HST Daily Report # 3207 Part 1

HUBBLE SPACE TELESCOPE

DAILY REPORT # 3207

PERIOD COVERED: DOY 267

OBSERVATIONS SCHEDULED (see HSTARS below for possible observation problems)

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 9130

The iron abundance in the Magellanic Clouds and Bridge

The spectra of early-type main-sequence stars provide excellent probes of the
current chemical composition of galaxies. The physics of their atmospheres are
well understood, while their surfaces will normally be unaffected by the
products of interior nuclear reactions. We have previously used optical spectra
of such targets to map the abundances of light metals {such as C, N, O, Mg, Si}
in our Galaxy, in the Magellanic Clouds and in a Bridge of material connecting
the latter. However, we have been unable to obtain iron group abundances
for the
Magellanic System due to the intrinsic weakness of the optical Fe II/III
spectra
and the system’s low metallicity. Here we propose observations of strong Fe III
ultraviolet lines for two Bridge stars, plus an LMC target. These will be
supplemented by AAT and ESO optical spectroscopy plus HST spectra for two
previously observed targets in the middle of the Bridge and in the SMC. Using
non-LTE model atmosphere and careful differential methods, relative abundances
accurate to 0.1 dex should be achievable. These five stars will allow us to
determine key element abundances and ratios {eg. O/Fe} in both Clouds and
across
the Bridge. As well as providing the first detailed comparison of the Bridge’s
metallicity with those of its parent Clouds, it will clarify the evolutionary
history of this system.

Note: Proposal 9130 was possibly compromised because of a STIS problem on
September 24, 2002 05:19

STIS/CCD/MA1 9184

A Survey for Missing Baryons in Highly Ionized Intergalactic Gas at Low
Redshift.

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to observe six
additional low-z QSOs with the STIS FUV E140M echelle mode {7 km s^-1
resolution}. Combined with archival data, this will increase the sample
redshift
path by a factor of ~7 compared to the published data. With the echelle
data, we
will {1} measure the number of O VI absorbers per unit redshift {dN/dz} and
their minimum cosmological mass density with a limiting equivalent width of
W_Lambda ~50 mAngstrom , {2} examine whether the O VI absorption arises in
photoionized, collisionally ionized, or multiphase gas, and {3} study the
dependence of the O VI system properties on environment. In addition to testing
this prediction regarding the location of the missing baryons, the data will
have applications to many other topics such as low-z LyAlpha absorbers and the
physical properties and abundances of gas in the Milky Way halo.

FGS/1 9230

Parallaxes of Magnetic CVs.

Fine Guidance Sensor #1 was used to perform trigonometric parallaxes of
cataclysmic variable {CVs} that are needed to obtain reliable information on
luminosities, accretion rates, and on radii and masses of the stellar
components.

ACS/HRC 9379

Near Ultraviolet Imaging of Seyfert Galaxies: Understanding the Starburst-AGN
Connection

We propose a near-UV snapshot survey of 101 Seyfert galaxies using ACS/HRC and
the filter F330W, a configuration which is optimal to detect faint star forming
regions around their nuclei. These images will complement optical and near-IR
images available in the HST archive, thus providing a panchromatic atlas of the
inner regions of active galaxies, which we will use to study the starburst-AGN
connection. The main goals of this proposal are: {1} Determine the frequency of
circumnuclear starbursts in Seyferts, down to levels which cannot be observed
from the ground; {2} characterize the observational {fluxes, colors, structure,
sizes} and intrinsic {luminosities, masses, ages, global star-formation rate}
properties of these clusters; {3} derive the luminosity functions of young star
clusters around the nucleus of Seyferts and compare these results with those
from normal and starburst galaxies to determine their survival rate close
to the
AGN; {4} address questions about the relation between AGNs and starbursts, like
the possible connection between the masses and luminosities of black holes and
starbursts, and the implications for the evolution of the black holes and their
host galaxy bulges. By adding UV images to the existing optical and near-IR
ones, this project will create an extremely valuable database for astronomers
with a broad range of scientific interests, from the properties of the AGN to
the properties of their host galaxies.

ACS/NICMOS 9404

Spatially Resolved Stellar Populations in Two z~2.5 Gravitational Arcs

We propose to use ACS and NICMOS to observe two gravitationally lensed galaxies
at z~2.5. We will combine these data with existing archival and scheduled GTO
observation to make spatially resolved maps of color, dust, and age for these
objects. We will then use these maps to study the properties of individual
star-forming regions within these galaxies, to search for an underlying old
stellar population between the knots of active star formation, and to test
previous HST and ground-based studies which have hitherto relied on spatially
unresolved colors alone to study stellar population in high redshift
star-forming galaxies. Ours will be the first study of stellar populations of
Lyman Break Galaxies on sub-galactic scales, and will give important new
insights into the way that these high-$z$ galaxies are assembled.

FGS/1 9407

Astrometry of a Star Hosting an Extrasolar Planet: The Mass of Upsilon
Andromedae.

Fine Guidance Sensor #1 was used to determine the astrometric elements
{perturbation orbit semimajor axis and inclination} produced by the outermost
extra-solar planet orbiting the F8V star Upsilon Andromedae. These observations
will permit us to determine the actual mass of the planet by providing the
presently unknown sin i factor intrinsic to the radial velocity method which
discovered this object. An inclination, i = 30degrees, within the range of one
very low precision determination using reanalyzed HIPPARCOS intermediate data
products, would produce the observed radial velocity amplitude, K = 66 ms
with a
companion mass of ~8 M_Jupiter. Such a mass would induce in Upsilon
Andromedae a
perturbation semi-major axis, Alpha = 0arcs0012. The proposed observations will
yield a planetary mass, rather than, as previous investigations have done, only
suggest a planetary mass companion.

ACS/STIS 9451

ACS Imaging and STIS Spectroscopy of Binary Brown Dwarfs

We have compiled a sample of 9 spatially resolved binary brown dwarfs {18
objects}, and now propose ACS imaging and STIS spectroscopic follow-up
observations. While theoretical models on the interplay of chemical and
physical
processes governing brown dwarf atmospheres have reached a high level of
sophistication, interpretation of observational data remains difficult. As
brown
dwarfs never stabilize themselves on the hydrogen main sequence, there is
always
an ambiguity between the temperature or luminosity of any brown dwarf and its
mass or age. The individual components of brown dwarf binaries, however, are
expected to be coeval and have the same underlying chemical composition. This
provides crucial constraints on any model, thus greatly reducing the number of
the free parameters. The aim is to obtain photometric and spectroscopic data to
probe the physical and chemical properties of the brown dwarf atmospheres, as
well as second epoch astrometric data to characterize th e orbital motion. The
study will provide important feedback on theoretical model atmospheres and
evolutionary tracks for brown dwarfs. As such, it will be an important step
towards a better understanding of objects with spectral properties intermediate
between those of giant planets and late-type stars.

ACS 9462

Systemic and Internal Proper Motions of the Magellanic Clouds from Astrometry
with ACS

We request first epoch observations with ACS of Magellanic Cloud fields
centered
on background quasars. Second epoch observations will be requested ~ 5 years
later to allow the measurement of the systemic and internal proper motions of
the Clouds with error <~0.05 mas/year. These motions are of fundamental importance. The systemic motions of the LMC and SMC probe the gravitational potential of the dark halo. The internal proper motion due to rotation can be exploited to yield a rotational parallax distance to the LMC; the first time that this will be done for any galaxy. This is particularly important for the LMC because of its crucial role in the extragalctic distance ladder. Previous measurements of the proper motion of the LMC yield a systemic component ranging from 1.4 mas/year to 3.4 mas/year {differing by several times the quoted errors}, with no useful determination of the internal motions. The main problem with measurements of the proper motion of the LMC has been the lack of a sample of background quasars to use as reference frame. We have recently been able to identify a sample of 54 quasars behind the Magellanic Clouds from their variability characteristics in the MACHO database. With this sample and the advent of ACS an accurate proper motion measurement has become possible for the very first time.

ACS 9468

ACS Grism Parallel Survey of Emission- line Galaxies at Redshift z pl 7

We propose an ACS grism parallel survey to search for emission-line galaxies
toward 50 random lines of sight over the redshift interval 0 < z pl 7. We request ACS parallel observations of duration more than one orbit at high galactic latitude to identify ~ 300 HAlpha emission-line galaxies at 0.2 pl z pl 0.5, ~ 720 O IILambda3727 emission-line galaxies at 0.3 pl z pl 1.68, and pg 1000 Ly-alpha emission-line galaxies at 3 pl z pl 7 with total emission line flux f pg 2* 10^-17 ergs s^-1 cm^-2 over 578 arcmin^2. We will obtain direct images with the F814W and F606W filters and dispersed images with the WFC/G800L grism at each position. The direct images will serve to provide a zeroth order model both for wavelength calibration of the extracted 1D spectra and for determining extraction apertures of the corresponding dispersed images. The primary scientific objectives are as follows: {1} We will establish a uniform sample of HAlpha and O II emission-line galaxies at z<1.7 in order to obtain accurate measurements of co-moving star formation rate density versus redshift over this redshift range. {2} We will study the spatial and statistical distribution of star formation rate intensity in individual galaxies using the spatially resolved emission-line morphology in the grism images. And {3} we will study high-redshift universe using Ly-alpha emitting galaxies identified at z pl 7 in the survey. The data will be available to the community immediately as they are obtained.

ACS 9472

A Snapshot Survey for Gravitational Lenses among z >= 4.0 Quasars

Over the last few years, the Sloan Digital Sky Survey has revolutionized the
study of high-redshift quasars by discovering over 200 objects with redshift
greater than 4.0, more than doubling the number known in this redshift
interval.
The sample includes eight of the ten highest redshift quasars known. We propose
a snapshot imaging survey of a well-defined sample of 250 z > 4.0 quasars in
order to find objects which are gravitationally lensed. Lensing models
including
magnification bias predict that at least 4% of quasars in a flux-limited sample
at z > 4 will be multiply lensed. Therefore this survey should find of order 10
lensed quasars at high redshift; only one gravitationally lensed quasar is
currently known at z > 4. This survey will provide by far the best sample to
date of high-redshift gravitational lenses. The observed fraction of lenses can
put strong constraints on cosmological models, in particular on the
cosmological
constant Lambda. In addition, magnification bias can significantly bias
estimates of the luminosity function of quasars and the evolution thereof; this
work will constrain how important an effect this is, and thereby give us a
better understanding of the evolution of quasars and black holes at early
epochs, as well as constrain models for black hole formation.

ACS 9480

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 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.

NICMOS 9484

The NICMOS Parallel Observing Program

We propose to manage the default set of pure parallels with NICMOS. Our
experience with both our GO NICMOS parallel program and the public parallel
NICMOS programs in cycle 7 prepared us to make optimal use of the parallel
opportunities. The NICMOS G141 grism remains the most powerful survey tool for
HAlpha emission-line galaxies at cosmologically interesting redshifts. It is
particularly well suited to addressing two key uncertainties regarding the
global history of star formation: the peak rate of star formation in the
relatively unexplored but critical 1<= z <= 2 epoch, and the amount of star formation missing from UV continuum-based estimates due to high extinction. Our proposed deep G141 exposures will increase the sample of known HAlpha emission- line objects at z ~ 1.3 by roughly an order of magnitude. We will also obtain a mix of F110W and F160W images along random sight-lines to examine the space density and morphologies of the reddest galaxies. The nature of the extremely red galaxies remains unclear and our program of imaging and grism spectroscopy provides unique information

regarding both the incidence of obscured star bursts and the build up of
stellar
mass at intermediate redshifts. In addition to carrying out the parallel
program
we will populate a public database with calibrated spectra and images, and
provide limited ground- based optical and near-IR data for the deepest parallel
fields.

ACS 9494

ACS Observations of the Optical Jet of MH 2136-428

The total number of well-established extragalactic jets is less than
twenty, and
of these only a handful are blazars. We propose here to use ACS {one orbit} to
image in three bands the newly discovered optical jet in the BL Lac object MH
2136-428. This is the first time that an optical jet has been discovered in a
completely featureless blazar, that is in an object whose nucleus is
particularly highly beamed and/or whose accretion disk power is extremely low.
Moreover, our source has a radio flux more than an order of magnitude fainter
than those typical of the other blazars with optical jets, allowing us to study
an intrinsically weaker jet. Our goals include the study of the jet morphology,
its spectral energy distribution, and the relationship between the jet
properties in blazar and non-blazar sources, extremely relevant for unified
schemes. Only HST can provide the resolution required to study such a faint,
narrow feature, close to the bright nucleus. We are also asking for 10ks of
Chandra observing time to further constrain the jet spectral energy
distribution
and its underlying emission processes.

ACS/CAL 9558

ACS weekly Test

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/WFC 9584

ACS Default {Archival} Pure Parallel Program II.

The Advanced Camera for Surveys (WFC) was used to test ACS pure parallels.

WFPC2 9593

WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt1/3

This dark calibration program obtains 3 dark frames every day to provide data
for monitoring and characterizing the evolution of hot pixels.

CAL/WF2 9597

Intflat Sweep, Visflat Sweep, and Filter Anomaly Check

No abstract available.

STIS 9605

CCD Dark Monitor-Part 1

Monitor the darks for the STIS CCD

STIS 9607

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 9631