Daily Rpt #4430

Notice: Due to the conversion of some ACS WFC or HRC observations into
WFPC2, or NICMOS observations after the loss of ACS CCD science
capability in January, there may be an occasional discrepancy between
a proposal's listed (and correct) instrument usage and the abstract
that follows it.

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT***** # 4430

PERIOD COVERED: UT August 20, 2007 (DOY 232)

OBSERVATIONS SCHEDULED

WFPC2 10787

Modes of Star Formation and Nuclear Activity in an Early Universe
Laboratory

Nearby compact galaxy groups are uniquely suited to exploring the
mechanisms of star formation amid repeated and ongoing gravitational
encounters, conditions similar to those of the high redshift universe.
These dense groups host a variety of modes of star formation, and they
enable fresh insights into the role of gas in galaxy evolution. With
Spitzer mid-IR observations in hand, we have begun to obtain high
quality, multi-wavelength data for a well- defined sample of 12 nearby
{4500km/s} compact groups covering the full range of evolutionary
stages. Here we propose to obtain sensitive BVI images with the
ACS/WFC, deep enough to reach the turnover of the globular cluster
luminosity function, and WFPC2 U-band and ACS H-alpha images of
Spitzer-identified regions hosting the most recent star formation. In
total, we expect to detect over 1000 young star clusters forming
inside and outside galaxies, more than 4000 old globular clusters in
40 giant galaxies {including 16 early-type galaxies}, over 20 tidal
features, approximately 15 AGNs, and intragroup gas in most of the 12
groups. Combining the proposed ACS images with Chandra observations,
UV GALEX observations, ground-based H-alpha imaging, and HI data, we
will conduct a detailed study of stellar nurseries, dust, gas
kinematics, and AGN.

WFPC2 11024

WFPC2 CYCLE 15 INTERNAL MONITOR

This calibration proposal is the Cycle 15 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.

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

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 DARKs. 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.

NIC2 11219

Active Galactic Nuclei in nearby galaxies: a new view of the origin of
the radio-loud radio- quiet dichotomy?

Using archival HST and Chandra observations of 34 nearby early-type
galaxies {drawn from a complete radio selected sample} we have found
evidence that the radio-loud/radio-quiet dichotomy is directly
connected to the structure of the inner regions of their host galaxies
in the following sense: [1] Radio-loud AGN are associated with
galaxies with shallow cores in their light profiles [2] Radio-quiet
AGN are only hosted by galaxies with steep cusps. Since the brightness
profile is determined by the galaxy's evolution, through its merger
history, our results suggest that the same process sets the AGN
flavour. This provides us with a novel tool to explore the
co-evolution of galaxies and supermassive black holes, and it opens a
new path to understand the origin of the radio-loud/radio-quiet AGN
dichotomy. Currently our analysis is statistically incomplete as the
brightness profile is not available for 82 of the 116 targets. Most
galaxies were not observed with HST, while in some cases the study is
obstructed by the presence of dust features. We here propose to
perform an infrared NICMOS snapshot survey of these 82 galaxies. This
will enable us to i} test the reality of the dichotomic behaviour in a
substantially larger sample; ii} extend the comparison between
radio-loud and radio-quiet AGN to a larger range of luminosities.

NIC2 11329

The Final SHOE; Completing a Rich Cepheid Field in NGC 1309

The Cycle 15 SHOES program {GO 10802} is a large HST program allocated
186 orbits to rebuild the distance ladder using NGC 4258 as a new
anchor, a set of 6 recent, ideal type Ia supernovae and Cepheids in
their hosts, and NICMOS as a single, homogeneous photometer of long
period Cepheids. These tools provide the means to achieve a 4%
measurement of the Hubble constant, an invaluable constraint for
cosmic concordance fits to dark energy models. Unfortunately, the
SHOES NICMOS integrations of long period Cepheids in the last and most
recent nearby type Ia supernova host, NGC 1309, are too short because
the preliminary estimate of its distance, 30 Mpc, was too low. Our
refined estimate now based on the full reduction of both our Cycle 14
and 15 ACS data is 36 Mpc, or 0.4 mag farther. Fortunately, Nature was
extremely kind providing a single rich NIC2 field in which we can
fully make up for the shortfall due to its abundance of Cepheids. We
are expensing our final 4 orbits on this field of a dozen P30 day
Cepheids and seek an additional 5 orbits to reach the depth for
measuring the mean F160W magnitudes of the long-period Cepheids with
the necessary signal-to-noise ratios of better than 10.

WFPC2 11023

WFPC2 CYCLE 15 Standard Darks - part 1

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.

WFPC2 11031

CTE Background Dependence Closeout

Measuring the charge transfer efficiency {CTE} of an astronomical CCD
camera is crucial to determining the CCD's photometric fidelity across
the field of view. WFPC2's CTE has degraded steadily over the last 13
years because of continuous exposure to trapped particles in HST's
radiation environment. The fraction of photometric signal lost from
WFPC2's CTI {charge transfer inefficiency} is a function of WFPC2's
time in orbit, the integrated signal in the image, the location of the
image on the CCD, and the background signal. Routine monitoring of
WFPC2's CTE over the last 13 years permits an assessment of all but
the last condition. The dependence of CTE on background signal must be
characterized, however, because a large fraction of WFPC2 images have
been obtained under conditions of significant sky background. This
program aims to assess the end-of-life CTE of WFPC2's CCDs separately
as a function of background signal. Traditional images of an
off-center field in NGC 5139 {Omega Cen} are recorded after
preflashing {or before postflashing} the CCDs with internal lamps to
provide average background signals of 0-160 e-, which span the range
of sky backgrounds observed in ~99% of long-exposure narrow- and
broad-band WFPC2 images.

WFPC2 11234

A Brief Revisit of the Crab

We propose using WFPC2 to obtain continuum-dominated images of the
Crab pulsar and environs closely duplicating archival exposures from
1994 and 1995. By matching the archival data we can realize ~3mas
precision astrometry with a minimum of systematic effects over a
maximum {~13.5y} baseline. This determines the Crab proper motion to
better than 0.3mas/yr {3km/s} accuracy and measures its position angle
to better than 1.5degrees, i.e. reducing the errors of the best
present {HST archive} measurement by a factor of three. Most
importantly, this provide a nearly systematic-free result. This proper
motion measurement would match the precision of the CXO-measured
angular momentum vector. Comparison of these vectors is the foundation
of an effort to understand the physical origin of the large momentum
kick at pulsar birth.

WFPC2 11289

SL2S: The Strong Lensing Legacy Survey

Recent systematic surveys of strong galaxy-galaxy lenses {CLASS,
SLACS, GOODS, etc.} are producing spectacular results for galaxy
masses roughly below a transition mass M~10^13 Mo. The observed lens
properties and their evolution up to z~0.2, consistent with numerical
simulations, can be described by isothermal elliptical potentials. In
contrast, modeling of giant arcs in X-ray luminous clusters {halo
masses M ~10^13 Mo} favors NFW mass profiles, suggesting that dark
matter halos are not significantly affected by baryon cooling. Until
recently, lensing surveys were neither deep nor extended enough to
probe the intermediate mass density regime, which is fundamental for
understanding the assembly of structures. The CFHT Legacy Survey now
covers 125 square degrees, and thus offers a large reservoir of strong
lenses probing a large range of mass densities up to z~1. We have
extracted a list of 150 strong lenses using the most recent CFHTLS
data release via automated procedures. Following our first SNAPSHOT
proposal in cycle 15, we propose to continue the Hubble follow-up
targeting a larger list of 130 lensing candidates. These are
intermediate mass range candidates {between galaxies and clusters}
that are selected in the redshift range of 0.2-1 with no a priori
X-ray selection. The HST resolution is necessary for confirming the
lensing candidates, accurate modeling of the lenses, and probing the
total mass concentration in galaxy groups up to z~1 with the largest
unbiased sample available to date.

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: (None)

COMPLETED OPS NOTES: (None)

********************** SCHEDULED***** SUCCESSFUL
FGS GSacq************** 06**************** 06
FGS REacq************** 08**************** 08
OBAD with Maneuver 28**************** 28

SIGNIFICANT EVENTS: (None)