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 #4026



 
 
Thread Tools Display Modes
  #1  
Old January 12th 06, 02:39 PM posted to sci.astro.hubble
external usenet poster
 
Posts: n/a
Default Daily #4026

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4026

PERIOD COVERED: UT January 11, 2006 (DOY 011)

OBSERVATIONS SCHEDULED

ACS/HRC 10545

Icy planetoids of the outer solar system

Early HST studies of satellites of Kuiper belt object focussed on the
50-200 km objects that were the largest known at the time. In the past
3 years we have discovered a population of much more rare and much
larger {500-2000+ km} icy planetoids in the Kuiper belt. These objects
are the largest and brightest known in the Kuiper belt and, in the era
when we now know of more than 1000 Kuiper belt objects, these few
planetoids are likely to be the focus of much of the research on
physical properties of the outer solar system for years to come. We
are currently engaged in an intensive program involving Spitzer, Keck,
and other telescopes to study the physical and dynamical properties of
this new population. HST is uniquely capable of addressing one
parameter fundamental to completing the physical picture of these
planetoids: the existence and size of any satellites. The detection
and characterization of satellites to these large planetoids would
allow us to address unique issues critical to the formation and
evolution of the outer solar system, including the measurement of
densities, internal properties, sizes and shapes of these objects, the
study of binary formation as a function of primary size, and the
context of the Pluto-Charon binary. For these bright objects, a
satellite search takes less than a full orbit, allowing the
opportunity for a new project on UV spectroscopy of the planetoids to
piggyback at no added time cost. This poorly explored spectral range
has the potential to show unique signatures of trapped gasses,
cosmochemically important ices, and complex organic materials.

ACS/HRC 10556

Neutral Gas at Redshift z=0.5

Damped Lyman-alpha systems {DLAs} are used to track the bulk of the
neutral hydrogen gas in the Universe. Prior to HST UV spectroscopy,
they could only be studied from the ground at redshifts z1.65.
However, HST has now permitted us to discover 41 DLAs at z1.65 in our
previous surveys. Followup studies of these systems are providing a
wealth of information about the evolution of the neutral gas phase
component of the Universe. But one problem is that these 41
low-redshift systems are spread over a wide range of redshifts
spanning nearly 70% of the age of the Universe. Consequently, past
surveys for low-redshift DLAs have not been able to offer very good
precision in any small redshift regime. Here we propose an ACS-HRC-
PR200L spectroscopic survey in the redshift interval z=[0.37, 0.7]
which we estimate will permit us to discover another 41 DLAs. This
will not only allow us to double the number of low-redshift DLAs, but
it will also provide a relatively high-precision regime in the
low-redshift Universe that can be used to anchor evolutionary studies.
Fortunately DLAs have high absorption equivalent width, so
ACS-HRC-PR200L has high-enough resoultion to perform this proposed
MgII-selected DLA survey.

ACS/HRC/WFC 10514

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have
relatively fragile test particles which can be used as tracers of the
early dynamical evolution of the outer Solar System. We propose a
Snapshot program using the ACS/HRC that has a potential discovery
efficiency an order of magnitude higher than the HST observations that
have already discovered the majority of known transneptunian binaries.
By more than doubling the number of observed objects in dynamically
hot and cold subpopulations we will be able to answer, with
statistical significance, the question of whether these groups differ
in the abundance of binaries as a result of their particular dynamical
paths into the Kuiper Belt. Today's Kuiper Belt bears the imprints of
the final stages of giant-planet building and migration; binaries may
offer some of the best preserved evidence of that long-ago era.

ACS/HRC/WFC 10729

ACS CCDs daily monitor

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. Changes from cycle 13:- The default
gain for WFC is 2 e-/DN. As before bias frames will be collected for
both gain 1 and gain 2. Dark frames are acquired using the default
gain {2}. This program cover the period Oct, 2 2005- May, 29-2006. The
second half of the program has a different proposal number: 10758.

ACS/WFC 10543

Microlensing in M87 and the Virgo Cluster

Resolving the nature of dark matter is an urgent problem. The results
of the MACHO survey of the Milky Way dark halo toward the LMC indicate
that a significant fraction of the halo consists of stellar mass
objects. The VATT/Columbia survey of M31 finds a similar lens fraction
in the M31 dark halo. We propose a series of observations with ACS
that will provide the most thorough search for microlensing toward
M87, the central elliptical galaxy of the Virgo cluster. This program
is optimized for lenses in the mass range from 0.01 to 1.0 solar
masses. By comparing with archival data, we can detect lenses as
massive as 100 solar masses, such as the remnants of the first stars.
These observations will have at least 15 times more sensitivity to
microlensing than any previous survey, e.g. using WFPC2. This is due
to the factor of 2 larger area, factor of more than 4 more sensitivity
in the I-band, superior pixel scale and longer baseline of
observations. Based on the halo microlensing results in the Milky Way
and M31, we might expect that galaxy collisions and stripping would
populate the overall cluster halo with a large number of stellar mass
objects. This program would determine definitively if such objects
compose the cluster dark matter at the level seen in the Milky Way. A
negative result would indicate that such objects do not populate the
intracluster medium, and may indicate that galaxy harassment is not as
vigorous as expected. We can measure the level of events due to the
M87 halo: this would be the best exploration to date of such a lens
population in an elliptical galaxy. Star-star lensing should also be
detectable. About 20 erupting classical novae will be seen, allowing
to determine the definitive nova rate for this giant elliptical
galaxy. We will determine if our recent HST detection of an M87
globular cluster nova was a fluke, or indicative of a 100x higher rate
of incidence of cataclysmic variables and nova eruptions in globulars
than previously believed. We will examine the populations of variable
stars, and will be able to cleanly separate them from microlensing.

ACS/WFC 10592

An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in
the Local Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared
selected galaxies exceeds that of optically selected galaxies. These
`luminous infrared galaxies' {LIRGs} are primarily interacting or
merging disk galaxies undergoing enhanced star formation and Active
Galactic Nuclei {AGN} activity, possibly triggered as the objects
transform into massive S0 and elliptical merger remnants. We propose
ACS/WFC imaging of a complete sample of 88 L_IR 10^11.4 L_sun
luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample
{RBGS: i.e., 60 micron flux density 5.24 Jy}. This sample is ideal
not only in its completeness and sample size, but also in the
proximity and brightness of the galaxies. The superb sensitivity,
resolution, and field of view of ACS/WFC on HST enables a unique
opportunity to study the detailed structure of galaxies that sample
all stages of the merger process. Imaging will be done with the F439W
and F814W filters {B and I-band} to examine as a function of both
luminosity and merger state {i} the evidence at optical wavelengths of
star formation and AGN activity and the manner in which instabilities
{bars and bridges} in the galaxies may funnel material to these active
regions, {ii} the relationship between star formation and AGN
activity, and {iii} the structural properties {AGN, bulge, and disk
components} and fundamental parameters {effective radius and surface
brightness} of LIRGs and their similarity with putative evolutionary
byproducts {elliptical, S0 and classical AGN host galaxies}. This HST
survey will also bridge the wavelength gap between a Spitzer imaging
survey {covering seven bands in the 3.6-160 micron range} and a GALEX
UV imaging survey of these galaxies, but will resolve complexes of
star clusters and multiple nuclei at resolutions well beyond the
capabilities of either Spitzer or GALEX. The combined datasets will
result in the most comprehensive multiwavelength study of interacting
and merging galaxies to date.

ACS/WFC 10715

CSL-1: a peculiar gravitational lens and possible cosmic string

Much recent work {see for instance Huterer & Vachaspati 2003; Kibble
2004; Polchinski 2004} has emphasized the importance that the peculiar
object CSL-1 could bear on elementary particle physics and cosmology,
in the case that its nature as the first observational evidence for
lensing of a galaxy by a cosmic string could be confirmed. CSL-1 was
discovered by the proponents who also proposed several observational
tests to definitively pinpoint its nature {Sazhin et al. 2003, 2004}.
With this proposal we plan to carry the most important of such tests:
id est, to use the ACS/WFC to detect the sharp morphological features
produced by a cosmic string and to check whether the other
gravitational lens candidates, detected by the authors in the region
around CSL-1 on photometric grounds only {Sazhin et al. 2004}, present
similar peculiar features. Following Kibble {2004} and many others, we
wish to stress that, could its link to a cosmic string be confirmed,
CSL-1 will provide the first measurement ever of the energy scale of
the symmetry breaking and of the energy scale of the Grand Unification
Theory {GUT}, and will open a new way to investigate fundamental
physics using astronomical instruments.

FGS 10104

Calibrating the Mass-Luminosity Relation at the End of the Main
Sequence

We propose to use HST-FGS1R to calibrate the mass-luminosity relation
{MLR} for stars less massive than 0.2 Msun, with special emphasis on
objects near the stellar/brown dwarf border. Our goals are to
determine M_V values to 0.05 magnitude, masses to 5 than double the
number of objects with masses determined to be less than 0.20 Msun.
This program uses the combination of HST-FGS3/FGS1R at optical
wavelengths and ground-based infrared interferometry to examine
nearby, subarcsecond binary systems. The high precision measurements
with HST-FGS3/FGS1R {to 1 mas in the separations} for these faint
targets {V = 10--15} simply cannot be equaled by any ground based
technique. As a result of these measurements, we are deriving high
quality luminosities and masses for the components in the observed
systems, and characterizing their spectral energy distributions from
0.5 to 2.2 Mum. Several of the objects included have M 0.1 Msun,
placing them at the very end of the stellar main sequence. Three of
the targets are brown dwarf candidates, including the current low mass
record holder, GJ 1245C, with a mass of 0.062 +/- 0.004 Msun. The
payoff of this proposal is high because all 10 of the systems selected
have already been resolved with HST- FGS3/FGS1R during Cycles 5--10
and contain most of the reddest objects for which masses can be
determined.

NIC1/NC2/NC3 10723

Cycle 14 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 14. This proposal is a slightly modified version
of proposal 10380 of cycle 13 and 9993 of cycle12 that we cut down
some exposure time to make the observation fit within 24 orbits.

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.

WFPC2 10777

WFPC2 WF4 Bay 1 Temperature Reduction Test #1

A anomaly has been found in images from the WF4 CCD in WFPC2. The WF4
CCD bias level appears to have become unstable, resulting in sporadic
images with either low or zero bias level. The severity and frequency
of the problem is rapidly increasing, and it is possible that WF4 will
soon become unusable if no work-around is found. The other three CCDs
{PC1, WF2, and WF3} appear to be unaffected and continue to operate
properly. This proposal tests methods to fix the problem by adjusting
some temperatures inside WFPC2. 1 external and 24 internal orbits.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS: (None)

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 08 08
FGS REacq 06 06
OBAD with Maneuver 29 29

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
Judge Jones Has Been Reading the Wrong Books -- Intelligent Design vs. Evolution... Ed Conrad Amateur Astronomy 0 December 22nd 05 10:38 AM
FACTITIOUS THEORY LOSES AGAIN -- Evolution vs. Intelligent Design.... Ed Conrad Astronomy Misc 0 December 22nd 05 07:00 AM
BEST CHRISTMAS PRESENT OF THEM ALL . . . Ed Conrad Amateur Astronomy 10 December 21st 05 02:55 PM
THE BEST CHRISTMAS PRESENT OF ALL Ed Conrad Astronomy Misc 2 December 20th 05 03:31 AM
Ed Conrad's NEW Letter to Prof. Michael Behe Ed Conrad Astronomy Misc 0 June 21st 05 10:50 AM


All times are GMT +1. The time now is 11:43 AM.


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.