NASA Hubble Space Telescope Daily Report # 3451 (part 2)
NIC2 9834
Finding Planets in the Stellar Graveyard: A Faint Companion Search of
White Dwarfs with NICMOS
We propose to do a deep search for substellar objects in orbit around
white dwarfs with the newly refurbished NICMOS camera as part of the
PI’s doctoral thesis work. Direct imaging of planets around main
sequence stars is difficult due to the large contrast ratio, a problem
which is much less severe for companions to white dwarfs. White dwarfs
are not usually considered in planet searches but recent theoretical
work and observations are motivating new searches for planetary
systems and dust disks around DAZ white dwarfs. We propose to conduct
the search with the NIC2 coronagraph to find resolved companions and
do photometry to search for unresolved companions through Near-IR
excesses. We estimate that the survey will be sensitive to brown
dwarfs, high mass jovian planets, and dust disks. By probing a wide
range of orbital separations and companion masses, this survey will
help to answer questions about the brown dwarf desert, common envelope
evolution, and planet formation. HST and NICMOS provide a unique
capability to do this search, as no ground based observatory with AO
can adequately search for faint companions as close and with such high
contrast.
NIC2 9801
Are OH/IR Stars the Youngest post-AGB stars? A NICMOS Imaging Survey
Essentially all well-characterized preplanetary nebulae {PPNe}–
objects in transition between the AGB and planetary nebula
evolutionary phases – are bipolar, whereas the mass-loss envelopes of
AGB stars are strikingly spherical. In order to understand the
processes leading to bipolar mass-ejection, we need to know at what
stage of stellar evolution does bipolarity in the mass-loss first
manifest itself. We have recently hypothesized that most OH/IR stars
{evolved mass- losing stars with OH maser emission} are very young
PPNe. We are conducting a multiwavelength survey program of imaging
and spectroscopic observations of such objects, using a large,
morphologically unbiased sample selected using IRAS 12-to-25 micron
colors. Our ongoing HST/SNAP imaging survey of the optically bright
half of this sample with WFPC2 and ACS is highly successful: 19/32
objects observed are extended with bipolar/multipolar shapes
{remaining objects are unresolved}. Slightly more than 50% of our
sample are optically too faint or undetected but have strong near-IR
counterparts — we therefore propose a NICMOS SNAPshot imaging survey
of these optically-faint OH/IR stars. These observations are crucial
for determining how and when the bipolar geometry asserts itself. The
results from our NICMOS survey {together with the WFPC2/ACS survey}
will allow us to draw general conclusions about the onset of bipolar
mass-ejection during late stellar evolution. Our complementary program
of interferometric mapping of the OH maser emission in our sources is
yielding kinematic information with spatial resolution comparable to
that in the HST images. The HST/radio data will provide crucial input
for theories of post-AGB stellar evolution. In addition, these data
will also indicate whether the multiple concentric rings, “searchlight
beams”, and truncated equatorial disks recently discovered with HST
in a few PPNe, are common or rare phenomena.
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.
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.
STIS 9786
The Next Generation Spectral Library
We propose to continue the Cycle 10 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] lt
-1.5}, low {[Fe/H] -1.5 to -0.5}, near-solar {[Fe/H] -0.3 to 0.1}, and
super-solar {[Fe/H] gt 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/HRC 9782
Measuring Black Hole Masses in Double Peaked Broad Lined AGNs
To date there have been few black hole {BH} mass estimates for
luminous broad line AGN, including those derived from reverberation
mapping. In this context, objects with “double-peaked” broad lines are
particularly important because the line emission is believed to arise
in a relativistically rotating accretion disk. If this model is
correct, then the BH mass can be determined directly from periodic
variations in the line-profile shape. In two cases {Arp 102B and NGC
1097} such variations have been claimed. The goal of this proposal is
to confront the relativistic disk model for the double-peaked Balmer
lines with independent limits on the central masses for 5 of the
nearest and brightest “double-peaked emitters” {NGC 1097, Arp 102B,
Pictor A, 3C390.3, 3C332}, determined by using STIS long-slit
spectroscopy to map the velocity field of circum-nuclear ionized gas.
These observations will critically test the idea that the line
emission in these objects comes from an accretion disk and thus
provide unique insights into the physical processes operating in both
the BLR and the “central engine”.
WFPC2 9709
POMS Test Proposal: 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.
ACS 9675
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.
STIS/CAL 9628
MAMA Sensitivity and Focus Monitor Cycle 11
Monitor sensitivity of each MAMA grating mode to detect any change due
to contamination or other causes. Also monitor the STIS focus in a
spectroscopic and imaging mode.
STIS 9608
CCD Bias Monitor – Part 2
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 9606
CCD Dark Monitor-Part 2
Monitor the darks for the STIS CCD.
WFPC2 9595
WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt3/3
This dark calibration program obtains 3 dark frames every day to
provide data for monitoring and characterizing the evolution of hot
pixels.
STIS 9455
Mid-Ultraviolet Spectral Templates for Old Stellar Systems
We propose a three-year program to provide both observational and
theoretical mid-ultraviolet {2300A — 3100A} spectral templates for
interpreting the age and metallicity of globular clusters and
elliptical galaxies from spectra of their integrated light. The mid-UV
is the region most directly influenced by stellar age, and is observed
directly in optical and infrared studies of high-redshift quiescent
systems. The reliability of age and metallicity determinations remains
questionable until non-solar metallicities and abundance ratios are
considered, and stars spanning the color-magnitude diagram are
included, as we propose here. With archival HST STIS spectra we have
improved the list of mid-UV atomic line parameters, then calculated
spectra from first principles which match observed spectra of standard
stars up to one- fourth solar metallicity. We will extend both
observations and calculations to stars of solar metallicity and
beyond, and to those in short-lived stages hotter than the
main-sequence turnoff, stars not currently well-represented in
empirical libraries. The necessary line-list improvements will come
from new high-resolution mid-UV spectra of nine field stars. A key
application of the results of this program will be to the old systems
now being discovered as `Extremely Red Objects’ at high redshifts.
Reliable age-dating of these places constraints on the epoch when
large structures first formed in the universe.
FGS 9335
Masses of Pre-Main Sequence Binaries
We propose to continue to map the orbits of young star binaries in the
Taurus and Ophiuchus star forming regions. Our goal is to measure
their masses dynamically. This is important because there are still no
low mass young stars with reliably known masses so calculations of
their evolution to the main sequence are uncalibrated.
NIC1/NIC2/NIC3 8792
NICMOS Post-SAA calibration – CR Persistence Part 3
A new proceedure proposed to alleviate the CR-persistence problem of
NICMOS. Dark frames will be obtained immediately upon exiting the SAA
contour 23, and everytime 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 i mages. Each observation will need its
own CRMAP, as different SAA passages leave different imprints on the
NICMOS detectors.
WFPC2 10082
POMS Test Proposal: WFII backup parallel archive proposal
This is a POMS test proposal designed to simulate scientific plans
ACS/WFC 10056
Extreme Red Stars
ACS provides unprecedented sensitivity in the far red, this coupled
with recent astronomical pushes to ever cooler objects {e.g. new
classifications for L and T stellar dwarfs, and extremely high
redshift galaxies} increases the need for extending the photometric
calibration to include such objects. We propose observations of 2
stellar objects for which STIS spectra will exist, as well as NICMOS
grism. The two targets include a late M dwarf and a T dwarf. The M
dwarf provides a temporal check with WFC and new constraint for the
HRC. The T dwarf provides new results for the WFC.
STIS/CCD 10000
STIS Pure Parallel Imaging Program: Cycle 12
This is the default archival pure parallel program for STIS during
cycle 12.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)
HSTAR 9155: GS Acquisition (3,1,1) @ 263/14:54:15Z failed to Gyro
hold due to SRLE on FGS 1. Under investigation.
COMPLETED OPS REQs: None
OPS NOTES EXECUTED:
1158-2 Adjust NICMOS Error Count Limit @ 263/15:30z
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 60 58 (see HSTAR
9155)
FGS REacq 60 60
FHST Update 114 114
LOSS of LOCK
SIGNIFICANT EVENTS:
Aft Flight Deck Telemetry testing scheduled 265/11:00Z – 20:00Z with
GDOC, SOC, HITT, and CCS using CCS “B” String with CCS Release 4.0.3
and PRD S07200. The purpose of this testing is to verify SM-4
telemetry applicable to Aft Flight Deck, HITT, and SOC procedures and
scenario files.
Battery Capacity Test: Battery 1 returned to FSW 6-Battery system @
261/10:10Z (OR 17035-1). Additionally, the +D SPA was unmasked in FSW
and the Benchmark SOC and SOC 1 safing limits were reset to their
6-battery operational values of 330 A-h and 235 A-h, respectively.
During the following 2 orbits, EPS SE confirmed the system was
operating nominally in SWCC with the OCA enabled. Trickle charge was
entered ~ 37 minutes into orbit day at the 330 A-h Benchmark and the
+D SPA opened as expected. Capacity values will be updated when the
merged data becomes available.
Completed CCS Release 5.0.3 Event Analyzer Monitor and Compare testing
259/260/11:00Z – 17:00Z using CCS D, F, and C strings on Day 259 and
CCS D and C strings on Day 261. CCS Release 5.0.3 events compared
nominally against CCS Release 4.0.3 events. The test was configured
with both real-time and simulated data and submitted to several HST
telemetry scenarios. A few Event Analyzer Tool functions were
exercised.
