Status Report

NASA Hubble Space Telescope Daily Report # 3777

By SpaceRef Editor
January 18, 2005
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NASA Hubble Space Telescope Daily Report # 3777

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT        # 3777




Main Sequence Turnoff Ages For Second Parameter Clusters in M33

In cycle 5, we were granted 40 orbits to study the early formation
history of M33 by investigating the nature of the “second parameter”
phenomenon among its globular star clusters. Discovered among the
globular clusters of the Milky Way more than 30 years ago, the “second
parameter” effect describes the degeneracy in the behavior of
horizontal branch {HB} morphology with metal abundance. This
degeneracy implies the existence of a second parameter, which, in
addition to metal abundance, influences the morphology of the HB. We
constructed {V, V-I} color-magnitude diagrams for 10 M33 halo globular
clusters. From these diagrams, we measured the cluster metallicities
and HB morphologies. Surprisingly, 8 of the 10 clusters display
extremely red horizontal branches, with most of the HB stars lying
near or on top of the red giant branch, yet their metal abundances are
in the range -1.6 <= [Fe/H] <= -1.0. A likely explanation is that the halo clusters in M33 are several Gyr younger than those in the Milky Way. To test this hypothesis, we propose to obtain main sequence turnoff photometry for two of our M33 clusters with similar metallicities but vastly differing HBs - a so-called `second parameter pair.' This will help to answer the question of whether age is the second parameter among the M33 halo clusters and provide an important clue to the overall nature of the second parameter effect.


NICMOS Post-SAA calibration – CR Persistence Part 1.

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.

ACS/WFC 10452

HST/ACS Mosaic of M51

A six-pointing ACS WFC mosaic of the galaxy pair M51 will be obtained
in four filters, B, V, I and H-alpha. Four orbits per pointing will
allow high-quality S/N images of the entire galaxy.


Black Hole Growth and the Black Hole Mass — Bulge Relations for AGNs

Recent work has shown that the mass of a black hole is tightly
correlated with the bulge mass of its host galaxy. This relation needs
to be understood in the context of black hole growth in its active
phase. Highly accreting AGNs, like narrow line Seyfert 1 galaxies
{NLS1s}, are found to lie below the black hole mass — bulge velocity
dispersion correlation of normal galaxies and broad line AGNs. This
result was obtained using FWHM{[OIII]} as a surrogate for the bulge
velocity dispersion. To test this result we propose to obtain high
resolution images of 10 NLS1s that do not lie on the black hole
mass–sigma relation and measure accurate bulge parameters {luminosity
and effective radius}. We will obtain an alternate handle on the bulge
velocity dispersion through the fundamental plane relations and also
find the locus of these NLS1s on the black hole mass–bulge luminosity
plane. Testing this result is crucial to understanding the role of
accretion on black hole growth, the observed correlations of the black
hole mass with the bulge, and the formation and evolution of galaxies.

ACS/WFC 10429

Streaming Towards Shapley: The Mass of the Richest Galaxy
Concentration in the Local Universe

The 600 km/s motion of the Local Group {LG} with respect to the cosmic
microwave background {CMB} is now known to high accuracy. However, its
precise origin remains poorly understood. The contribution to the
motion from the pull of the rich Shapley supercluster at z = 0.048 is
particularly controversial. This extreme mass concentration contains
more than 20 Abell clusters within 35 Mpc of its very rich central
cluster A3558, and is recognized as both the optically richest and the
most X-ray luminous structure in the local {z < 0.1} universe. Yet, published values for the mass of Shapley continue to differ by an order of magnitude, and recent estimates of its pull on the LG range from negligible {20 km/s} to highly significant {300 km/s or more}. Here we propose to resolve this key issue by using ACS to measure high-precision surface brightness fluctuation {SBF} distances in order to make a direct measurement of the infall towards Shapley. We will target three Shapley foreground clusters where the infall is expected to be high {possibly 1000 km/s or more}, as well as the Shapley core, in order to test the assumption that it is at rest in the CMB. Prior to ACS, the Shapley region was unreachable for SBF, but ACS doubles the distance range of the SBF method with HST, enabling the distances to be measured to the required accuracy. The proposed measurements will place a firm limit on the largest mass fluctuation in the nearby universe and finally determine its contribution to the observed CMB dipole.


ACS Coronagraphic Imaging of Herbig Ae/Be Stars

We can indirectly learn about the planet formation process by studying
proto-planetary dust disks. In this proposed observational program, we
focus on Herbig Ae/Be stars which are pre-main sequence intermediate
mass stars {2-10 solar masses} thought to be immediate precursors to
the Vega-excess stars like Beta Pictoris. We propose to take ACS
coronagraphic images in the F606W filter of 6 Herbig Ae/Be stars, all
of which have well constrained spectral energy distributions and are
nearby {<200pc}, suggesting possible disk sizes of 3" or larger in radius. We use the recent ACS coronagraph image of Herbig Ae/Be star, HD 141569, which shows a spectacular circumstellar disk, as a template for observing strategy and exposure time estimates. Our observing program involves contemporaneous comparison stars that will be used to subtract the point spread function. These images will constrain the size and possibly, the morphology of the circumstellar dust that may have disk, envelope or disk+envelope geometries. We will analyze these images quantitatively using 2-Dust, an axisymmetric radiative transfer dust code, to derive basic physical parameters of the dusty circumstellar matter such as mass, size, geometry, inclination angle and grain properties.

ACS/WFC 10421

Searching for Ancient Mergers in Early Type Host Galaxies of Classical

Recent HST imaging of QSO host galaxies indicates that at least a
large fraction of QSOs reside in seemingly undisturbed elliptical
hosts. However, our deep Keck spectroscopy of a sample of these host
galaxies indicates that many of these objects were involved in a major
starburst episode between 0.6 and 1.6 Gyr ago. We propose to obtain
very deep ACS WFC observations of the five hosts in this sample that
have the most reliable age determinations to search for fine structure
indicative of a past merger event and to test the hypothesis that the
elliptical hosts are the products of relatively recent merger events
rather than old galaxies which formed at high redshifts. By
establishing a firm connection between ancient mergers and the aging
starbursts in these classical QSOs, we will be able to estimate the
fraction of the total QSO population that results directly from
mergers accompanied by massive starbursts and to place constraints on
the duty cycle for QSO activity.


Highly episodic mass loss on the AGB: imaging in scattered stellar

We have discovered that some nearby bright carbon stars have detached
circumstellar shells, emitting in CO mm lines as well as in visual
stellar light scattered by dust and atoms {the resonance lines of NaI
and KI}. The optical light is up to 35% linearly polarized. The shells
are remarkably spherical, but both the CO data and the optical
pictures show pronounced inhomogeneities on smaller {marginally
resolved} scales. The latter fact introduces considerable
uncertainties in mass-loss-rate estimates. We ascribe the existence of
the shells to the He-shell flashes, and the inhomogeneities to
hydrodynamic instabilities. However, the different observables {CO,
atoms, dust} indicate significantly different structural patterns. In
order to understand the different components of the shells, their
interaction and origin, it is necessary to improve the imaging of the
shells. In view of their faintness, relative to the stellar light
scattered in the Earth’s atmosphere, this can only be accomplished by
using the HST. Maps of the distribution of the dust at high spatial
resolution will efficiently constrain theoretical work on the origin
of the shells and their evolution, and the inhomogeneities in them. We
may be able to separate the dust and atomic scattered light
components. Mass loss from carbon stars and other AGB stars contribute
significantly to the abundances of many chemical elements {C, N,
s-elements} and is not well understood. The present study may lead to
important improvements in the study of mass-loss rates and mechanisms,
and thus for nucleosynthesis in general.

NIC3/WFPC2 10403

Ultraviolet Imaging of the UDF

The Hubble Deep Field North has uninterrupted observations at
wavelengths from Far-UV through NICMOS H-band, but the UDF goes no
bluer than B-band. We propose to complete the UDF coverage with deep
ultraviolet imaging of the Ultra-Deep Field {UDF} with the ACS-SBC in
the Far-UV {1500 Angstrom} and WFPC2 in the Near-UV {F300W}. We will
reach point source limits of ABmag=28.5, a factor of ten fainter than
the GALEX ultradeep surveys. Our dataset will add to the value of the
UDF legacy, and requires the unique capabilities of HST. In the spirit
of the UDF, we submit this proposal in the Treasury category. We
request a modest allocation of observing time for a Treasury program:
62 orbits. We will provide science quality images and photometric
catalogs to enable a range of research topics by the community. The
science goals of the team are to investigate the episode of strong
star formation activity in galaxies out to z=1, through the rest-frame
FUV luminosity function and the internal color structure of galaxies.
Far-UV number counts suggest that moderate redshift {z~0.5} starbursts
are undergoing a single, rapid burst of star-formation. We will
investigate this result by measuring the faint-end slope, alpha, of
the luminosity function. We will measure the star formation properties
of moderate redshift starburst galaxies and compare their morphologies
in the UV, optical, and near-IR. This catalog of starbursts will also
be important to the astronomical community in correlating unobscured
star-formation with the sources detected in the Spitzer Space
Telescope legacy observations of the field. With the high spatial
resolution data, will set strict limits on the flux escaping in
intermediate redshift {1

ACS/HRC/WFC/WFPC 10384 2 Focus Monitor

The focus of HST is measured from WFPC2/PC and ACS/HRC images of
stars. Multiple exposures are taken in parallel over an orbit to
determine the influence of breathing on the derived mean focus.
Observations are taken of clusters with suitable orientations to
ensure stars appear in all fields.

NIC1/NIC2/NIC3 10380

Cycle 13 NICMOS dark current, shading profile, and read noise
monitoring program

The purpose of this proposal is to monitor the dark current, read
noise, and shading profile for all three NICMOS detectors throughout
the duration of Cycle 13. This proposal is an essentially unchanged
continuation of PID 9993 which cover the duration of Cycle 12.


ACS CCDs daily monitor- cycle 13 – part 1

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 programme will be
for the entire lifetime of ACS.

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.

WFPC2 10357

Saturn’s Inner Satellites at True Opposition

We request one HST orbit to observe Janus, Epimetheus, Mimas, and
Enceladus with WFPC2 exactly at opposition, when the Earth transits
the center of the solar disk seen from Saturn on UT 13/14 January
2005. Data obtained at this unique viewing geometry are essential to
determining physical properties of the moon’s surface, related to its
emplacement and evolution, and critical for the interpretation of
photometric data obtained by Cassini at higher phase angles. This
single observation will be the capstone of 9 years of legacy HST WFPC2
observations of the Saturnian system {Cycles 6-12, R. French, PI} from
which we have constructed precise, multiwavelength phase curves which
demonstrate how the reflectance of these satellites varies with solar
phase angle from 0.07 to 6.4 degrees. Each satellite exhibits a
dramatic increase in brightness, or “opposition effect”, as phase
angles decrease below 1 degree. Since 1998 {Cycle 7} the minimum
observable phase angle at opposition has decreased each year to 0.07
degrees in Cycle 12; however, the absolute minimum observable phase
angle, about 0.02 degrees {limited by the angular size of the Sun
viewed from Saturn}, has not been accessible until Cycle 13. Using the
same set of broadband filters for continuity with our previous
programs, we will place observations made during the Earth transit on
the existing UVBRI phase curves and establish the amplitude of each
satellite’s opposition surge. From these observations we will
determine surface properties such as porosity, grain size distribution
and particle opacity using radiative transfer models. While the
Cassini spacecraft will obtain images at larger phase angles, it will
miss entirely the narrow brightness surge near opposition due to
orbital constraints. Because these inner satellites will be either
lost in or contaminated by the glare of the fully open rings, they are
not accessible to ground-based telescopes. The 2005 opposition
presents the only opportunity for HST to observe the Saturnian system
during this rare planetary alignment. The next transit of Earth across
the solar disk seen from Saturn occurs in 2020; the next central
transit occurs in 2049.


The Formation History of Andromeda

We propose deep observations of Andromeda’s outer disk and giant tidal
stream, to reconstruct their star formation histories. As the nearest
giant galaxy, Andromeda offers the best testing ground for
understanding galaxy formation and evolution. Given the dramatic
increase in sensitivity offered by the ACS, we can now resolve stars
on the old main sequence in the other giant spiral of the Local Group,
and employ the same direct age diagnostics that have been used for
decades in the study of Galactic globular clusters. In Cycle 11, we
successfully observed a field in the Andromeda halo and constructed a
deep color-magnitude diagram reaching well below the oldest main
sequence turnoff. In Cycle 13, we propose to extend these observations
to the outer disk and tidal stream of Andromeda, to constrain their
star formation histories and compare them to that of the halo. The
combined observations from these two programs will offer a dramatic
advance in our understanding of the overall evolution of spiral

NIC/NIC3 10226

The NICMOS Grism Parallel Survey

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

ACS/WFC 10217

The ACS Fornax Cluster Survey

The two rich clusters nearest to the Milky Way, and the only large
collections of early- type galaxies within ~ 25 Mpc, are the Virgo and
Fornax Clusters. We propose to exploit the exceptional imaging
capabilities of the ACS/WFC to carry out the most comprehensive
imaging survey to date of early-type galaxies in Fornax: the ACS
Fornax Cluster Survey. Deep ACS/WFC images — in the F475W {g’} and
F850LP {z’} bands — will be acquired for 44 E, S0, dE, dE, N and dS0
cluster members. In Cycle 11, we initiated a similar program targeting
early-type galaxies in the Virgo Cluster {the ACS Virgo Cluster
Survey; GO-9401}. Our proposed survey of Fornax would yield an
extraordinary dataset which would complement that already in hand for
Virgo, and allow a definitive study of the role played by environment
in the structure, formation and evolution of early-type galaxies and
their globular cluster systems, nuclei, stellar populations, dust
content, nuclear morphologies and merger histories. It would also be a
community resource for years to come and, together with the ACS Virgo
Cluster Survey, constitute one of the lasting legacies of HST.

ACS/HRC 10199

The Most Massive Galaxies in the Universe: Double Trouble?

We are proposing an HST snapshot survey of 70 objects with velocity
dispersion larger than 350 km/s, selected from the Sloan Digital Sky
Survey. Potentially this sample contains the most massive galaxies in
the Universe. Some of these objects may be superpositions; HST imaging
is the key to determining if they are single and massive or if they
are two objects in projection. The objects which HST imaging shows to
be single objects are interesting because they potentially harbor the
most massive black holes, and because their existence places strong
constraints on galaxy formation models. When combined with ground
based data already in hand, the objects which HST imaging shows are
superpositions provide valuable information about interaction rates of
early- type galaxies as well as their dust content. They also
constrain the allowed parameter space for models of binary
gravitational lenses {such models are currently invoked to explain
discrepancies in the distribution of lensed image flux ratios and


The Star Formation History and Metallicity Evolution of M33: A
Comprehensive Study of Disk Evolution

We will obtain deep, panchromatic imaging photometry of stellar
populations in four fields ranging from 0.5 to 4 scale lengths across
the disk of the Local Group spiral M33. The observations are designed
to detect the oldest main-sequence turnoffs in three outer disk
fields, and to reach the crowding limit in the innermost field. We
will combine the photometry data with information we already have
in-hand on abundances from stars and H II regions in M33 to derive the
star formation history and metallicity evolution of the M33 disk. The
information from our four fields will allow us to obtain {1} the ages
of the oldest disk stars and the radial variation of their ages; {2}
the radial variation of the star formation history and its nature
{e.g., constant, declining, or bursting}; and {3} the metallicity
distribution in each field and the time evolution of the metallicity
gradient. Our team, an experienced mix of photometrists,
spectroscopists, and galaxy evolution theorists, will use the results
from this program to construct a comprehensive chemo- dynamical model
for the M33 disk. This detailed study of M33 will be a key in
developing an understanding of the formation and evolution of disks
that can be applied to studies of disks at both low and high redshift,
and will also yield a wealth of information on stellar populations,
chemical evolution, and star clusters that will be of great value to
future investigators.

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.

ACS/WFC/NIC3 10127

Imaging a protocluster at z=3.1: Effects of environment and evolution
on galaxy populations in the early universe

We propose imaging a rich protocluster, 0316-26 at z = 3.13, with 31
confirmed Lya cluster members. The bright radio galaxy host is
identified with the progenitor of the dominant cluster galaxy. Because
its redshift places Lya into an ACS narrow-band filter, the
protocluster provides a unique laboratory for studying galaxies at a
crucial epoch in the evolution of the Universe. We shall {i} measure
and compare sizes, morphologies and colors of galaxies from
populations detected using 4 different selection techniques {Lyman and
4000A breaks, Lya and [OIII] excesses}, {ii} study effects of an
overdense environment by comparing the properties of protocluster
galaxies with z~3 field galaxies from GOODS, {iii} study effects of
evolution by relating our data to observations of similar
protocluster/cluster targets at redshifts z = 4.1, 2.2, and 1.2, and
{iv} constrain the formation of the most massive cluster galaxies by
investigating the spatial distribution, Lya equivalent widths and
other properties within the 5″ radio galaxy host. The ultimate aim is
to disentangle the history of structure development and stellar
evolution for rich clusters of galaxies.

WFPC2 10112

HST Observations of Astrophysically Important Visual Binaries

This is a continuation of a project begun in Cycle 7 and continued up
through Cycle 11. The program consists of annual or biannual WFPC2 or
FGS observations of three visual binary stars that will ultimately
yield fundamental astrophysical results, once their orbits and masses
are determined. Our targets are the following: {1} Procyon {P = 41
yr}, for which our first WFPC2 images yielded an extremely accurate
angular separation of the bright F star and its much fainter
white-dwarf companion. Combined with ground-based astrometry of the
bright star, our observation significantly revised downward the
derived masses, and brought Procyon A into excellent agreement with
theoretical evolutionary tracks for the first time. With the continued
monitoring proposed here, we will obtain masses to an accuracy of
better than 1%, providing a testbed for theories of both Sun- like
stars and white dwarfs. {2} G 107-70, a close double white dwarf {P =
19 yr} that promises to add two accurate masses to the tiny handful of
white-dwarf masses that are directly known from dynamical
measurements. {3} Mu Cas {P = 21 yr}, a famous metal- deficient G
dwarf for which accurate masses will lead to the stars’ helium
contents, with cosmological implications.


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

HSTAR 9665: GS Acquisition (1,3,3)required two attempts to enter FL
with SRLE @ 08:09:06Z. Under investigation.



  • 0900-1 COMMAND PROBLEM @ 017/0502z
  • 0916-0 Tabulation of Slew Attitude Error (Miss-distance) @ 017/0056z
  • 0900-1 COMMAND PROBLEM @ 017/0502z
  • 0916-0 Tabulation of Slew Attitude Error (Miss-distance) @ 017/0056z

                           SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS Gsacq                33                       33
FGS Reacq                26                       26
FHST Update              54                      54


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