Daily Report #4772

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT***** #4772

PERIOD COVERED: 5am January 14 - 5am January 15, 2009 (DOY
************************** 014/1000z-015/1000z)

OBSERVATIONS SCHEDULED

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-lumnious 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 targetting 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 radtion 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.

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.

WFPC2 11956

Hubble Heritage: Side B

We propose a program of 39 orbits to observe 6 targets with WFPC2
following a successful return to science using side B electronics.
These observations will be used for Hubble Heritage releases in the
months leading up to servicing mission 4. Because of launch delays,
our reserve of releasable images is growing dangerously slim. We are
proposing here to replenish one of our important lines of
communication with the public.

We have carefully chosen targets that can efficiently use single
pointings of WFPC2 to obtain images of visually striking and
astrophysically interesting targets. Observations will reach high S/N
and will be dithered and subsampled to improve the resolution and
pixel scale to near ACS/WFC3 quality at a modest cost in exposure
time. Most of the observations will schedule in the interim between a
return to science and the availability of new science proposals that
may be selected in response to an interim call for proposals.

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.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11640 - REACQ(1,2,2) at 015/04:54:56 failed to RGA control at 04:59:56
with QF1STOPF and QSTOP flags set.

Observations affected: ACS 6 and 7, proposal #11236.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

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

FGS GSacq*************** 06***************** 06
FGS REacq*************** 10***************** 09
OBAD with Maneuver* **** 30***************** 30

SIGNIFICANT EVENTS: (None)