Daily #4002

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4002

PERIOD COVERED: UT November 06, 2005 (DOY 340)

OBSERVATIONS SCHEDULED

ACS/HRC 10556

Neutral Gas at Redshift z=0.5

Damped Lyman-alpha systems {DLAs} are used to track the bulk of the
neutral hydrogen gas in the Universe. Prior to HST UV spectroscopy,
they could only be studied from the ground at redshifts z1.65.
However, HST has now permitted us to discover 41 DLAs at z1.65 in our
previous surveys. Followup studies of these systems are providing a
wealth of information about the evolution of the neutral gas phase
component of the Universe. But one problem is that these 41
low-redshift systems are spread over a wide range of redshifts
spanning nearly 70% of the age of the Universe. Consequently, past
surveys for low-redshift DLAs have not been able to offer very good
precision in any small redshift regime. Here we propose an ACS-HRC-
PR200L spectroscopic survey in the redshift interval z=[0.37, 0.7]
which we estimate will permit us to discover another 41 DLAs. This
will not only allow us to double the number of low-redshift DLAs, but
it will also provide a relatively high-precision regime in the
low-redshift Universe that can be used to anchor evolutionary studies.
Fortunately DLAs have high absorption equivalent width, so
ACS-HRC-PR200L has high-enough resoultion to perform this proposed
MgII-selected DLA survey.

ACS/HRC 10609

Sizes, Shapes, and SEDs: Searching for Mass Segregation in the Super
Star Clusters of Nearby Starburst

We propose to investigate mass segregation and star cluster evolution
and dissolution processes in Super Star Cluster {SSC} populations in a
small sample of nearby starburst galaxies. ACS/HRC and NICMOS images
of these nearby {d 10 Mpc} starbursts can reveal evidence for mass
segregation in the form of variations in size, shape, and color of the
SSCs as a function of wavelength. The compactness of the cluster light
profiles, and hence the stellar mass distributions, is a critical
indicator of the likely fate of an SSC: long life and eventual
evolution into a globular-like cluster, or dissolution. These
observations will allow us to generate spectral energy distributions
{SEDs} for a large sample of the SSCs at all ages and extinctions in
each system. We will combine the SEDs with population synthesis models
and existing ground- based spectra and Spitzer images to estimate
ages, reddenings, and masses thus derive a more complete picture of
the star-formation histories of the galaxies. For the brightest and
most likely virialized among the SSCs we will also constrain their
initial mass functions {IMFs} using high- resolution spectroscopy.
Conclusions about IMFs from this technique require detailed
information about the SSC concentration, light profiles, and virial
status, which are only possible via ACS data. The proposed
observations will provide an extensive and comprehensive data set for
a large number of SSCs. By addressing the issues of mass segregation,
evaporation, and destruction of SSC populations, the proposed
observations will provide strong constraints on theories regarding the
processes involved in the formation and evolution of SSCs and globular
clusters. Given the dire predictions for the lifetime of HST, and its
tremendous impact on the study of SSCs, we feel that the proposed
observations not only are necessary and timely {even urgent} but will
also be a fitting { and possibly final} addition to HST's legacy in
the study of starburst SSCs.

ACS/WFC 10491

A Snapshot Survey of the most massive clusters of galaxies

We propose a snapshot survey of a sample of 124 high X-ray luminosity
clusters in the redshift range 0.3-0.7. Similarly luminous clusters at
these redshifts frequently exhibit strong gravitational lensing. The
proposed observations will provide important constraints on the nature
of the cluster mass distributions and a set of optically bright,
lensed galaxies for further 8-10m spectroscopy. We acknowledge the
broad community interest in this sample and waive our data rights for
these observations.

ACS/WFC 10523

The Halo Shape and Metallicity of Massive Spiral Galaxies

We propose to resolve the stellar populations of the halos of seven
nearby, massive disk galaxies using a SNAP survey with WFC/ACS. These
observations will provide star counts and color-magnitude diagrams 2-3
magnitudes below the tip of the Red Giant Branch along the two
principal axes and one intermediate axis of each galaxy. We will
measure the metallicity distribution functions and stellar density
profiles from star counts down to very low average surface
brightnesses, equivalent to ~31 V-mag per square arcsec. This proposal
will create a unique sampling of galaxy halo properties, as our
targets cover a range in galaxy mass, luminosity, inclination, and
morphology. As function of these galaxy properties this survey will
provide:- the first systematic measurement of radial light profiles
and axial ratios of the diffuse stellar halos and outer disks of
spiral galaxies- a comprehensive analysis of halo metallicity
distributions as function of galaxy type and position within the
galaxy- an unprecedented study of the stellar metallicity and age
distribution in the outer disk regions where the disk truncations
occur- the first comparative study of globular clusters and their
field stellar populations We will use these fossil records of the
galaxy assembly process to test halo formation models within the
hierarchical galaxy formation scheme.

ACS/WFC 10596

AGNs with Intermediate-mass Black Holes: A Test of the Black
Hole-Bulge Paradigm

The recent progress in the study of central black holes in galactic
nuclei has led to a general consensus that supermassive {10^6-10^9
solar mass} black holes are closely connected with the formation and
evolutionary history of large galaxies, especially their bulge
component. Two outstanding issues, however, remain unresolved. Can
central black holes form in the absence of a bulge? And does the mass
function of central black holes extend below 10^6 solar masses?
Intermediate-mass black holes {10^4-10^6 solar masses}, if they exist,
may offer important clues to the nature of the seeds of supermassive
black holes. In a first systematic search using the Sloan Digital Sky
Survey, we have recently discovered 19 Type 1 AGNs with candidate
intermediate-mass black holes that reside in low-luminosity,
presumably late-type host galaxies. Follow-up observations with Keck
indicate that these objects obey the low-mass extension of the
well-known correlation between black hole mass and bulge stellar
velocity dispersion. However, very little is known about the host
galaxies themselves, including the crucial question of whether they
have bulges or not. We propose to obtain ACS/WFC images of this unique
sample of AGNs in order to investigate the detailed structural
properties of the host galaxies. We are particularly keen to determine
whether the hosts contain bulges, and if so, where they lie on the
fundamental plane of spheroids compared to the bulges of supermassive
black holes. We will also be able to measure an accurate optical
luminosity for the AGN, which is an essential ingredient to improve
the current mass estimates.

ACS/WFC 10629

Are Field OB Stars Alone?

This SNAP program offers an inexpensive, simple program to search for
low-mass companions of field OB stars. Do field OB stars exist in true
isolation, as suggested by a recent Galactic study, or are they the
tip of the iceberg on a small cluster of low-mass stars as predicted
by the cluster mass function and stellar IMF? Short ACS/WFC V and I
observations proposed here may easily resolve this issue for field OB
stars in the Small Magellanic Cloud. Truly isolated OB stars represent
a theoretical challenge and variation from clusters, in mode of star
formation, and have important consequences for our understanding of
the field stellar population in galaxies. Small clusters around the
field OB stars, on the other hand, may confirm the universality of the
stellar clustering law and IMF.

ACS/WFC/WFPC2 10584

The link between X-ray source and stellar populations in M81

We propose to perform a deep v~26-27.0 HST-ACS survey of the nearby
{3.6 Mpc} spiral galaxy M~81 in order to study the nature of its X-ray
source populations detected with Chandra. For the first time in a
galaxy other than the Milky-Way or the Magelanic Clouds, we will
classify X-ray sources as High-Mass and Low-Mass X-ray binaries
{HMXBs, LMXBs} and investigate how these populations depend on their
galactic environment. The classification will be performed {a} by
finding and classifying unique optical counterparts for the X-ray
sources and {b} studying the stellar populations in their vicinity.
Both tasks require the 0.1'' resolution of HST-ACS which matches well
the positional accuracy of Chandra. Finally we will use these results
together with X-ray binary evolution synthesis models in order to
constrain X-ray binary {XRB} evolution channels. These data will also
be a great resource for studies of the star-formation and star-
cluster populations in one of the prototypical spiral galaxies.

NIC2/ACS/WFC/WFPC2 10532

Kinematics and morphology of the most massive field disk galaxies at
z1

We propose to obtain 1 orbit NIC-2 images of a sample of the 15 most
massive galaxies found at $1 z 1.3$. These were culled from over
20, 000 Keck spectra collected as part of DEEP and are unique among
high redshift massive galaxy samples in being kinematically selected.
We intend to test whether these potentially very young galaxies are
likely precursors to massive local disks, assuming no further merging.
NIC-2 images provide rest-frame optical morphologies that will show
whether they are normal disky systems or instead more disturbed
looking objects with multiple subcomponents, mergers, peculiar
structure, etc. NIC-2 provides near-IR resolutions sufficient to
enable measurements of bulges and disks subcomponents. The near-IR
will fill a critical gap in the broad-band SED photometry of the
galaxy and its subcomponents to estimate mean stellar ages and stellar
masses and to assess whether old stellar bulges and disks are in place
at that time. Finally, this sample will yield the first statistically
significant results on the $z 1$ evolution of the Tully-Fisher
relation for massive galaxies. In addition, we propose parallel
observations with ACS WFC {V and I bands} and WFPC2 {I-band}. These
will target up to 700 galaxies at redshifts 0.7 ... 1.2 for which the
DEEP2 survey has obtained precision redshifts and high-resolution
kinematic data. The added HST morphology and color information will
allow a variety of detailed studies on dynamical, structural, and
photometric evolution of galaxies.

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.

WFPC2 10745

WFPC2 CYCLE 14 INTERNAL MONITOR

This calibration proposal is the Cycle 14 routine internal monitor for
WFPC2, to be run weekly to monitor the health of the cameras. A
variety of internal exposures are obtained in order to provide a
monitor of the integrity of the CCD camera electronics in both bays
{both gain 7 and gain 15 -- to test stability of gains and bias
levels}, a test for quantum efficiency in the CCDs, and a monitor for
possible buildup of contaminants on the CCD windows. These also
provide raw data for generating annual super-bias reference files for
the calibration pipeline.

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:
17605-1 - Off-line +DD,+C,&+B SPA Trim Relays @340/1358z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 11 11
FGS REacq 01 01
OBAD with Maneuver 24 24

SIGNIFICANT EVENTS:
12 Strings Off-Line Flash Report

On DOY 2005/340, Ops Request 17605-1 was successfully executed to
command the -AA and +D SPAs back on-line via IP-099: Procedure to
Modify Commanding of the -AA and +D SPA Trim Relays: Restoration
Procedure. The Ops Request also called upon IP-105: Procedure to
Modify Commanding of the +DD, +C, and +B SPA Trim Relays: Update
Procedure, to command +DD (Batt 1), +C (Batt 2) and +B (Batt 4) SPAs
off-line.

EPS Spacecraft Engineers (SEs) remained on-console for two orbits
following commanding. EPS SEs observed the SPA trim relays opening as
expected.

The Electrical Power Subsystem continues to perform as expected. EPS
SE will closely monitor the battery pressures, battery temperatures,
structure current, and section currents on a daily basis to evaluate
the response to these changes.