Status Report

NASA Hubble Space Telescope Daily Report #3898

By SpaceRef Editor
July 21, 2005
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HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT #3898

PERIOD COVERED: UT July 08-10, 2005 (DOY 189-191)

OBSERVATIONS SCHEDULED

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.

FGS 10614

Internal Structure and Figures of Binary Asteroids

The goal of this proposal is to obtain very important information on
the internal structure of a number of asteroids, and insight on the
gravitational reaccumulation-process after a catastrophic disruptive
collision. High resolutions observations with the HST/FGS
interferometer are proposed to obtain high precision data for the
topographic shape and size of a number of selected asteroids. Here we
focus on objects with satellites, hence with known masses, so that the
bulk density and porosity will be derived in the most accurate manner.
This will yield plausible estimates on the internal properties of the
objects, test wether they are close or not to figures of equilibrium
{in terms of shape and adimensional rotational frequency}, and provide
estimates of their relative density. The HST/FGS in interferometric
mode is an ideal facility to carry out this program.

ACS/HRC 10435

Merger-Induced Populations in Early-Type Galaxy Cores

Hierarchical formation models predict that early-type galaxies are
built up over an extended period from mergers of smaller systems, a
process which should leave long- lived signatures in their light
profiles and stellar population colors. Merger events should have
continued up to relatively recent times {the last 1-5 Gyr}, and many
ellipticals and S0 bulges should therefore show evidence of multiple,
discrete, intermediate-age populations. Although there is substantial
observational support for a dissipational merger origin for some
early-type galaxies, most do not exhibit the expected anomalies in
either their light profiles or color distributions. However, existing
searches {mainly in the V and I bands} have not probed very deeply.
Here we propose high resolution, broad-band, near-ultraviolet
{2500-3400 A} imaging of the cores of bright early-type galaxies. This
is the most sensitive probe available for the detection of
spatially-segregated, multiple population components with ages in the
range 1-5 Gyr. Our sample consists of dust- and AGN-free systems with
both normal and mildly anomalous central light profiles. There is very
little existing information on the near-UV structure of early-type
galaxies, and our program would effectively explore new terrain.

NIC1/NIC2 10410

Anisotropy and obscuration in the near-nuclear regions of powerful
radio galaxies

Despite the success of the orientation-based unified schemes for
powerful radio sources, we are still far from understanding the
distribution of obscuring material in the near-nuclear regions of such
sources, and how this distribution evolves with radio power. Following
on from our highly successful Cycle 7 pilot observations of Cygnus A,
we propose a near-IR polarimetric survey of a complete sample of
powerful radio galaxies in order map the near-nuclear illumination
cones, and investigate the distribution of obscuring material on a 0.1
to 1kpc scale. In particular, the observations will allow us to test
the “receding torus model” which predicts that the opening angles of
the illumination cones are smaller in low redshift/low power radio
galaxies than in their high redshift/high power counterparts.We will
also investigate whether AGN- and jet-driven outflows have a
substantial effect on distribution of obscuring material by “hollowing
out” the quasar illumination cones in the more powerful sources.
Finally, by using our polarization maps to search for signs of
intrinsic anisotropy in the near-IR continuum within the cones, we
will investigate the geometry of the near-IR continuum emitting
regions close to the quasar nuclei. These observations are not only
crucial for our understanding of radio source unification, but also
provide key information about the effects of AGN-induced outflows on
the ISM of the host galaxies.

ACS/HRC/WFC/NIC2 10399

Accurate and Robust Calibration of the Extragalactic Distance Scale
with the Maser Galaxy NGC4258 II

The extragalactic distance scale {EDS} is defined by a comparison of
Cepheid Period- Luminosity {PL} relations for nearby galaxies and the
LMC, whose uncertain distance is thereby the SOLE anchor. Studies of
masers orbiting the central black hole in NGC4258 have provided the
most accurate extragalactic distance ever {7.2+/-0.5 Mpc}, and new
radio data and analysis techniques will reduce the uncertainty to < 3.5% {0.07 mag} by 2005. Since this distance is well determined and based on geometric arguments, NGC4258 can provide a much needed new anchor for the EDS. Ultimately, the combination of an independent measurement of H0 and measurements of CMB fluctuations {e.g., WMAP} can be used to directly constrain cosmological parameters including the equation of state of dark energy. In our Cycle 12 proposal, we defined a program spanning two cycles. The Cycle 12 portion was accepted. We have acquired WFC images and are constructing well sampled PL relations in 3 colors {BVI}. The purpose of the Cycle 13 observations is to address systematic sources of error and is crucial for the success of the entire program. To disentangle the effects of reddening and metallicity, and to characterize the effects of blending, we require 50 orbits to obtain H-band photometry {NICMOS/NIC2} and high resolution images {ACS/HRC}.

ACS/WFC/WFPC2/NIC 10395

3 Environmental drivers of galaxy evolution: an HST survey of dwarf
galaxy morphologies in the Abell

Galaxies in dense environments are subject to numerous physical
processes that leave a lasting impact, yet studies of galaxy evolution
to date have been limited to the most luminous galaxies — those least
sensitive to environmental influence. We propose to explore the
environmental drivers of DWARF galaxy evolution: with a mosaic of 9×9
ACS pointings in F606W we will determine morphologies for ~1200
galaxies down to M_V=-14 in the A901/902 supercluster, spanning 3×3
Mpc at z=0.16. The deep ACS data will allow us to probe their surface
brightness profiles, shapes, sizes, asymmetry and fine structure such
as tidal features. With the addition of extensive existing multi-
wavelength data, we will probe the dependence of these important
parameters on dark matter content {from weak lensing maps}, the hot
intercluster medium {from deep XMM- Newton imaging}, and local galaxy
density {from hyper-accurate COMBO-17 photometric redshifts with delta
z=0.02 to m_R=24}, thus disentangling the various environmental
processes shaping dwarf galaxy evolution. Furthermore, the 8000+
background galaxies at 0.2 < z < 1.0 will be of enormous scientific benefit for additional studies of weak lensing, AGN host galaxies, the morphology-density relation, and the merger rate as a function of redshift.

ACS/WFC/WFPC2 10394

Deep imaging of newly discovered globular clusters in the outer halo
of M31

Globular clusters {GCs} are fossil relics with which we can
investigate the processes of galaxy formation and growth. We have
recently discovered a sample of GCs, as part of a very wide area CCD
survey of M31. These clusters span a range in projected galactocentric
distance of 20 – 80 kpc, more than double the radii of the previous
most remote known GC. Here we apply for deep ACS images of 13 GCs,
which will allow us to study their stellar populations, line-of-sight
distances and structural parameters. These will be used to: a}
Investigate the merger history of M31, through an examination of
variations in the RGB and HB morphologies, particularly to obtain
metallicities and check for the presence of any second parameter
effect in the HB. d} Determine, in conjuction with ground-based
spectroscopy, the dynamical mass of M31 at large radius, providing a
direct probe of the mass distribution of its dark halo.

ACS/HRC/WFC 10389

ACS CCDs daily monitor – Cycle 13 – Part 2

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This program will be
for the entire lifetime of ACS.

NIC1/NIC2/NIC3 10381

Photometric Stability

This NICMOS calibration proposal carries out photometric monitoring
observations during Cycle 13. The format of the program is identical
to that of the Cycle 12 program 9995

ACS/WFC/HRC 10378

ACS Polarimetry Calibration

Observations are made of the Boomerang Nebula {highly polarized
reflection nebula} to calibrate the ACS polarizers.

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.

ACS/HRC/NIC2 10244

Coronagraphic imaging of Eta Corvus: a newly discovered debris disk at
18 pc

Debris disks are one of the final stages in the evolution of planetary
systems. High resolution imaging of debris disks has been instrumental
to our understanding of the status of planet formation in these
systems. The detection of clumps and asymmetries has even led to the
detection of unseen planets. However, just six resolved disks exist in
the literature. Eta Crv is now the seventh debris disk confirmed with
imaging, and was discovered in a recent sub-mm survey of nearby stars.
Its proximity {18 pc} and similarity to Beta Pic, one of the “big
four” Vega-type disks, makes it an excellent candidate for a high
resolution coronagraphic study of its disk structure. Modeling of this
structure at many wavelengths will set hard constraints on its unseen
planetary system and the distribution of particles from micron to
kilometer in size, thus significantly extending our understanding of
the planet formation processes in debris disks

ACS/WFC 10154

Morphology of z ~ 7-10 galaxies viewed through gravitational telescopes

The aim of these observations is to obtain deep z/ACS and H/NICMOS
images in the core of two lensing clusters, A1835 and AC114, where a
few z ~ 7-10 galaxy candidates have been selected from our ultra-deep
JHK imaging program with Isaac/VLT. Spectroscopic observations have
allowed to confirm 2 of these candidates thanks to the detection of
faint emission lines identified as Lyman alpha at z=7.2 and 10. Our
HST project is focused on two main goals: {1} the morphological
confirmation of galaxy candidates lying near critical lines, and {2}
the determination of the physical scales involved in star-forming
regions at z ~ 7-10. These goals should have important implications on
our present knowledge of the galaxy formation process in the early
Universe.

ACS/WFC 10101

The Region of the Hydrogen-Burning Limit in Omega Centauri and 47
Tucanae

We propose a photometric study of the lower main sequences of Omega
Cen and 47 Tuc, down to the region of the H-burning limit, which the
deeper faintness limit of ACS will allow us to reach. For the faintest
stars, proper-motion separation of cluster from field is essential;
hence we include Cycle 13 observations. The resulting color–
magnitude diagrams {CMDs} and luminosity functions {LFs} will allow
study of stars in a mass regime and metallicity that have never been
accessible before, and will serve as an important check on theories of
the structure of low-mass stars. These are the 2nd- epoch
observations.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#9880 – SAVED FGS ERROR NULL BIAS (QSFGENB0) @ 189/1919z During
successful GSacq(1,2,1) of 189/19:14:25, a measuremnet was made of the
V1 (roll) error during sequential update. This measured value of the
error -1073.130 a-s “Err Null Bias (QSFGENB0)” was saved in the
telemetry parameter “Saved FGS Error Null Bias (QSFGENB0)” at
189/19:19:08.

#9881 – GSacq(1,3,1) results in finelock backup (1,0,1) scan step lmt
exc on FGS-3 @ 189/2054z The GSacq(1,3,1) scheduled at 189/20:50:22 –
20:58:24 Z resulted in finelock backup (1,0,1) using FGS-1, due to
scan step limit exceeded on FGS-3 during acquisition walkdown. The
Secondary FGS has the same star id (0547900910) as HSTAR 9871.

#9882 – GSacq(1,2,1) results in finelock backup (1,0,1) scan step lmt
exc on FGS-2 @ 189/2230z The GSacq(1,2,1) scheduled at 189/22:26:15 –
22:34:17 Z resulted in finelock backup (1,0,1) using FGS-1, due to
scan step limit exceeded on FGS-2 duirng acquisition walkdown. The
Secondary FGS has the same star id (0547900910) as HSTAR 9871.

#9883 – GSAcq (2,1,1) Failed to RGA Control, due to search radius
limit exceeded on FGS-1 @ 190/1016z The GSACQ(2,1,1) scheduled at
190/10:11:10 – 190/10:18:32 Failed to RGA Control due to search radius
limit exceeded on both FGS1 and FGS2.

#9886 – GSACQ(1,2,1) fine lock backup, scan step limit exceeded on
FGS-1 @ 190/1917z GSACQ(1,2,1) at 190/19:13:24 ended in fine lock
backup on FGS 2 due to scan step limit exceeded twice on FGS 1 at
19:17:20 and 19:19:01.

#9887 – GSACQ(1,2,1) fine lock backup (2,0,2), scan step limit
exceeded on FGS 1 @ 190/2225z GSACQ(1,2,1)@190/22:25:57 resulted in
fine lock backup(2,0,2)on FGS 2 due to scan step limit exceeded twice
on FGS 1 at 22:29:10 and 22:30:52.

COMPLETED OPS REQUEST:

#17464-0 – Genslew for proposal 10330 – slot 8 @ 189/1725z

#17465-0 – Genslew for proposal 10330 – slot 11 @ 189/1727z

#17466-1 – Real Time Map @ 190/1342z

#17467-1 – ARU/PRT @ 190/1424z

#17468-0 – Real Time Map @ 190/1523z

COMPLETED OPS NOTES: (None)

              SCHEDULED     SUCCESSFUL 
 FGS Gsacq       25             24 
 FGS Reacq       19             16 
 FHST Update     36             36 

SIGNIFICANT EVENTS: (None)

SpaceRef staff editor.