HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5027
PERIOD
COVERED: 5am February 4 - 5am February 5, 2010 (DOY 035/10:00z-036/10:00z)
OBSERVATIONS
SCHEDULED
COS/NUV
11894
NUV
Detector Dark Monitor
The
purpose of this proposal is to measure the NUV detector dark rate by
taking
long science exposures with no light on the detector. The
detector
dark rate and spatial distribution of counts will be compared
to
pre-launch and SMOV data in order to verify the nominal operation of
the
detector. Variations of count rate as a function of orbital position
will
be analyzed to find dependence of dark rate on proximity to the
SAA.
Dependence of dark rate as function of time will also be tracked.
COS/NUV
11896
NUV
Spectroscopic Sensitivity Monitoring
The
purpose of this proposal is to monitor sensitivity of each NUV
grating
mode to detect any changes due to contamination or other causes.
NIC3/WFC3/IR
11153
The
Physical Nature and Age of Lyman Alpha Galaxies
In
the simplest scenario, strong Lyman alpha emission from high redshift
galaxies
would indicate that stellar populations younger than 10 Myrs
dominate
the UV. This does not, however, constrain the stellar
populations
older than 100 Myrs, which do not contribute to UV light.
Also,
the Lyman alpha line can be boosted if the interstellar medium is
both
clumpy and dusty. Different studies with small samples have reached
different
conclusions about the presence of dust and old stellar
populations
in Lyman alpha emitters. We propose HST-NICMOS and
Spitzer-IRAC
photometry of 35 Lyman-alpha galaxies at redshift
4.5<z<6.5,
in order to determine their spectral energy distribution
(SED)
extending through rest-frame optical. This will allow us to
measure
accurately (1) The total stellar mass in these objects,
including
old stars which may have formed at redshifts (z > 8) not
easily
probed by any other means. (2) The dust extinction in the rest-
frame
UV, and therefore a correction to their present star-formation
rates.
Taken together, these two quantities will yield the
star-formation
histories of Lyman alpha galaxies, which form fully half
of
the known galaxies at z=4-6. They will tell us whether these are
young
or old galaxies by straddling the 4000A break. Data from NICMOS is
essential
for these compact and faint (i=25- 26th magnitude AB) high
redshift
galaxies, which are too faint for good near-IR photometry from
the
ground.
STIS/CC/MA
11516
COS-GTO:
Cold ISM
With
the COS, we will be able to observe interstellar spectra in a new
regime,
translucent clouds, for atomic, ionic, and molecular lines and
bands,
and extinction curves. The COS will allow us to observe stars
with
total visual extinctions up to 10 magnitudes, and the grain size
indicator
Rv up to 4.5. In translucent clouds we expect to see the
transition
from neutral and ionized carbon to mostly C I, and then from
there,
we should expect to see carbon increasingly locked up in
molecular
form, as CO. Other species are expected to make similar
transitions,
so we should find detectable abundances of molecules such
as
H2O, OH, CS, CH2, SiO, and others; also, lower ionization fractions
of
the metallic elements - and higher depletions of those elements as
well.
Given that we expect to find higher depletions, we should see an
altered
grain size distribution, which may show up in the extinction
curves,
probably as lower far-UV extinction than in diffuse clouds.
Finally,
we will search for neutral PAHs in absorption, as diffuse bands
in
the UV, paralleling the optical DIBs (which are thought by some
scientists
to be formed by singly-ionized PAHs). In translucent clouds,
models
show that the PAHs will be neutral, not in cationic form.
STIS/CC/MA
11608
How
Far Does H2 Go: Constraining FUV Variability in the Gaseous Inner
Holes
of Protoplanetary Disks
By
studying the innermost, planet-forming regions of circumstellar disks
around
low-mass pre-main sequence stars we can refine theories of planet
formation
and develop timescales for the evolution of disks and their
planets.
Spitzer infrared observations of T Tauri stars have given us an
unprecedented
look at dust evolution in young objects, particularly the
transitional
disks. However, despite this ground breaking progress in
studying
the dust in young disks, the relationship between the dust and
gas
properties in the inner disk remains essentially unknown. Using STIS
on
HST, we propose to quantify the variability of H2 emission
originating
within the inner holes of transitional disks and explore its
implications
on dust distribution and planet formation.
STIS/CCD
11606
Dynamical
Hypermassive Black Hole Masses
We
will use STIS spectra to derive the masses of 5 hypermassive black
holes
(HMBHs). From the observed scaling relations defined by less
massive
spheroids, these objects are expected to reside at the nuclei of
host
galaxies with stellar velocity dispersions greater than 320 km/s.
These
5 targets have confirmed regular gas distributions on the scales
of
the black hole sphere of influence. It is essential that the sphere
of
influence is resolved for accurate determinations of black hole mass
(0.1").
These scales cannot be effectively observed from the ground.
Only
two HMBHs have had their masses modeled so far; it is impossible to
draw
any general conclusions about the connections between HMBH mass and
their
massive host galaxies. With these 5 targets we will determine
whether
these HMBHs deviate from the scaling relations defined by less
massive
spheroids. A larger sample will allow us to firmly anchor the
high
mass end of the correlation between black hole mass and stellar
velocity
dispersion, and other scaling relations. Therefore we are also
conducting
a SNAPshot program with which we expect to detect a further
24
HMBH candidates for STIS observation in future cycles. At the
completion
of this project we will have populated the high mass end of
the
scaling relations with the sample sizes enjoyed by less massive
spheroids.
STIS/CCD
11844
CCD
Dark Monitor Part 1
The
purpose of this proposal is to monitor the darks for the STIS CCD.
STIS/CCD
11846
CCD
Bias Monitor-Part 1
The
purpose of this proposal is to 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/MA1/MA2
11616
The
Disks, Accretion, and Outflows (DAO) of T Tau Stars
Classical
T Tauri stars undergo magnetospheric accretion, power
outflows,
and possess the physical and chemical conditions in their
disks
to give rise to planet formation. Existing high resolution FUV
spectra
verify that this spectral region offers unique diagnostics of
these
processes, which have the potential to significantly advance our
understanding
of the interaction of a star and its accretion disk. To
date
the limited results are intriguing, with dramatic differences in
kinematic
structure in lines ranging from C IV to H2 among the few stars
that
have been observed. We propose to use HST/COS to survey the disks,
outflows,
and accretion (the DAO) of 26 CTTS and 6 WTTS in the FUV at
high
spectral resolution. A survey of this size is essential to
establish
how properties of accretion shocks, winds and disk irradiation
depend
on disk accretion rate. Specifically, our goals are to (1)
measure
the radiation from and understand the physical properties of the
gas
very near the accretion shock as a function of accretion rate using
emission
line profiles of hot lines (C IV, Si IV, N V, and He II); (2)
measure
the opacity, velocity, and temperature at the base of the
outflow
to constrain outflow models using wind absorption features; and
(3)
characterize the radiation incident on disks and protoplanetary
atmospheres
using H2 line and continuum emission and reconstructed
bright
Ly-alpha line emission.
STIS/CCD/MA2
11568
A
SNAPSHOT Survey of the Local Interstellar Medium: New NUV Observations
of
Stars with Archived FUV Observations
We
propose to obtain high-resolution STIS E230H SNAP observations of
MgII
and FeII interstellar absorption lines toward stars within 100
parsecs
that already have moderate or high-resolution far-UV (FUV),
900-1700
A, observations available in the MAST Archive. Fundamental
properties,
such as temperature, turbulence, ionization, abundances, and
depletions
of gas in the local interstellar medium (LISM) can be
measured
by coupling such observations. Due to the wide spectral range
of
STIS, observations to study nearby stars also contain important data
about
the LISM embedded within their spectra. However, unlocking this
information
from the intrinsically broad and often saturated FUV
absorption
lines of low-mass ions, (DI, CII, NI, OI), requires first
understanding
the kinematic structure of the gas along the line of
sight.
This can be achieved with high resolution spectra of high-mass
ions,
(FeII, MgII), which have narrow absorption lines, and can resolve
each
individual velocity component (interstellar cloud). By obtaining
short
(~10 minute) E230H observations of FeII and MgII, for stars that
already
have moderate or high- resolution FUV spectra, we can increase
the
sample of LISM measurements, and thereby expand our knowledge of the
physical
properties of the gas in our galactic neighborhood. STIS is the
only
instrument capable of obtaining the required high resolution data
now
or in the foreseeable future.
STIS/MA1/MA2
11857
STIS
Cycle 17 MAMA Dark Monitor
This
proposal monitors the behavior of the dark current in each of the
MAMA
detectors.
The
basic monitor takes two 1380s ACCUM darks each week with each
detector.
However, starting Oct 5, pairs are only included for weeks
that
the LRP has external MAMA observations planned. The weekly pairs of
exposures
for each detector are linked so that they are taken at
opposite
ends of the same SAA free interval. This pairing of exposures
will
make it easier to separate long and short term temporal variability
from
temperature dependent changes.
For
both detectors, additional blocks of exposures are taken once every
six
months. These are groups of five 1314s FUV-MAMA Time-Tag darks or
five
3x315s NUV ACCUM darks distributed over a single SAA-free interval.
This
will give more information on the brightness of the FUV MAMA dark
current
as a function of the amount of time that the HV has been on, and
for
the NUV MAMA will give a better measure of the short term
temperature
dependence.
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/UVIS/IR
11909
UVIS
Hot Pixel Anneal
The
on-orbit radiation environment of WFC3 will continually generate new
hot
pixels. This proposal performs the procedure required for repairing
those
hot pixels in the UVIS CCDs. During an anneal, the two-stage
thermo-electric
cooler (TEC) is turned off and the four-stage TEC is
used
as a heater to bring the UVIS CCDs up to ~20 deg. C. As a result of
the
CCD warmup, a majority of the hot pixels will be fixed; previous
instruments
such as WFPC2 and ACS have seen repair rates of about 80%.
Internal
UVIS exposures are taken before and after each anneal, to allow
an
assessment of the procedure's effectiveness in WFC3, provide a check
of
bias, global dark current, and hot pixel levels, as well as support
hysteresis
(bowtie) monitoring and CDBS reference file generation. One
IR
dark is taken after each anneal, to provide a check of the IR
detector.
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 05
05
SIGNIFICANT
EVENTS: (None)