NASA Hubble Space Telescope Daily Status Report # 3562
HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science
DAILY REPORT # 3562
PERIOD COVERED: DOY 61
OBSERVATIONS SCHEDULED
ACS 9352
The Deceleration Test from Treasury Type Ia Supernovae at Redshifts
1.2 to 1.6
Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating universe, an extraordinary result that needs a rigorous
test. The case for cosmic acceleration rests on the observation that
SNe Ia at z ~ 0.5 are ~ 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 SN Ia result attributed
to grey dust or cosmic evolution of the SN Ia peak luminosity would
not show this change of sign. We have demonstrated proof of this
concept with a single SN Ia, SN 1997ff at z = 1.7, found and followed
by HST. The results suggest an early epoch of deceleration, but this
is too important a conclusion to rest on just one object. Here we
propose to use HST for observations of six SNe Ia in the range 1.2 <=
z <= 1.6, that will be discovered as a byproduct from proposed
Treasury programs for high-latitude ACS surveys. Six objects will
provide a much firmer foundation for a conclusion that touches on
important questions of fundamental physics.
ACS 9482
ACS Pure Parallel Lyman-Alpha Emission Survey {APPLES}
Ly-alpha line emission is an efficient tool for identifying young
galaxies at high redshift, because it is strong in galaxies with young
stars and little or no dust — properties expected in galaxies
undergoing their first burst of star- formation. Slitless spectroscopy
with the ACS Wide-Field Camera and G800L grism allows an unmatched
search efficiency for such objects over the uninterrupted range 4 <~ z
<~ 7. We propose the ACS Pure Parallel Ly-alpha Emission Survey
{“APPLES”}, to exploit this unique HST capability and so obtain the
largest and most uniform sample of high redshift Ly-alpha emitters
yet. Parallel observations will allow this survey to be conducted with
minimal impact on HST resources, and we will place reduced images and
extracted spectra in the public domain within three months of
observation. We aim to find ~ 1000 Ly-alpha emitters, 5 times the
biggest current sample of Ly-alpha emitters. This unprecedented
sample will provide robust statistics on the populations and evolution
of Ly-alpha emitters between redshifts 4–7; a robust measurement of
the reionization redshift completely independent of the Gunn-Peterson
trough; spatial clustering information for Ly-alpha emitters which
would let us probe their bias function and hence halo mass as a
function of redshift; many galaxies at redshift exceeding 6; and lower
redshift serendipitous discoveries.
ACS 9799
A Snapshot Survey of Galactic Bulge Globular Clusters
The globular clusters toward the Galactic bulge remain among the least
studied of the Galaxy’s globular clusters, primarily because severe
photometric crowding has hindered ground-based imaging. We propose a
snapshot survey {3 month proprietary period} using ACS onboard HST to
produce a complete sample of color-magnitude diagrams for these
clusters. The high spatial resolution of HST gives photometry vastly
superior to even the best ground-based color-magnitude diagrams.
Measurement of the horizontal and red giant branches gives reddening
and distance, from which physical parameters for the clusters are
derived. Ages to be derived are of special interest because this
population may contain the oldest clusters in the Galaxy.
Additionally, the separation of cluster members from contaminating
field stars will give far superior structural parameters than can be
derived from the ground. Many of these clusters have especially
concentrated cores; due to their proximity to the Galactic Center,
they may have experienced far greater dynamical evolution due to bulge
shocking. If stellar encounters are capable of modifying stellar
populations, these clusters probably are the best place to look for
such effects. Because ground-based study of these clusters has been so
difficult, we believe that this survey is potentially an important
part of HST’s legacy.
ACS 9984
Cosmic Shear With ACS Pure Parallels
Small distortions in the shapes of background galaxies by foreground
mass provide a powerful method of directly measuring the amount and
distribution of dark matter. Several groups have recently detected
this weak lensing by large-scale structure, also called cosmic shear.
The high resolution and sensitivity of HST/ACS provide a unique
opportunity to measure cosmic shear accurately on small scales. Using
260 parallel orbits in Sloan textiti {F775W} we will measure for the
first time: beginlistosetlength sep0cm setlengthemsep0cm setlength
opsep0cm em the cosmic shear variance on scales <0.7 arcmin, em the
skewness of the shear distribution, and em the magnification effect.
endlist Our measurements will determine the amplitude of the mass
power spectrum sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20,
and the mass density Omega_m with s/n=4. They will be done at small
angular scales where non-linear effects dominate the power spectrum,
providing a test of the gravitational instability paradigm for
structure formation. Measurements on these scales are not possible
from the ground, because of the systematic effects induced by PSF
smearing from seeing. Having many independent lines of sight reduces
the uncertainty due to cosmic variance, making parallel observations
ideal.
ACS/HRC/WFC 10059
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/WFC 9781
Galaxy Evolution in Action : The Detailed Morphology of Post-Starburst
Galaxy
If galaxies evolve morphologically, then some should be in transition
between late and early types. One proposed evolutionary mechanism is a
galaxy-galaxy merger, but evolved merger products are difficult to
find. Fortunately, spectroscopic surveys have now uncovered large
numbers of E+A galaxies, a class of objects whose post-starburst
spectra, current lack of HI gas, and pressure-supported kinematics
suggest that they are the missing panel that connects the "Toomre
sequence" of merging spirals with normal ellipticals and S0s. Our
first HST observations of five of these galaxies are intriguing. We
find a considerable range of tidally disturbed morphologies, an "E+A"
fundamental plane, significant differences among the color gradients
within 1 kpc {~0.8”}, and populations of bright, blue globular
clusters. These initial results are difficult to interpret, however,
because they are drawn from a small sample of galaxies whose very blue
overall colors may have selected a particular evolutionary path of
E+As. Here we propose for ACS imaging of the remaining 15 E+As from
the Las Campanas Redshift Survey to probe the full range of E+A
properties. The proposed observations will allow us to 1} determine
what fraction of the interactions that lead to E+As destroy all
disk-like structures {and therefore necessarily lead to elliptical
formation}, 2} measure the inner color gradients and constrain the
spatial distribution of stars produced as gas sinks to the center
during a merger, and 3} determine whether these interactions produce
globular clusters in the required numbers to account for the increased
specific frequency of clusters in early-type galaxies.
ACS/WFC 10006
Black Hole X-ray Novae in M31
During A01-3 we found 22 Black Hole X-ray Novae {BHXN} in M31 using
Chandra, and with HST {WFPC2} found two optical counterparts. Our
results suggest either a surprisingly high ratio of BH to NS binaries,
or a surprisingly high duty cycle for BHXN. We propose to continue
this program, with the goals of understanding the relative number of
BH vs. NS X-ray binaries in the M31 bulge, and determining the orbital
period distribution and duty cycles of these BHXN. Continued
observations can determine the duty cycle. The new ACS will allow us
to go 2 mags deeper than the WFPC2, and could triple the number of
optical counterparts and therefore orbital period estimates. M31 is
the only galaxy near enough to allow this extragalactic survey for
BHXN.
ACS/WFC 10049
ACS Internal Flat Field Stability
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. Shorter exposures will be used to identify charge traps and to
assess the stability of the DQ arrays. Only internal exposures with
the calibration lamps will be required.
ACS/WFC 9788
A Narrow-band Snapshot Survey of Nearby Galaxies
We propose to use ACS/WFC to conduct the first comprehensive HST
narrow-band {H-alpha + [N II]} imaging survey of the central regions
of nearby bulge-dominated disk {S0 to Sbc} galaxies. This survey will
cover, at high angular resolution extending over a large field, an
unprecedented number of galaxies representing many different
environments. It will have important applications for many
astrophysical problems of current interest, and it will be an
invaluable addition to the HST legacy. The observations will be
conducted in snapshot mode, drawing targets from a complete sample of
145 galaxies selected from the Palomar spectroscopic survey of nearby
galaxies. Our group will use the data for two primary applications.
First, we will search for nuclear emission-line disks suitable for
future kinematic measurements with STIS, in order to better constrain
the recently discovered relations between black hole mass and bulge
properties. Preliminary imaging of the type proposed here must be
done, sooner or later, if we are to make progress in this exciting new
field. Second, we will investigate a number of issues related to
extragalactic star formation. Specifically, we will systematically
characterize the properties of H II regions and super star clusters on
all galactic scales, from circumnuclear regions to the large-scale
disk.
FGS 9883
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.
NIC/NIC3 9865
The NICMOS Parallel Observing Program
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
0.7<z<1.9, 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.
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.
NIC2 9904
Lightning on the Jovian Dayside
The presence of lightning on Jupiter has been known for many years. It
represents an important diagnostic of atmospheric characteristics
below the visible cloud tops, within the water layer at a pressure ~5
bar or more. Lightning on Jupiter is thought to be associated with
convective water clouds, as on Earth, at cyclonic wind shear
interfaces. Dayside detection, which would enable "routine" access to
this important phenomenon, has never previously been achieved. Here,
we propose an innovative use of the NICMOS MULTIACCUM rapid
non-destructive readout capability, together with the very high
spatial resolution afforded by NIC2 {0.075 arcsec/pixel, 250 km at
Jupiter} to maximize our ability to detect and characterize Jovian
lightning on the dayside of the planet. We propose two complementary
observations: one to use the narrow filter centered on Paschen Alpha
and the other, to use a medium band continuum filter that avoids
methane absorption. By comparing these two passbands we expect to not
only detect dayside lightning for the first time, but also obtain the
first data on the spectrum of Jovian lightning at implicitly high
spectral resolution {the F187N filter has 1% bandpass, which also
further improves the contrast against reflected Solar light}. This
will allow us to test laboratory analogues and models for the Jovian
lightning and assess in a preliminary way the region of parameter
space of relevance {pressure, temperature, composition}.
NIC3 9735
ACS, NICMOS, and STIS Observations of Three Ongoing Mergers
We propose to make ACS {U, B, V, I, H_alpha}, NICMOS {J, H, K}, and
STIS {long-slit H_alpha} observations of NGC 520, NGC 2623, and NGC
3256, three merging galaxies in the middle of the Toomre Sequence and
currently in the throes of violent relaxation. Two of these {NGC 2623
and NGC 3256} are the most IR luminous galaxies in the sequence.
Hence, these ongoing mergers are ideal candidates for studying the
triggering mechanism responsible for the formation of stars and star
clusters. The ACS observations will allow us to age date the star
clusters, and reliably distinguish clusters from stars based on their
apparent sizes. They will also be used in conjunction with
ground-based measurements of the stellar velocity dispersion to
determine dynamical masses of the clusters and hence address the
question of whether the IMF is truncated. The NICMOS observations will
allow us to penetrate the dust and answer several fundamental
questions such as: What fraction of the young clusters are hidden by
dust? How do these clusters form and evolve? The STIS observations
will allow us to study the kinematics of the young cluster system and
measure the pressure and shock properties which may be triggering the
formation of the clusters. A better understanding of how mergers form
tremendous numbers of clusters and stars in the local universe will
help shed light on processes that were crucial during galaxy assembly
in the high-z universe.
NICMOS 8791
NICMOS Post-SAA calibration – CR Persistence Part 2
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.
STIS 9633
STIS parallel archive proposal – Nearby Galaxies – Imaging and
Spectroscopy
Using parallel opportunities with STIS which were not allocated by the
TAC, we propose to obtain deep STIS imagery with both the Clear
{50CCD} and Long-Pass {F28X50LP} filters in order to make
color-magnitude diagrams and luminosity functions for nearby galaxies.
For local group galaxies, we also include G750L slitless spectroscopy
to search for e.g., Carbon stars, late M giants and S-type stars. This
survey will be useful to study the star formation histories, chemical
evolution, and distances to these galaxies. These data will be placed
immediately into the Hubble Data Archive.
STIS/CCD 10017
CCD Dark Monitor-Part 1
Monitor the darks for the STIS CCD.
STIS/CCD 10019
CCD Bias Monitor – Part 1
Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1,
and 1×1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns.
STIS/CCD 10021
CCD Read Noise Monitor
This proposal measures the read noise of all the amplifiers {A, B, C,
D} on the STIS CCD using pairs of bias frames. Full frame and binned
observations are made in both Gain 1 and Gain 4, with binning factors
of 1×1, 1×2, 2×1 and 2×2. All exposures are internals. Pairs of visits
are scheduled for bimonthly execution.
STIS/CCD 10085
STIS Pure Parallel Imaging Program: Cycle 12
This is the default archival pure parallel program for STIS during
cycle 12.
STIS/MA1 10034
Cycle 12 MAMA Dark Monitor
This test performs the routine monitoring of the MAMA detector dark
noise. This proposal will provide the primary means of checking on
health of the MAMA detectors systems through frequent monitoring of
the background count rate. The purpose is to look for evidence of
change in dark indicative of detector problem developing.
STIS/MA1 9790
Separating Activity and Accretion in T Tauri Stars
Due to their unique evolutionary state, the naked {non-accreting} T
Tauri stars {NTTS} are the only real proxies for what the underlying
magnetically active star of a classical TTS {CTTS} system looks like.
Comparative analysis then allows us to separate stellar properties
from accretion properties in CTTS. In addition, the late-type NTTS are
excellent candidates for studying rotation-activity relationships in
fully convective stars and probing the properties of turbulent
dynamos. With the limited data currently available, NTTS appear to be
very magnetically active stars with higher than expected H-alpha/X-ray
flux ratios but lower transition region fluxes relative to other
active stars. However, the data are very incomplete. We will use
HST-STIS observations of transition region line fluxes on 11 fully
convective NTTS to establish the level and structure of dynamo
generated emission in these young stars. In principal, these far
ultraviolet emission lines are sensitive diagnostics of mass accretion
onto CTTS, since accretion shocks on the stellar surface should
produce substantial emission measure at 10^5 – 10^6 K. However, it is
imperative that we first understand the emissions from NTTS before we
can use these lines to study accretion onto CTTS.
WFPC2 10068
WFPC2 CYCLE 12 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 10070
WFPC2 CYCLE 12 Supplemental Darks Part 2/3
This dark calibration program obtains 3 dark frames every day to
provide data for monitoring and characterizing the evolution of hot
pixels.
WFPC2 10073
Earth Flats
This proposal monitors flatfield stability. This proposal obtains
sequences of Earth streak flats to construct high quality flat fields
for the WFPC2 filter set. These flat fields will allow mapping of the
OTA illumination pattern and will be used in conjunction with previous
internal and external flats to generate new pipeline superflats. These
Earth flats will complement the Earth flat data obtained during cycles
4-11.
WFPC2 10074
WFPC2 Cycle 12 UV Earth Flats
Monitor flat field stability. This proposal obtains sequences of earth
streak flats to improve the quality of pipeline flat fields for the
WFPC2 UV filter set. These Earth flats will complement the UV earth
flat data obtained during cycles 8-11.
WFPC2 10084
WFII parallel archive proposal
This is the generic target version of the WFPC2 Archival Pure Parallel
program. The program will be used to take parallel images of random
areas of the sky, following the recommendations of the 2002 Parallels
Working Group.
WFPC2 10090
WFII backup parallel archive proposal
This is a POMS test proposal designed to simulate scientific plans.
WFPC2 9712
Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS
Survey Fields
In anticipation of the allocation of ACS high-latitude imaging
survey{s}, we request a modification of the default pure parallel
program for those WFPC2 parallels that fall within the ACS survey
field. Rather than duplicate the red bands which will be done much
better with ACS, we propose to observe in the near-ultraviolet F300W
filter. These data will enable study of the rest-frame ultraviolet
morphology of galaxies at 0<z<1. We will determine the morphological
k-correction, and the location of star formation within galaxies,
using a sample that is likely to be nearly complete with
multi-wavelength photometry and spectroscopic redshifts. The results
can be used to interpret observations of higher redshift galaxies by
ACS.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)
SIGNIFICANT EVENTS: 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: None
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 13 13
FGS REacq 06 05 061/1038z
(HSTAR#9341)
FHST Update 22 22
LOSS of LOCK
SIGNIFICANT EVENTS:
FGS Transient Rate Test, 3rd Iteration scheduled 062/12:59:57Z –
13:30:00Z (SU 04974S1) and 062/14:26:33Z – 14:56:36Z (SU 04974S2).
