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 Report #5150



 
 
Thread Tools Display Modes
  #1  
Old August 2nd 10, 04:30 PM posted to sci.astro.hubble
Cooper, Joe
external usenet poster
 
Posts: 568
Default Daily Report #5150

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #5150

PERIOD COVERED: 5am July 30 - 5am August 2, 2010 (DOY 211/09:00z-214/09:00z)

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

12344 - At 213/18:01:57z a COS Dump Timeout Error was received. The
timeout error occurred during the instrument dump to the SSR. This
error is received when the timeout alarm at the end of an instrument
dump has expired, meaning the dump did not complete in the expected
amount of time.

Observation possibly affected COS 212, proposal ID# 12086

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 15 15
FGS REAcq 31 31
OBAD with Maneuver 13 13

SIGNIFICANT EVENTS: (None)


OBSERVATIONS SCHEDULED:

COS/NUV/FUV 12086

Generation of 1-D Fixed Pattern Templates

Tests have shown that application of a 1-D fixed pattern template to a
COS spectrum can reduce the fixed pattern noise in G130M or G160M
spectra to an equivalent S/N of about 30/1. For this to be occur, the
template must be derived from data for the same grating and nearly the
same central wavelength as the observation. This is because each
grating has a different cross dispersion profile, and different
central wavelengths fall at different cross dispersion detector
locations. As a result, spectra obtained at each grating and central
wavelength setting are derived from different regions of the detectors
-- each with their own, unique detector features and grid wire
shadows.

S/C 12046

COS FUV DCE Memory Dump

Whenever the FUV detector high voltage is on, count rate and current
draw information is collected, monitored, and saved to DCE memory.
Every 10 msec the detector samples the currents from the HV power
supplies (HVIA, HVIB) and the AUX power supply (AUXI). The last 1000
samples are saved in memory, along with a histogram of the number of
occurrences of each current value.

In the case of a HV transient (known as a "crackle" on FUSE), where
one of these currents exceeds a preset threshold for a persistence
time, the HV will shut down, and the DCE memory will be dumped and
examined as part of the recovery procedure. However, if the current
exceeds the threshold for less than the persistence time (a
"mini-crackle" in FUSE parlance), there is no way to know without
dumping DCE memory. By dumping and examining the histograms regularly,
we will be able to monitor any changes in the rate of "mini-crackles"
and thus learn something about the state of the detector.

WFC3/UVIS 12018

Ultra-Luminous X-Ray Sources in the Most Metal-Poor Galaxies

There is growing observational and theoretical evidence to suggest
that Ultra-Luminous X-ray sources (ULX) form preferentially in low
metallicity environments. Here we propose a survey of 27 nearby (
30Mpc) star-forming Extremely Metal Poor Galaxies (Z5% solar). There
are almost no X-ray observations of such low abundance galaxies (3 in
the Chandra archive). These are the most metal-deficient galaxies
known, and a logical place to find ULX if they favor metal-poor
systems. We plan to test recent population synthesis models which
predict that ULX should be very numerous in metal-poor galaxies. We
will also test the hypothesis that ULX form in massive young star
clusters, and ask for HST time to obtain the necessary imaging data.

ACS/WFC 11996

CCD Daily Monitor (Part 3)

This program comprises basic tests for measuring the read noise and
dark current of the ACS WFC and for tracking the growth of hot pixels.
The recorded frames are used to create bias and dark reference images
for science data reduction and calibration. This program will be
executed four days per week (Mon, Wed, Fri, Sun) for the duration of
Cycle 17. To facilitate scheduling, this program is split into three
proposals. This proposal covers 308 orbits (19.25 weeks) from 21 June
2010 to 1 November 2010.

WFC3/IR/S/C 11929

IR Dark Current Monitor

Analyses of ground test data showed that dark current signals are more
reliably removed from science data using darks taken with the same
exposure sequences as the science data, than with a single dark
current image scaled by desired exposure time. Therefore, dark current
images must be collected using all sample sequences that will be used
in science observations. These observations will be used to monitor
changes in the dark current of the WFC3-IR channel on a day-to-day
basis, and to build calibration dark current ramps for each of the
sample sequences to be used by Gos in Cycle 17. For each sample
sequence/array size combination, a median ramp will be created and
delivered to the calibration database system (CDBS).

WFC3/UVIS 11924

WFC3/UVIS External and Internal CTE Monitor

CCD detector Charge Transfer Inefficiency (CTI)-induced losses in
photometry and astrometry will be measured using observations of the
rich open cluster NGC6791 and with the EPER (Extended Pixel Edge
Response) method using tungsten lamp flat field exposures. Although we
do not expect to see CTE effects at the outset of Cycle 17, this CTE
monitoring program is the first of a multi-cycle program to monitor
and establish CTE-induced losses with time. We expect to measure CTE
effects with a precision comparable to the ACS measurements.

WFC3/IR 11915

IR Internal Flat Fields

This program is the same as 11433 (SMOV) and depends on the completion
of the IR initial alignment (Program 11425). This version contains
three instances of 37 internal orbits: to be scheduled early, middle,
and near the end of Cycle 17, in order to use the entire 110-orbit
allocation.

In this test, we will study the stability and structure of the IR
channel flat field images through all filter elements in the WFC3-IR
channel. Flats will be monitored, i.e. to capture any temporal trends
in the flat fields and delta flats produced. High signal observations
will provide a map of the pixel-to-pixel flat field structure, as well
as identify the positions of any dust particles.

WFC3/UVIS 11908

Cycle 17: UVIS Bowtie Monitor

Ground testing revealed an intermittent hysteresis type effect in the
UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially found via an unexpected bowtie-shaped feature in flatfield
ratios, subsequent lab tests on similar e2v devices have since shown
that it is also present as simply an overall offset across the entire
CCD, i.e., a QE offset without any discernable pattern. These lab
tests have further revealed that overexposing the detector to count
levels several times full well fills the traps and effectively
neutralizes the bowtie. Each visit in this proposal acquires a set of
three 3x3 binned internal flatfields: the first unsaturated image will
be used to detect any bowtie, the second, highly exposed image will
neutralize the bowtie if it is present, and the final image will allow
for verification that the bowtie is gone.

WFC3/UVIS 11905

WFC3 UVIS CCD Daily Monitor

The behavior of the WFC3 UVIS CCD will be monitored daily with a set
of full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K
subarray biases are acquired at less frequent intervals throughout the
cycle to support subarray science observations. The internals from
this proposal, along with those from the anneal procedure (Proposal
11909), will be used to generate the necessary superbias and superdark
reference files for the calibration pipeline (CDBS).

WFC3/UV 11904

UVIS Droplets

To characterize the effects of the contamination (i.e., droplets) on
the UVIS window, we will observe a star cluster in three wide band
filters (F225W, F555W, and F814W) as well as a narrow band filter
(F502N) and step the stars in the cluster across randomly located
droplets. The step size is 20 pixels, and we execute a five point line
dither for each filter. This should provide for observations both on
and off the droplets, for the same star. Internal flat fields are also
obtained, but, due to the high f/# of the internal calibration system,
the flats will be of limited utility, but will serve to map and
crudely track any changes in the droplets. The cluster needs to
contain both hot and cool stars, and therefore we select NGC 6752, a
nearby globular with a hot horizontal branch. Note, although the total
population of HB stars may be larger in systems such as NGC 2419, NGC
6715, and NGC 2808, those clusters are much further away and will not
provide a high density of stars over the global image (the droplets
are located over the entire frame). There will be three visits
(initial, 7 days later, and 30 days later), with each visit requiring
4 orbits. The total program thus requires 12 orbits total.

COS/FUV 11897

FUV Spectroscopic Sensitivity Monitoring

The purpose of this proposal is to monitor sensitivity in each FUV
grating mode to detect any changes due to contamination or other
causes.

WFC3/ACS 11888

ACS Internal Flat Fields

The stability of the CCD flat fields will be monitored using the
calibration lamps and a sub-sample of the filter set. High signal
observations will be used to assess the stability of the
pixel-to-pixel flat field structure and to monitor the position of the
dust motes.

STIS/CC 11847

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/CC 11845

CCD Dark Monitor Part 2

Monitor the darks for the STIS CCD.

COS/NUV/FUV 11741

Probing Warm-Hot Intergalactic Gas at 0.5 z 1.3 with a Blind
Survey for O VI, Ne VIII, Mg X, and Si XII Absorption Systems

Currently we can only account for half of the baryons (or less)
expected to be found in the nearby universe based on D/H and CMB
observations. This "missing baryons problem" is one of the
highest-priority challenges in observational extragalatic astronomy.
Cosmological simulations suggest that the baryons are hidden in
low-density, shock-heated intergalactic gas in the log T = 5 - 7
range, but intensive UV and X-ray surveys using O VI, O VII, and O
VIII absorption lines have not yet confirmed this prediction. We
propose to use COS to carry out a sensitive survey for Ne VIII and Mg
X absorption in the spectra of nine QSOs at z(QSO) 0.89. For the
three highest-redshift QSOs, we will also search for Si XII. This
survey will provide more robust constraints on the quantity of baryons
in warm-hot intergalactic gas at 0.5 z 1.3, and the data will
provide rich constraints on the metal enrichment, physical conditions,
and nature of a wide variety of QSO absorbers in addition to the
warm-hot systems. By comparing the results to other surveys at lower
redshifts (with STIS, FUSE, and from the COS GTO programs), the
project will also enable the first study of how these absorbers evolve
with redshift at z 1. By combining the program with follow-up galaxy
redshift surveys, we will also push the study of galaxy-absorber
relationships to higher redshifts, with an emphasis on the
distribution of the WHIM with respect to the large-scale matter
distribution of the universe.

WFC3/UV/IR 11709

Stretching the Diversity of Cosmic Explosions: The Supernovae of
Gamma-ray Bursts

While the association between gamma-ray bursts (GRBs) and massive
stars is robust, there is a large diversity of properties among
supernovae (SNe) associated with GRBs. The converse is also true:
Several recent events show that there is a large brightness range
among high energy transients associated with SNe. As part of a
comprehensive program, we propose to use HST in order to search for
and characterize the SNe associated with GRB.

HST offers the means to cleanly separate the light curve of the GRB
afterglow from the supernova, and to remove the contamination from the
host galaxy, opening a clear path to the fundamental parameters of the
SN, and thence to the progenitor. From these observations, we will
determine the absolute magnitude at maximum, the shape of the spectral
energy distribution, and any change over time of the energy
distribution. We will also measure the rate of decay of the
exponential tail.

Merged with the ground-based data that we will obtain for each event,
we will be able to compare our data set to models and constrain the
energy of the explosion, the mass of the ejecta and the mass of Nickel
synthesized during the explosion. These results will shed light on the
apparent variety of supernovae associated with gamma-ray bursts and
X-ray flashes, and on the relation between these SNe and other, more
common, types of core-collapse explosions.

WFC3/UVIS/IR 11700

Bright Galaxies at z7.5 with a WFC3 Pure Parallel Survey

The epoch of reionization represents a special moment in the history
of the Universe as it is during this era that the first galaxies and
star clusters are formed. Reionization also profoundly affects the
environment where subsequent generations of galaxies evolve. Our
overarching goal is to test the hypothesis that galaxies are
responsible for reionizing neutral hydrogen. To do so we propose to
carry out a pure parallel WFC3 survey to constrain the bright end of
the redshift z7.5 galaxy luminosity function on a total area of 176
arcmin^2 of sky. Extrapolating the evolution of the luminosity
function from z~6, we expect to detect about 20 Lyman Break Galaxies
brighter than M_* at z~8 significantly improving the current sample of
only a few galaxies known at these redshifts. Finding significantly
fewer objects than predicted on the basis of extrapolation from z=6
would set strong limits to the brightness of M_*, highlighting a fast
evolution of the luminosity function with the possible implication
that galaxies alone cannot reionize the Universe. Our observations
will find the best candidates for spectroscopic confirmation, that is
bright z7.5 objects, which would be missed by small area deeper
surveys. The random pointing nature of the program is ideal to beat
cosmic variance, especially severe for luminous massive galaxies,
which are strongly clustered. In fact our survey geometry of 38
independent fields will constrain the luminosity function like a
contiguous single field survey with two times more area at the same
depth. Lyman Break Galaxies at z7.5 down to m_AB=26.85 (5 sigma) in
F125W will be selected as F098M dropouts, using three to five orbits
visits that include a total of four filters (F606W, F098M, F125W,
F160W) optimized to remove low-redshift interlopers and cool stars.
Our data will be highly complementary to a deep field search for high-
z galaxies aimed at probing the faint end of the luminosity function,
allowing us to disentangle the degeneracy between faint end slope and
M_* in a Schechter function fit of the luminosity function. We waive
proprietary rights for the data. In addition, we commit to release the
coordinates and properties of our z7.5 candidates within one month
from the acquisition of each field.

WFC3/IR 11696

Infrared Survey of Star Formation Across Cosmic Time

We propose to use the unique power of WFC3 slitless spectroscopy to
measure the evolution of cosmic star formation from the end of the
reionization epoch at z6 to the close of the galaxy- building era at
z~0.3.Pure parallel observations with the grisms have proven to be
efficient for identifying line emission from galaxies across a broad
range of redshifts. The G102 grism on WFC3 was designed to extend this
capability to search for Ly-alpha emission from the first galaxies.
Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will
observe about 40 deep (4-5 orbit) fields with the combination of G102
and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.

Our primary science goals at the highest redshifts a (1) Detect Lya
in ~100 galaxies with z5.6 and measure the evolution of the Lya
luminosity function, independent of of cosmic variance; 2) Determine
the connection between emission line selected and continuum-break
selected galaxies at these high redshifts, and 3) Search for the
proposed signature of neutral hydrogen absorption at re-ionization. At
intermediate redshifts we will (4) Detect more than 1000 galaxies in
Halpha at 0.5z1.8 to measure the evolution of the
extinction-corrected star formation density across the peak epoch of
star formation. This is over an order-of-magnitude improvement in the
current statistics, from the NICMOS Parallel grism survey. (5) Trace
``cosmic downsizing" from 0.5z2.2; and (6) Estimate the evolution in
reddening and metallicty in star- forming galaxies and measure the
evolution of the Seyfert population. For hundreds of spectra we will
be able to measure one or even two line pair ratios -- in particular,
the Balmer decrement and [OII]/[OIII] are sensitive to gas reddening
and metallicity. As a bonus, the G102 grism offers the possibility of
detecting Lya emission at z=7-8.8.

To identify single-line Lya emitters, we will exploit the wide
0.8--1.9um wavelength coverage of the combined G102+G141 spectra. All
[OII] and [OIII] interlopers detected in G102 will be reliably
separated from true LAEs by the detection of at least one strong line
in the G141 spectrum, without the need for any ancillary data. We
waive all proprietary rights to our data and will make high-level data
products available through the ST/ECF.

COS/NUV/FUV/STIS/CCD/ 11692 MA1 The LMC as a QSO Absorption Line
System

We propose to obtain high resolution, high signal-to-noise
observations of QSOs behind the Large Magellanic Clouds. These QSOs
are situated beyond the star forming disk of the galaxy, giving us the
opportunity to study the distribution of metals and energy in regions
lacking significant star formation. In particular, we will derive the
metallicities and study the ionization characteristics of LMC gas at
impact parameters 3-17 kpc. We will compare our results with high-z
QSO absorption line systems.

ACS/WFC/WFC3/UV/IR 11691

Using Massive Star Clusters in Merger Remnants To Provide Reference
Colors of Intermediate- Age Stellar Populations

Much current research in cosmology and galaxy formation relies on an
accurate interpretation of colors of galaxies in terms of their
evolutionary state, i.e., in terms of ages and metallicities. One
particularly important topic is the ability to identify early-type
galaxies at "intermediate" ages (~ 500 Myr - 5 Gyr), i.e., the period
between the end of star formation and ~ half the age of the universe.
Currently, integrated-light studies must rely on population synthesis
models which rest upon spectral libraries of stars in the solar
neighborhood. These models have a difficult time correctly
incorporating short-lived evolutionary phases such as thermally
pulsing AGB stars, which produce up to 80% of the flux in the near-IR
in this age range. Furthermore, intermediate-age star clusters in the
Local Group do not represent proper templates against which to
calibrate population synthesis models in this age range, because their
masses are too low to render the effect of stochastic fluctuations due
to the number of bright RGB and AGB stars negligible. As a
consequence, current population synthesis models have trouble
reconciling the evolutionary state of high-redshift galaxies from
optical versus near-IR colors. We propose a simple and effective
solution to this issue, namely obtaining high-quality EMPIRICAL colors
of massive globular clusters in galaxy merger remnants which span this
important age range. These colors should serve as relevant references,
both to identify intermediate-age objects in the local and distant
universe and as calibrators for population synthesis modellers.

WFC3/UVIS 11675

Stellar Forensics: A Post-Explosion View of the Progenitors of
Core-Collapse Supernovae

Recent studies have used high spatial resolution HST observations of
SN sites to identify the progenitors of core-collapse SNe on
pre-explosion images. These studies have set constraints about the
nature of massive stars and their evolution just prior to their
explosion as SNe. Now, at late-times when the SNe have faded
sufficiently, it is possible to return to the sites of these
core-collapse SNe to search for clues about the nature of their
progenitors. We request time to conduct deep, late-time,
high-resolution imaging with ACS/HRC of the sites of six core-collapse
SNe. In this program we aim to: 1) confirm our identifications, that
were made with HST pre- explosion images, of the red supergiant
progenitors of four Type IIP SNe (1999ev, 2003gd, 2004A and 2005cs),
by observing if the objects identified as the progenitors are now
missing; 2) place precise constraints on the progenitor of the Type Ic
SN 2007gr by studying its host cluster; and 3) confirm our
identification of an LBV-like outburst of an unstable WR star as
belonging to the progenitor of a Type Ib-n core-collapse SN (2006jc),
using broad and narrow- band imaging to search for emission line stars
in its locality. The deep imaging will also allow to probe the stellar
populations in the immediate vicinities of these SNe, that were
previously obscured by the progenitors and the bright SNe. HST
provides the unique combination of high- resolution optical imaging at
very faint magnitudes that will facilitate this study.

COS/NUV/FUV 11598

How Galaxies Acquire their Gas: A Map of Multiphase Accretion and
Feedback in Gaseous Galaxy Halos

We propose to address two of the biggest open questions in galaxy
formation - how galaxies acquire their gas and how they return it to
the IGM - with a concentrated COS survey of diffuse multiphase gas in
the halos of SDSS galaxies at z = 0.15 - 0.35. Our chief science goal
is to establish a basic set of observational facts about the physical
state, metallicity, and kinematics of halo gas, including the sky
covering fraction of hot and cold material, the metallicity of infall
and outflow, and correlations with galaxy stellar mass, type, and
color - all as a function of impact parameter from 10 - 150 kpc.
Theory suggests that the bimodality of galaxy colors, the shape of the
luminosity function, and the mass-metallicity relation are all
influenced at a fundamental level by accretion and feedback, yet these
gas processes are poorly understood and cannot be predicted robustly
from first principles. We lack even a basic observational assessment
of the multiphase gaseous content of galaxy halos on 100 kpc scales,
and we do not know how these processes vary with galaxy properties.
This ignorance is presently one of the key impediments to
understanding galaxy formation in general. We propose to use the
high-resolution gratings G130M and G160M on the Cosmic Origins
Spectrograph to obtain sensitive column density measurements of a
comprehensive suite of multiphase ions in the spectra of 43 z 1 QSOs
lying behind 43 galaxies selected from the Sloan Digital Sky Survey.
In aggregate, these sightlines will constitute a statistically sound
map of the physical state and metallicity of gaseous halos, and
subsets of the data with cuts on galaxy mass, color, and SFR will seek
out predicted variations of gas properties with galaxy properties. Our
interpretation of these data will be aided by state-of-the-art
hydrodynamic simulations of accretion and feedback, in turn providing
information to refine and test such models. We will also use Keck,
MMT, and Magellan (as needed) to obtain optical spectra of the QSOs to
measure cold gas with Mg II, and optical spectra of the galaxies to
measure SFRs and to look for outflows. In addition to our other
science goals, these observations will help place the Milky Way's
population of multiphase, accreting High Velocity Clouds (HVCs) into a
global context by identifying analogous structures around other
galaxies. Our program is designed to make optimal use of the unique
capabilities of COS to address our science goals and also generate a
rich dataset of other absorption-line systems.

WFC3/UVIS 11588

Galaxy-Scale Strong Lenses from the CFHTLS Survey

We aim to investigate the origin and evolution of early-type galaxies
using gravitational lensing, modeling the mass profiles of objects
over a wide range of redshifts. The low redshift (z = 0.2) sample is
already in place following the successful HST SLACS survey; we now
propose to build up and analyze a sample of comparable size (~50
systems) at high redshift (0.4 z 0.9) using HST WFC3 Snapshot
observations of lens systems identified by the SL2S collaboration in
the CFHT legacy survey.

NIC2/WFC3/IR 11548

Infrared Imaging of Protostars in the Orion A Cloud: The Role of
Environment in Star Formation

We propose NICMOS and WFC3/IR observations of a sample of 252
protostars identified in the Orion A cloud with the Spitzer Space
Telescope. These observations will image the scattered light escaping
the protostellar envelopes, providing information on the shapes of
outflow cavities, the inclinations of the protostars, and the overall
morphologies of the envelopes. In addition, we ask for Spitzer time to
obtain 55-95 micron spectra of 75 of the protostars. Combining these
new data with existing 3.6 to 70 micron photometry and forthcoming
5-40 micron spectra measured with the Spitzer Space Telescope, we will
determine the physical properties of the protostars such as envelope
density, luminosity, infall rate, and outflow cavity opening angle. By
examining how these properties vary with stellar density (i.e.
clusters vs. groups vs. isolation) and the properties of the
surrounding molecular cloud; we can directly measure how the
surrounding environment influences protostellar evolution, and
consequently, the formation of stars and planetary systems.
Ultimately, this data will guide the development of a theory of
protostellar evolution.

 




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
Daily Report Cooper, Joe Hubble 0 December 22nd 08 06:17 PM
Daily Report #4720 Cooper, Joe Hubble 0 October 21st 08 03:02 PM
Daily Report #4287 Lynn Bassford Hubble 0 January 29th 07 10:36 PM
Daily Report [email protected] Hubble 0 October 29th 04 04:59 PM
HST Daily Report 131 George Barbehenn Hubble 0 May 11th 04 02:48 PM


All times are GMT +1. The time now is 10:14 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.