Daily Report #4769

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT****** #4769

PERIOD COVERED: 5am January 9 - 5am January 12, 2009 (DOY
*************************** 009/1000z-012/1000z)

OBSERVATIONS SCHEDULED

WFPC2 11967

WFPC2 Imaging of the Lockman Hole

In order to understand galaxy evolution and constrain theoretical
models, we require both multiwavelength photometry (to robustly
determine physical parameters such as star formation rates and stellar
masses) and detailed morphological information. Galaxy morphology
encodes crucial information about galaxy formation history and the
physical processes that trigger star formation and AGN activity, and
high-resolution imaging for large samples of galaxies is currently
only obtainable with HST. The Lockman Hole has been the target of
extensive multi-wavelength observations from the X-ray to the radio,
and will be the target of the deepest wide-area blankfield thermal IR
observations with Herschel, but currently lacks comprehensive HST
imaging. We propose to obtain WFPC2 imaging of ~500 arcmin2 of the
central region of the Lockman Hole in F606W and F814W, to a depth of
V606~26.8 and I814~26. This imaging is crucial in order to
characterize the sources detected at other wavelengths.

WFPC2 11966

The Recent Star Formation History of SINGS Galaxies

The Spitzer Legacy project SINGS provided a unique view of the current
state of star formation and dust in a sample of galaxies of all Hubble
types. This multi-wavelength view allowed the team to create current
star formation diagnostics that are independent of the dust content
and increased our understanding of the dust in galaxies. Even so,
using the SINGS data alone we can only make rough estimates of the
recent star formation history of these galaxies. The lack of high
resolution observations (especially U-band and H-alpha) means that it
is impossible to estimate the ages of young clusters. In addition, the
low resolution of the Spitzer and ground-based observations means that
what appear to be individual Spitzer sources can actually be composed
of many individual clusters with varying ages. We need to know the
ages, star formation histories, and extinction of these individual
clusters to understand how these clusters form and age and thus
influence the evolution of the galaxy. In this proposal we address
this missing area of SINGS by obtaining high-resolution WFPC2 UBVI &
H-alpha observations to not only accurately locate and determine the
ages of the young stellar clusters in the actively star forming SINGS
galaxies but to also address a variety of other scientific issues.
Over 500 HST orbits and 500 hours of Spitzter observing time have been
dedicated to observations of the SINGS sample. But the HST
observations have not been systematic. By adding a relatively small
fraction of this time for these requested observations, we will
greatly enhance the legacy value of the SINGS observations by creating
a uniform high resolution multi-wavelength HST archive that matches
the quality of the lower resolution SINGS archive.

WFPC2 11962

A New Supernova in the Antennae; Narrowing in on the Hubble Constant
and Dark Energy

A measurement of the Hubble constant to a precision of a few percent
would be a powerful aid to the investigation of the nature of dark
energy and a potent "end-to-end" test of the present cosmological
model. In Cycle 15 we constructed a new, streamlined distance ladder
utilizing high-quality type Ia supernova data and observations of
Cepheids with HST in the near-IR to minimize the dominant sources of
systematic uncertainty in past measurements of the Hubble constant and
reduce its total uncertainty to a little under 5%. Here we propose to
exploit this new route with a rare opportunity to begin reducing the
remaining uncertainty. SN 2007sr in the Antennae (NGC 4038/9) is the
rare SN Ia which is suitable for increasing the precision of small
calibration sample of SNe Ia. Even rarer is that it is close enough
that it's Cepheids are within range of observing with WFPC2 (and
NICMOS, should it return to life). But we need to act fast as the
window of long visibility and fixed orient runs from mid-early
December 2008 to early March 2009. We request 34 orbits with WFPC2 to
find the Cepheids in the SN host. We also request 16 orbits to observe
the Cepheids we find with Camera 2, F160W if NICMOS becomes available
by April 2009 . (If NICMOS does not return we would forgo these
observations and ask the TTRB to let us make them with our own WFC3-IR
allocation, though we much prefer the smaller pixel size of NIC2).

WFPC2 11944

Binaries at the Extremes of the H-R Diagram

We propose to use HST/Fine Guidance Sensor 1r to survey for binaries
among some of the most massive, least massive, and oldest stars in our
part of the Galaxy. FGS allows us to spatially resolve binary systems
that are too faint to observe using ground-based, speckle or optical
long baseline interferometry, and too close to resolve with AO. We
propose a SNAP-style program of single orbit FGS TRANS mode
observations of very massive stars in the cluster NGC 3603, luminous
blue variables, nearby low mass main sequence stars, cool subdwarf
stars, and white dwarfs. These observations will help us to (1)
identify systems suitable for follow up studies for mass
determination, (2) study the role of binaries in stellar birth and in
advanced evolutionary states, (3) explore the fundamental properties
of stars near the main sequence-brown dwarf boundary, (4) understand
the role of binaries for X-ray bright systems, (5) find binaries among
ancient and nearby subdwarf stars, and (6) help calibrate the white
dwarf mass - radius relation.

WFPC2 11797

Supplemental WFPC2 CYCLE 16 Intflat Linearity Check and Filter
Rotation Anomaly Monitor

Supplemental observations to 11029, to cover period from Aug 08 to
SM4. Intflat observations will be taken to provide a linearity check:
the linearity test consists of a series of intflats in F555W, in each
gain and each shutter. A combination of intflats, visflats, and
earthflats will be used to check the repeatability of filter wheel
motions. (Intflat sequences tied to decons, visits 1-18 in prop 10363,
have been moved to the cycle 15 decon proposal 11022 for easier
scheduling.)

Note: long-exposure WFPC2 intflats must be scheduled during ACS
anneals to prevent stray light from the WFPC2 lamps from contaminating
long ACS external exposures.

Note: These are supplemental observations to cover June to SM4 (Oct 8
'08) + 6 months.

FGS 11785

Trigonometric Calibration of the Distance Scale for Classical Novae

The distance scale for classical novae is important for understanding
the stellar physics of their thermonuclear runaways, their
contribution to Galactic nucleosynthesis, and their use as
extragalactic standard candles. Although it is known that there is a
relationship between their absolute magnitudes at maximum light and
their subsequent rates of decline--the well-known maximum-magnitude
rate-of-decline (MMRD) relation--it is difficult to set the zero-point
for the MMRD because of the very uncertain distances of Galactic
novae.

We propose to measure precise trigonometric parallaxes for the
quiescent remnants of the four nearest classical novae. We will use
the Fine Guidance Sensors, which are proven to be capable of measuring
parallaxes with errors of ~0.2 mas, well below what is possible from
the ground.

WFPC2 11612

Eta Carinae's Continuing Instability and Recovery - the 2009 Event

Eta Carinae is the only really observable example of structural
recovery from a massive giant eruption, a "supernova imposter' event.
Moreover it is the only well-observed star above 100 Msun, and its
5.5-year-recurrent spectroscopic events provide extraordinary clues to
its surface instability. This truly unique combination of attributes
makes it valuable for understanding the most massive stars. A fresh
development arose a few years ago: The star has brightened much faster
than before, and appears to have entered a rapid stage in its
post-eruption recovery.

A spectroscopic event will occur at 2009.0, soon after the planned HST
servicing mission. Because of the recent secular trend, this event is
expected to differ from its well-observed 2003.5 predecessor. The
differences will be very important, because they offer clues to
very-massive-star structural instabilities that can't be observed in
any other known way.

Some of the needed observations require HST's high spatial resolution
and UV coverage. We propose an efficient, well-chosen set of STIS and
ACS observations around the critical time. If the servicing mission is
too late for the event, then a subset of the observations will still
be merited.

ACS/SBC 11236

Did Rare, Large Escape-Fraction Galaxies Reionize the Universe?

Lyman continuum photons produced in massive starbursts may have played
a dominant role in the reionization of the Universe. Starbursts are
important contributors to the ionizing metagalactic background at
lower redshifts as well. However, their contribution to the background
depends upon the fraction of ionizing radiation that escapes from the
intrinsic opacity of galaxies below the Lyman limit. Current surveys
suggest that the escape fraction is close to zero in most galaxies,
even among young starbursts, but is large in 15-25% of them.
Non-uniform escape fractions are expected as a result of violent
events creating clear paths in small parts of galaxies. The number of
galaxies observed with high escape fraction will result from the
combination of the intrinsic number with clear lines of sight and
their orientation with respect to the observer. We propose to measure
the fraction of escaping Lyman continuum radiation in a large sample
(47) of z~0.7 starbursts in the COSMOS field. These compact
UV-luminous galaxies are good analogs to high redshift LBGs. Using the
SBC/PR130L we can quickly (1-4 orbits) detect relative escape
fractions (f_LC/f_1500) of 25% or more. This will be the first
measurement of the escape fraction in sources between z=1 and the
local universe. We expect ~10 detections. Stacking will set limits of
4% on the relative escape fraction in the rest. We will correlate the
LC detections with the properties of the galaxies. By targeting z~0.7
in COSMOS, we will have tremendous ancillary information on those
sources. A non-detection in all sources would be significant (99%
confidence). This would imply that QSOs provide the overwhelming
majority of ionizing radiation at z1, requiring substantial evolution
in the processes within Lyman break galaxies which allow large escape
fractions at high redshift.

WFPC2 11130

AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge
Paradigm, Part II

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 {10^6 solar masses}, if they exist, may
offer important clues to the nature of the seeds of supermassive black
holes. Using the SDSS, our group has successfully uncovered a new
population of AGNs with intermediate-mass black holes that reside in
low-luminosity galaxies. However, very little is known about the
detailed morphologies or structural parameters of the host galaxies
themselves, including the crucial question of whether they have bulges
or not. Surprisingly, the majority of the targets of our Cycle 14
pilot program have structural properties similar to dwarf elliptical
galaxies. The statistics from this initial study, however, are really
too sparse to reach definitive conclusions on this important new class
of black holes. We wish to extend this study to a larger sample, by
using the Snapshot mode to obtain WFPC2 F814W images from a parent
sample of 175 AGNs with intermediate- mass black holes selected from
our final SDSS search. We are particularly keen to determine whether
the hosts contain bulges, and if so, how the fundamental plane
properties of the host depend on the mass of their central black
holes. We will also investigate the environment of this unique class
of AGNs.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.)

HSTARS:

11635 - GSAcq(1,2,1) @011/3:25z, REAcq(1,2,1) @011/06:40z &
REAcq(1,2,1) @011/08:16z failed to RGA Hold due to receiving QF1STOPF
and QSTOP flags on FGS1.

REAcq(1,2,1) scheduled from 011/05:01:19 - 05:08:38 was successful.

Observations affected: ACS Proposal ID #11236, observation #5 - 6.

COMPLETED OPS REQUEST:

18370-2 - Adjust NCS CPL Setpoint up to 20.0 degC

COMPLETED OPS NOTES: (None)

********************** SCHEDULED***** SUCCESSFUL

FGS GSacq************** 17***************** 16
FGS REacq************** 28***************** 26
OBAD with Maneuver **** 90***************** 90

SIGNIFICANT EVENTS: (None)