Status Report

NASA Hubble Space Telescope Daily Report # 3804

By SpaceRef Editor
February 25, 2005
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HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT        # 3804 (Note: covers two days)



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.

FGS 10457

2-Gyro F2G Test Miscellaneous Orbits

This proposal is part of the February on-orbit 2-gyro testing.

ACS/HRC 10445

ACS Two-Gyro mode coronography test

This test of the coronagraphic procedure duplicates observations that
have been taken in normal 3-gyro mode in proposal . It will take place
in the period February 21st to 23rd 2005. The available roll angles
depend on the dates. Earth flats with the coronagraph in place are
taken every week as part of proposal 10377. The last observation taken
before entering 2-Gyro mode should ideally be 2 days before this
proposal starts. If the interval is shorter there will not be enough
time to generate the best offset but if it is longer there is a
greater chance for an intervening spot movement. One orbit is used to
measure the light which gets around the coronagraph in four filters.
The second orbit is a test of the repeatibility and the third orbit
replicates the others but at a different roll angle to permit a more
detailed analysis of the coronagraphic performance. We include two
pairs of HRC earth flats, immediately following the coronagraphic
observations, taken with the coronagraph in place to measure the exact
position of the spot, which sometimes moves several pixels. The
coronagraphic observations include a USE OFFSET incorporating the
information gained from the earth flats. Repeat 3-gyro measurements
and compare.


ACS & WFPC2 Two-gyro PSF, pointing and dither test

12 orbits High priority observations {5 orbits} will be observed
together at start of two- gyro SMS. Remaining 7 orbits provide further
tests and additional experience in two-gyro mode. Goals: PSF, PSF
repeatability, pointing and stability within the orbit {requirements
1a, 1c, 2 , 4}

ACS/HRC 10401

A Proper Motion Search for Intermediate Mass Black Holes in Globular

Establishing the presence or absence of intermediate-mass black holes
{IMBH} in globular clusters is crucial for understanding the evolution
of dense stellar systems. We propose a systematic search for IMBHs by
conducting an imaging/proper motion study of the centers of five of
the closest, most centrally concentrated Galactic globular clusters.
ACS/HRC observations allow for accurate proper motion measurements for
stars all the way into the center of each cluster. Our approach
consists of exploiting the blue/near-ultraviolet wavelength range in
each of cycles 13 and 14, in order to dim both the bright red giants
and the background of faint red stars, hence alleviating the crowding
problems experienced by previous studies. Both filter and target
selection are critical for the success of this project, and no
previous HST program has an appropriate combination to allow proper
motion measurements for most stars into the very centers of crowded
clusters. The velocity measurements will allow us to: {i} place
constraints on the mass of a central black hole in each cluster
{detailed calculations show that the proposed observations are
sufficient to detect any central black hole with a mass as low as 3000
solar masses at the greater than 3 sigma level}; {ii} derive the
internal velocity dispersion as a function of cluster radius; {iii}
verify or reject previous reports of cluster rotation; and {iv}
directly measure any velocity anisotropy as a function of radius.

ACS/HRC 10377

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L- flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronagraphic
monitoring is required to assess the changing position of the spots.

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.

WFPC2 10359

WFPC2 CYCLE 13 Standard Darks

This dark calibration program obtains 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.

ACS/WFC/NIC2 10189

PANS-Probing Acceleration Now with Supernovae

Type Ia supernovae {SNe Ia} provide the most direct evidence for an
accelerating Universe, a result widely attributed to dark energy.
Using HST in Cycle 11 we extended the Hubble diagram with 6 of the 7
highest-redshift SNe Ia known, all at z>1.25, providing conclusive
evidence of an earlier epoch of cosmic deceleration. The full sample
of 16 new SNe Ia match the cosmic concordance model and are
inconsistent with a simple model of evolution or dust as alternatives
to dark energy. Understanding dark energy may be the biggest current
challenge to cosmology and particle physics. To understand the nature
of dark energy, we seek to measure its two most fundamental
properties: its evolution {i.e., dw/dz}, and its recent equation of
state {i.e., w{z=0}}. SNe Ia at z>1, beyond the reach of the ground
but squarely within the reach of HST with ACS, are crucial to break
the degeneracy in the measurements of these two basic aspects of dark
energy. The SNe Ia we have discovered and measured with HST in Cycle
11, now double the precision of our knowledge of both properties. Here
we propose to quadruple the sample of SNe Ia at z>1 in the next two
cycles, complementing on-going surveys from the ground at z<1, and again doubling the precision of dark energy constraints. Should the current best fit model prove to be the correct one, the precision expected from the current proposal will suffice to rule out a cosmological constant at the 99% confidence level. Whatever the result, these objects will provide the basis with which to extend our empirical knowledge of this newly discovered and dominant component of the Universe, and will remain one of the most significant legacies of HST. In addition, our survey and follow-up data will greatly enhance the value of the archival data within the target Treasury fields for galaxy studies.

NIC2 10177

Solar Systems In Formation: A NICMOS Coronagraphic Survey of
Protoplanetary and Debris Disks

Until recently, despite decades of concerted effort applied to
understanding the formation processes that gave birth to our solar
system, the detailed morphology of circumstellar material that must
eventually form planets has been virtually impossible to discern. The
advent of high contrast, coronagraphic imaging as implemented with the
instruments aboard HST has dramatically enhanced our understanding of
natal planetary system formation. Even so, only a handful of evolved
disks {~ 1 Myr and older} have been imaged and spatially resolved in
light scattered from their constituent grains. To elucidate the
physical processes and properties in potentially planet-forming
circumstellar disks, and to understand the nature and evolution of
their grains, a larger spatially resolved and photometrically reliable
sample of such systems must be observed. Thus, we propose a highly
sensitive circumstellar disk imaging survey of a well-defined and
carefully selected sample of YSOs {1-10 Myr T Tau and HAeBe stars} and
{> app 10 Myr} main sequence stars, to probe the posited epoch of
planetary system formation, and to provide this critically needed
imagery. Our resolved images will shed light on the spatial
distributions of the dust in these thermally emissive disks. In
combination with their long wavelength SEDs the physical properties of
the grains will be discerned, or constrained by our photometrically
accurate surface brightness sensitivity limits for faint disks which
elude detection. Our sample builds on the success of the exploratory
GTO 7233 program, using two-roll per orbit PSF-subtracted NICMOS
coronagraphy to provide the highest detection sensitivity to the
smallest disks around bright stars which can be imaged with HST. Our
sample will discriminate between proposed evolutionary scenarios while
providing a legacy of cataloged morphologies for interpreting mid- and
far-IR SEDs that the recently launched Spitzer Space Telescope will

NIC2 10173

Infrared Snapshots of 3CR Radio Galaxies

Radio galaxies are an important class of extragalactic objects: they
are one of the most energetic astrophysical phenomena and they provide
an exceptional probe of the evolving Universe, lying typically in high
density regions but well-represented across a wide redshift range. In
earlier Cycles we carried out extensive HST observations of the 3CR
sources in order to acquire a complete and quantitative inventory of
the structure, contents and evolution of these important objects.
Amongst the results, we discovered new optical jets, dust lanes,
face-on disks with optical jets, and revealed point-like nuclei whose
properties support FR-I/BL Lac unified schemes. Here, we propose to
obtain NICMOS infrared images of 3CR sources with z<0.3 as a major enhancement to an already superb dataset. We aim to deshroud dusty galaxies, study the underlying host galaxy free from the distorting effects of dust, locate hidden regions of star formation and establish the physical characteristics of the dust itself. We will measure frequency and spectral energy distributions of point-like nuclei, expected to be stronger and more prevalent in the IR, seek spectral turnovers in known synchrotron jets and find new jets. We will strongly test unified AGN schemes and merge these data with existing X-ray to radio observations. The resulting database will be an incredibly valuable resource to the astronomical community for years to come.

NIC2 10149

The Coevolution of Supermassive Black Holes and Galaxies at z~3

The existence of strong correlations between the mass of supermassive
black holes and galaxy bulge properties implies that there is an
intimate connection between their formation and evolution. How do
supermassive black holes grow and how did the correlations come about?
Is the growth of supermassive black holes coeval with the growth of
the bulge, and is a bulge necessary for AGN activity at high z? We
propose to use HST NICMOS to image 9 low-luminosity broad-line AGNs at
z~3 in the restframe B- band, identified through the Lyman-break
technique. This sample is unique because the AGN luminosities are
comparable to Seyfert-like nuclei at z~3, and thus are some of the
lowest that have been selected optically. Because of the low total
luminosity of the sample, the hosts are likely to be Lyman-break
galaxies, which are believed to be the progenitor galaxies of the
local Hubble sequence. The goal is to directly detect their host
galaxies and to separate the AGN, in order to study the host galaxy
morphology and luminosity. From measurement of the bulge luminosity
and black hole mass {through available spectra}, we will study the
black hole-bulge coevolution out to z~3. We will also compare the
luminosity and morphology of these faint AGN hosts with the more
luminous and massive host galaxies found in previous HST studies of

NIC1 10143

Ultracool companions to the nearest L dwarfs

We propose to conduct the most sensitive survey to date for low mass
companions to nearby L dwarfs. We will use NICMOS to image targets
drawn from a volume-complete sample of 70 L dwarfs within 20 parsecs.
The combination of infrared imaging and proximity will allow us to
search for T dwarf companions at separations as small as 1.6 AU. This
is crucial, since no ultracool binaries are currently known with
separations exceeding 15 AU. Only 10 dwarfs in this sample have
previous HST observations primarily at optical wavelengths. With the
increased sensitivity of our survey, we will provide the most
stringent test to date of brown dwarf models which envisage formation
as ejected stellar embryos. In addition, our observations will be
capable of detecting binaries with mass ratios as low as 0.3, and will
therefore also test the apparent preference for equal-mass ultracool
binaries. Finally, our observations offer the best prospect to date of
detecting companions significantly cooler than the coolest t dwarf
currently known.


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

HSTAR 9722 ReAcq(2,1,1) requires multiple entries into CT to achieve
DataValid.  OTA SE review of the PTAS TC processing log for the
M_SA045P SMS, found that the ReAcq(2,1,1) required 4 CT entries on
FGS2 before achieving CT-DV. The ReAcq was successful and no science
impact should have been seen.

HSTAR 9723 Loss of Lock during Fine Lock Slew Test.HST lost fine lock
at 20:29:59 during the Fine Lock Slew Test. Vehicle returned to M2G
mode after loss of lock. Under investigation.

HSTAR 9724 Search Radius Limit Exceeded on FGS During SAA1.At
055/05:42:43 QF1SRLEX and QSRCHEXC flagged out of limits. These are
the FGS1 search radius limit exceeded flags. At the time we were in
gyro hold, and in an SAA level 1. Under investigation.


  • 17370-0  Continuous Engineering Coverage for F2G OOT @054/2346z
  • 17380-1  Restore K16ACLIM for FGS1 before return to 3Gyro @055/0122z
  • 17374-1  Table 213 Dump 2 @055/0129z
  • 17372-0  Return to 3-Gyro @055/0343z


                             SCHEDULED     SUCCESSFUL    FAILURE TIMES 
 FGS Gsacq                  25                       25 
 FGS Reacq                  5                         5 
 FHST Update               25                       25 
 OBAD                         16                       16 


Further analysis of the two-gyro ACS/HRC images obtained for program
10443 confirms the excellent ACS PSF performance reported on Tuesday,
February 22. Comparison of the ACS images with the corresponding
three-gyro data obtained last week reveals no significant differences.
No anomalies have been found.

The 2-gyro on orbit test successfully completed on February 23rd.  
The guide star acquisitions after the return to 3-gyro operations have
been successful.

SpaceRef staff editor.