498-0 – Lunar Observation Viewing 1 OBAD 1 @228/2302z

17506-0 – Lunar Observation Viewing 1 MAP 1 @229/0036z

17507-0 – Lunar Observation Viewing 1 MAP 2 @229/0212z

17508-1 – Lunar Observation Viewing 1 MAP 3 @229/0346z


                            SCHEDULED     SUCCESSFUL
FGS Gsacq                 06                      06
FGS Reacq                 06                      06
FHST Update              12                      12


Lunar Observation Map Summary: PCS evaluated data taken for gyro bias
update at 228/2054 and determined that the observer data used was
consistent with predictions, indicating that V2 attitude drift
resulting from the AOA would be small. Map data collected during the
visit indicated accumulating errors were consistent with estimates
based on maneuver angles and gyro bias errors

The Lunar Observations were transmitted to the Science Institute and
evaluated @229/0500z , with final analysis still in progress.

SpaceRef staff editor.