HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3813
PERIOD COVERED: DOY 68
OBSERVATIONS SCHEDULED
ACS/HRC 10255
A Never Before Explored Phase Space: Resolving Close White Dwarf / Red
Dwarf Binaries
We propose an ACS Snapshot imaging survey to resolve a well-defined
sample of highly probable white dwarf plus red dwarf close binaries.
These candidates were selected from a search for white dwarfs with
infrared excess from the 2MASS database. They represent unresolved
systems {separations less than approximately 2" in the 2MASS images}
and are distributed over the whole sky. Our HST+ACS observations will
be sensitive to a separation range {1-20 AU} never before probed by
any means. The proposed study will be the first empirical test of
binary star parameters in the post-AGB phase, and cannot be
accomplished from the ground. By resolving as few as 20 of our ~100
targets with HST, we will be able to characterize the distribution of
orbital semi- major axes and secondary star masses.
ACS/HRC 10330
Coronagraphic search for disks around nearby stars
We will use the coronagraphic and imaging modes of the High Resolution
camera to study of the role of circumstellar disks in planetary system
formation over timescales of ~1-1000 Myr. Our targets comprise pre
Main-Sequence {MS} and MS stars, selected by infrared excess, and
targets selected from SIRTF surveys. Some targets, like Beta Pictoris
have debris disks that have been detected at optical or near-IR
wavelengths, while others have disks inferred from mid-IR or ISO
observations. We will obtain multicolor images of each target's
circumstellar environment for the purpose of {1} detecting and
characterizing disk morphologies over all scales {including warps and
regions of enhanced or depleted density}, and {2} seeking evidence of
embedded planets. Direct and occulted images will be recorded for
studying the disks within 2 arcseconds of these targets; the
coronagraph will be used to image the outer regions of the disks.
Together with existing infrared observations, we will provide
constraints on the sizes, distribution, and composition of dust
grains. Unconfirmed disks will first be imaged in F606W, and if they
exist we may later observe them in F435W and F814W.
ACS/HRC/WFC 10117
The Co-Evolution of Star Formation and Powerful Radio Activity in
Galaxies
We will carry out a STIS/NUV-MAMA snapshot imaging survey of the most
compact powerful radio galaxies, the Gigahertz Peaked Spectrum {GPS}
sources and Compact Steep Spectrum {CSS} sources. These objects are as
powerful as the large radio doubles but are much smaller {and younger}
and are crucial to our understanding not only of how radio-loud active
galactic nuclei {AGN} form and evolve, but also what role they play in
the evolution of galaxies. A very direct and robust way to address
these issues is by high resolution imaging of the host galaxies of
these sources in the UV. This has never been done before for a sample
of these very compact sources, since previous HST/UV imaging programs
have focussed on the larger radio galaxies. The UV emission can
provide crucial information about any recent star formation that may
have occurred as a result of ongoing accretion, mergers, interactions,
or triggering by the radio source. By comparing the starburst
properties of GPS, CSS, and large scale radio sources, we will be able
to constrain the evolution of massive star formation as a function of
the relative age of the radio source. {Note, due to the failure of
STIS, these observations will be carried out using the ACS/HRC}.
ACS/HRC/WFC 10214
ACS/HRC imaging of two very bright ultra-luminous X-ray sources {ULXs}
We propose broad- and narrow-band ACS/HRC imaging of two very bright
ultraluminous X-ray sources {ULXs} in NGC 4559. Our main objectives
are: to identify the optical counterparts; to determine their masses
and evolutionary stages; to determine the nature of mass transfer in
the ULX systems; to determine the properties of the stellar population
in the ULX fields {eg, metal abundance, age}. With these observations,
integrated with our Chandra, XMM-Newton, HST/WFPC2 and CHFT data, we
will test the models for the nature and mechanisms of formation of the
accreting black holes in ULXs. Moreover, one of the two ULXs is in a
peculiar star-forming complex: we have suggested that it is an
expanding wave of star-formation triggered by a dwarf galaxy plunging
through the outer disk of NGC 4559. The ACS observation will also
allow us to test this hypothesis.
ACS/HRC/WFC 10367
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.
ACS/HRC/WFC 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/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.
NIC1 10415
A Proper Motion Study of the Ionized Gas in the Vicinity of the
Galactic Center Black Hole
The Galactic Center's distance of only 8 kpc provides a unique
opportunity to study the interaction of a supermassive black hole with
its environment at a level of detail not possible for other galaxies.
We propose to observe the inner parsec of the Galaxy in the Paschen
alpha line with Camera 1 of NICMOS in order to study the kinematics of
ionized gas in the vicinity of the supermassive black hole coincident
with Sgr A*. Our previous GO program 7842 yielded detailed Pa alpha
images revealing complex, filamentary structure at 0.16 arcsec {0.006
pc} resolution. However, proper motions could not be robustly derived
from that data set due to the fact that the two epochs were spaced
only 7 months apart. In order to follow up on preliminary results
showing evidence for high proper motions within 2'' of Sgr A* and to
characterize the rest of the central parsec, we propose to obtain two
additional epochs within Cycle 13 so that the dataset will comprise
independent measurements of the proper motions ranging from intervals
of 5 months to 7 years, with the 7 year interval giving a 1 sigma
accuracy of 45 km/s. These will be combined with existing radial
velocity measurements to provide the first complete characterization
of the kinematics of the ionized gas in the central parsec. This is
crucial to interpreting the relative importance of gravitational
forces, stellar winds, and possible accretion onto or outflow from the
black hole. These observations may possibly lead to the first direct
observation of gas in the process of accretion {or ejection via a jet}
associated with the Galactic Center black hole. The kinematics of the
gas may also imply that accretion may be inhibited, and this could
explain the low luminosity of Sgr A*.
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.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.) None
COMPLETED OPS REQs:
- 17391-3 NICMOS CS FSW v4.0Ce Installation @ 068/2255z
- 17398-0 NICMOS Interim Checksum @ 068/1310z, 068/2255z
OPS NOTES EXECUTED: None
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS Gsacq 08 08
FGS Reacq 07 07
FHST Update 14 14
LOSS of LOCK
SIGNIFICANT EVENTS:
NICMOS CS Flight Software (FSW) Load: Steps 22 through 41 of Ops
Request 17391 were completed successfully on 068/2300. This completed
the load of NICMOS CS FSW to EEPROM.
