A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Hubble
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Daily 3665



 
 
Thread Tools Display Modes
  #1  
Old August 2nd 04, 05:12 PM
external usenet poster
 
Posts: n/a
Default Daily 3665

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3665

PERIOD COVERED: DOYs 212-214

OBSERVATIONS SCHEDULED

NIC2 9856

A near-IR imaging survey of submm galaxies with spectroscopic redshifts

Submillimeter {submm} surveys with SCUBA have identified a population
of obscured star-forming and active galaxies at high redshift. Our
recent spectroscopic campaigns with the Keck-10m telescope have
uncovered redshifts for 37 SCUBA galaxies. The wide redshift range of
the radio identified submm population {z=1-4} implies that many
varieties of sources driven by different physical processes may be
selected in a submm survey. We propose to use HST-NICMOS, ACS to
obtain 2-filter images of a sample of 15 SCUBA galaxies with redshifts
spanning z=0.8-3.5. Our goal is to understand what physical process
{major mergers?} drive their strong evolution and great luminosities,
and what the implications are for galaxy evolution models.

ACS/STIS/MA2 9829

HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet

As the nearest galaxy with an optical jet, M87 affords an unparalleled
opportunity to study extragalactic jet phenomena at the highest
resolution. During 2002, HST and Chandra monitoring of the M87 jet
have detected a dramatic flare in knot HST-1 located ~1" from the
nucleus. Its brightness has increased ten-fold in the optical band,
and continues to increase, and the X-rays show a similarly dramatic
outburst. In both bands this HST-1 now rivals the nucleus in
brightness. To our knowledge this is the first incidence of an optical
or X-ray outburst from a jet region which is spatially distinct from
the core source; this presents an unprecedented opportunity to study
the processes responsible for non-thermal variability and the X-ray
emission. We propose four epochs of HST/ACS monitoring during Cycle
12, as well as seven epochs of Chandra/ACIS observation {5ksec each}.
We also include a brief STIS observation that will be used with prior
STIS data to measure proper motions, and ACS polarimetry to map the
magnetic field structure. The results of this investigation are of key
importance not only for understanding the nature of the X-ray emission
of the M87 jet, but also for understanding flares in blazar jets,
which are highly variable, but where we have never before been able to
resolve the flaring region in the optical or X-rays. These
observations will allow us to test synchrotron emission models for the
X-ray outburst, constrain particle acceleration and loss timescales,
and study the jet dynamics associated with this flaring component.

ACS/HRC/WFC 9728

Tracing the History of Cosmic Expansion to z~2 with Type Ia Supernovae

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating universe, an extraordinary result that needs the most
rigorous test. The case for cosmic acceleration rests on the
observation that SNe Ia at z = 0.5 are about 0.25 mag fainter than
they would be in a universe without acceleration. A powerful and
straightforward way to assess the reliability of the SN Ia measurement
and the conceptual framework of its interpretation is to look for
cosmic deceleration at z 1. This would be a clear signature of a
mixed dark-matter and dark-energy universe. Systematic errors in the
SNe Ia result attributed to grey dust or cosmic evolution of the SN Ia
peak luminosity would not show this change of sign. We have obtained a
toehold on this putative ``epoch of deceleration'' with SN 1997ff at z
= 1.7, and 3 more at z 1 from our Cycle 11 program, all found and
followed by HST. However, this is too important a test to rest on just
a few objects, anyone of which could be subject to a lensed
line-of-sight or misidentification. Here we propose to extend our
measurement with observations of twelve SNe Ia in the range 1.0 z
1.5 or 6 such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be
discovered as a byproduct from proposed Treasury and DD programs.
These objects will provide a much firmer foundation for a conclusion
that touches on important questions of fundamental physics.

NIC2 9726

A NICMOS search for obscured supernovae in starburst galaxies

Recent near-IR monitoring campaigns were successful in detecting
obscured supernovae {SNe} in starburst galaxies. The inferred SN rate
is much higher than that obtained in previous optical campaigns, but
it is still significantly lower than expected by the high level star
formation of these systems. One possible explanation for the shortage
of SNe is that most of them occur in the nuclear region, where the
limited angular resolution of groundbased observations prevents their
detection. We propose NICMOS SNAP observations of a sample of
starburst galaxies already observed once by NICMOS, with the goal of
exploiting its sensitivity and angular resolution to detect nuclear
obscured SNe which might have been missed by groundbased surveys.
These observation will allow to assess the real SN rate in starbust
galaxies and deliver a sample of SN occurring in the extreme
environment of galactic nuclei. We expect to detect more than 55 SNe
{if the whole sample is observed}. If the number of SNe detected in
the program is much lower than expected it would prompt for a revision
of our understanding of the relation between the star formation rate
and the SN rate.

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.

ACS/WFC/NIC3 10340

PANS

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating universe, an extraordinary result that needs the most
rigorous test. The case for cosmic acceleration rests on the
observation that SNe Ia at z = 0.5 are about 0.25 mag fainter than
they would be in a universe without acceleration. A powerful and
straightforward way to assess the reliability of the SN Ia measurement
and the conceptual framework of its interpretation is to look for
cosmic deceleration at z 1. This would be a clear signature of a
mixed dark-matter and dark-energy universe. Systematic errors in the
SNe Ia result attributed to grey dust or cosmic evolution of the SN Ia
peak luminosity would not show this change of sign. We have obtained a
toehold on this putative ``epoch of deceleration'' with SN 1997ff at z
= 1.7, and 3 more at z 1 from our Cycle 11 program, all found and
followed by HST. However, this is too important a test to rest on just
a few objects, anyone of which could be subject to a lensed
line-of-sight or misidentification. Here we propose to extend our
measurement with observations of twelve SNe Ia in the range 1.0 z
1.5 or 6 such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be
discovered as a byproduct from proposed Treasury and DD programs.
These objects will provide a much firmer foundation for a conclusion
that touches on important questions of fundamental physics.

ACS/WFC 10257

Astrometric and Photometric Study of NGC 6397 for Internal Motions,
Dark Binaries, and X-Ray Sources

We propose to observe the central regions of the globular cluster NGC
6397 with ACS/WFC once per month for the 10 months of its visibility
in Cycle 13. The project has three main goals: {1} Measure internal
motions for roughly 3000 stars within 150 arcseconds of the cluster
center, using archival WFPC2 as a first epoch. The motion of the
typical star will be measured to 10-20%. We will detect any central
black hole {BH} with a mass greater than 1000 solar masses, and will
also measure core-collapse signatures such as anisotropy. {2} Conduct
the first-ever search for heavy binaries by looking for the
astrometric "wobble" of the luminous secondary. We should find all
heavy binaries in the field with separations between 1 and 5 AU and
periods between 3 months and 5 years. {3} Search for optical
counterparts to X-ray sources found by Chandra.

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.

NIC2 10228

Multi-color HST imaging of the GJ 803 debris disk

We propose to conduct a comprehensive high angular resolution study of
the newly discovered debris disk around GJ 803. This nearby, young
star has an estimated age of 8-20 Myr, a critical epoch in disk
evolution and planet formation. By virtue of its proximity {10 pc} and
nearly edge-on orientation, GJ 803's disk has an exceptional surface
brightness and angular size relative to other disks resolved in
scattered light thus far. Hence, this system offers an exciting new
opportunity to study debris disks. Our proposed ACS and NICMOS imaging
will elucidate the disk morphology, ascertain the grain properties as
a function of radius, and search for fine dynamical structure
indicative of the presence of planets. ACS WFC and NICMOS
coronagraphic imaging will explore the inner disk, which includes the
~17 AU inner disk hole inferred from the star's spectral energy
distribution. Complementary ACS WFC imaging will probe the outer disk
{70 AU}; at such large distances around GJ 803, dust evolutionary
timescales are longer than the stellar age, and hence we can study the
composition of primordial circumstellar material. The combined dataset
will provide the most comprehensive study to date of a debris disk
from ~7 AU to ~200 AU radius.

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
0.7z1.9, which provides an excellent measure of current star
formation rate. We will also detect star-forming and active galaxies
in other redshift ranges using other emission lines. The grism
observations will produce by far the best available Halpha luminosity
functions over the crucial--but poorly observed--redshift range where
galaxies appear to have assembled most of their stellar mass. This key
process of galaxy evolution needs to be studied with IR data; we found
that observations at shorter wavelengths appear to have missed a large
fraction of the star-formation in galaxies, due to dust reddening. We
will also obtain deep F110W and F160W images, to examine the space
densities and morphologies of faint red galaxies. In addition to
carrying out the public parallels, we will make the fully reduced and
calibrated images and spectra available on-line, with some
ground-based data for the deepest parallel fields included.

STIS/CCD 10222

The Next Generation Spectral Library

We propose to complete our snapshot program to produce a Next
Generation Spectral Library of 600 stars for use in modeling the
integrated light of galaxies and clusters. This program is using the
low dispersion UV and optical gratings of STIS. The library will be
roughly equally divided among four metallicities, very low {[Fe/H]
-1.5}, low {-1.5 [Fe/H] -0.5}, near-solar {-0.3 [Fe/H] 0.1},
and super-solar {[Fe/H] 0.2}, well-sampling the entire HR-diagram in
each bin. Such a library will surpass all extant compilations and have
lasting archival value, well into the Next Generation Space Telescope
era. Because of the universal utility and community-broad nature of
this venture, we waive the entire proprietary period.

ACS/WFC 10210

Groups of Dwarf Galaxies: Pools of Mostly Dark Matter?

Within 5 Mpc, there are 6 groups with well-known luminous galaxies but
there also appears to be a comparable number of groups containing only
dwarfs. If these dwarf entities are truly bound then M/L values are an
order of magnitude higher than values found for groups with luminous
spiral galaxies. There are theoretical reasons to anticipate that low
mass halos may frequently be mostly dark. The dynamical influence of
low mass halos is negligible in familiar groups with luminous members.
By contrast, a study of the dynamics of `groups of dwarfs' may provide
direct evidence of the existence of dark matter potential wells with
few baryons. The goal of the present study is to gather detailed
information on the 3-D distribution of dwarf galaxies suspected to lie
within 7 groups of dwarfs within 5 Mpc. Distances with 7% relative
accuracy can be measured with the Tip of the Giant Branch method with
ACS and integrations within 1 orbit per target.

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.

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
quasars.

ACS/WFC 10120

The Formation Histories and Dynamical Roles of X-ray Binaries in
Globular Clusters

Close binaries are fundamental to the dynamical stability and
evolution of globular clusters, but large populations have been
extremely difficult to identify. Chandra X-ray images provide a
revolutionary resource, revealing a few to dozens of low-luminosity
X-ray sources in every cluster deeply examined; our own Chandra
programs uniformly study these ubiquitous X-ray sources {close
binaries and their progeny} in 11 clusters. However, definitive
understanding of the nature of the various X-ray subpopulations
requires the identification of optical counterparts, and HST is the
demonstrated key in these crowded environments. We thus propose a
proven, efficient, and uniform, HST multicolor imaging program for
optical identifications in 6 of our clusters with Chandra data
on-hand, but which lack adequate optical images in the HST archive.
The proposed ACS images will permit statistical classifications into
the various subtypes: CVs, qLMXBs, BY Dra's/RS CVn's {and MSPs}. A
unique aspect of our program is that our clusters span a range of
physical properties such as central concentration, cluster size, and
mass--essential ingredients in the formation, evolution, and dynamical
roles of cluster binaries. Exploiting this range of properties, we
have identified a relation that provides the first compelling link
between the number of X-ray sources and the predicted stellar
encounter frequency in globular cluster cores. But further progress in
understanding the details implicit in this relationship {e.g., whether
CVs and qLMXBs formed primarily via stellar encounters, while BY
Dra's/RS CVn's are mainly primordial binaries} demands uniform optical
identifications for multiple clusters, spanning the full range
physical properties.

FGS 10110

Parallaxes of Extreme Halo Subgiants: Calibrating Globular Cluster
Distances and the Ages of the Oldest Stars

The ages of the oldest stars are a key constraint on the evolution of
our Galaxy, the history of star formation, and cosmological models.
These ages are usually determined from globular clusters. However, it
is alternatively possible to determine ages of extreme Population II
subgiants in the solar neighborhood based on trigonometric parallaxes,
without any recourse to clusters. This approach completely avoids the
vexing issues of cluster distances, reddenings, and chemical
compositions. There are 3 known nearby, extremely metal-deficient Pop
II subgiants with Hipparcos parallax errors of 6-11% which are
available for such age determinations. At present, based on the latest
isochrones, the derived ages of these stars {HD 84937, HD 132475, and
HD 140283} are all close to 14 Gyr, uncomfortably close to or higher
than current estimates of the age of the universe. However, the errors
in the Hipparcos parallaxes imply uncertainties of at least 2 Gyr in
the ages of the 3 stars. We propose to measure parallaxes of these
three Pop II subgiants using HST's Fine Guidance Sensor 1R. We expect
to reduce the Hipparcos parallax error bars by factors of 5-6,
providing the most stringent test yet of current theoretical stellar
models of Pop II stars and pushing the age uncertainties to below 0.5
Gyr. These data will also provide a major new constraint on the
distance scale of globular clusters, with wide implications for
stellar evolution and the calibration of Pop II standard candles.

FGS 10103

FGS Astrometry of a Star Hosting an Extrasolar Planet: The Mass of
Upsilon Andromedae d

We propose observations with HST/FGS to determine the astrometric
elements {perturbation orbit semimajor axis and inclination} produced
by the outermost extra-solar planet orbiting the F8V star Upsilon
Andromedae. These observations will permit us to determine the actual
mass of the planet by providing the presently unknown sin i factor
intrinsic to the radial velocity method which discovered this object.
An inclination, i = 30degrees, within the range of one very low
precision determination using reanalyzed HIPPARCOS intermediate data
products, would produce the observed radial velocity amplitude, K = 66
ms with a companion mass of ~8 M_Jupiter. Such a mass would induce in
Upsilon Andromedae a perturbation semi-major axis, Alpha = 0arcs0012,
easily within the reach of HST/FGS fringe tracking astrometry. The
proposed observations will yield a planetary mass, rather than, as
previous investigations have done, only suggest a planetary mass
companion.

ACS/WFC 10098

Probing the nature of Type Ia SNe through HST astrometry

Type Ia supernovae are of key importance in cosmology. Empirical
relations allow their use as cosmological standard candles. The
generally accepted picture is that the exploding star is a C+O white
dwarf which accretes matter from a companion in a binary system.
However, the nature of the companion is still unknown. It could either
be another WD, or be a giant, subgiant, or main-sequence star.
Calculations have shown that it is possible to distinguish among those
possibilities by the effect that the supernova explosion has on the
companion star. We propose to identify the companion star of the two
historical well-known SNeIa through ACS imaging of the targets
complemented by WFPC2 observations. A radial-velocity study of the
stars in those two Galactic SNeIa has been done from ground-based
facilities. To obtain the full motion vector of those stars, we plan
to use ACS for high-resolution astrometry in two different epochs.
That should allow to detect motion imparted during the explosion in
the direction perpendicular to the line of sight, down to a level of a
few milliarcsecs/yr.

WFPC2 10071

WFPC2 CYCLE 12 Supplemental Darks Part 3/3

This dark calibration program obtains 3 dark frames every day to
provide data for monitoring and characterizing the evolution of hot
pixels.

ACS/HRC/WFC 10061

CCD Daily Monitor

This program consists of basic tests to monitor, the read noise, the
development of hot pixels and test for any source of noise in ACS CCD
detectors. This programme will be executed once a day for the entire
lifetime of ACS.

ACS/HRC 10050

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 coronographic
monitoring is required to assess the changing position of the spots.

STIS/CCD 10020

CCD Bias Monitor - Part 2

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,
and 1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns.

STIS/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.) None

COMPLETED OPS REQs: None

OPS NOTES EXECUTED:
0900-1 COMMAND PROBLEM @ 213/18:36:26z
0916-0 Tabulation of Slew Attitude Error (Miss-distance) @ 215/0047z


SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 36 36
FGS REacq 13 13
FHST Update 49 49
LOSS of LOCK

SIGNIFICANT EVENTS: None


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Monitoring NASA Daily ISS Report JimO Space Station 2 June 1st 04 10:33 PM
JimO Speaks on 'Daily Planet' re Hubble JimO Policy 0 February 11th 04 11:53 PM
Spirit's daily activities schedule? Matti Anttila Policy 0 January 15th 04 09:39 AM
best site for daily schedule of rover activity? bob History 2 January 5th 04 01:16 PM
Investor's Business Daily: Rethinking NASA dougk Policy 1 August 28th 03 12:07 AM


All times are GMT +1. The time now is 04:21 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 SpaceBanter.com.
The comments are property of their posters.