Daily # 4300

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4300

PERIOD COVERED: UT February 14, 2007 (DOY 045)

OBSERVATIONS SCHEDULED


WFPC2 10910

HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet

As the nearest galaxy with an optical jet, M87 affords an unparalleled
opportunity to study extragalactic jet phenomena at the highest
resolution. During 2002, HST and Chandra monitoring of the M87 jet
detected a dramatic flare in knot HST-1 located ~1" from the nucleus.
Its optical brightness eventually increased seventy-fold and peaked in
2005; the X- rays show a similarly dramatic outburst. In both bands
HST-1 is still extremely bright and greatly outshines the galaxy
nucleus. To our knowledge this is the first incidence of an optical or
X-ray outburst from a jet region which is spatially distinct from the
core source -- this presents an unprecedented opportunity to study the
processes responsible for non- thermal variability and the X-ray
emission. We propose five epochs of HST/ACS flux monitoring during
Cycle 15, as well as seven epochs of Chandra/ACIS observation {5ksec
each, five Chandra epochs contemporary with HST}. At two of the
HST/ACS epochs we also gather spectral information and map the
magnetic field structure. The results of this investigation are of key
importance not only for understanding the nature of the X-ray emission
of the M87 jet, but also for understanding flares in blazar jets,
which are highly variable, but where we have never before been able to
resolve the flaring region in the optical or X-rays. These
observations will allow us to test synchrotron emission models for the
X- ray outburst, constrain particle acceleration and loss timescales,
and study the jet dynamics associated with this flaring component.

NIC2 10798

Dark Halos and Substructure from Arcs & Einstein Rings

The surface brightness distribution of extended gravitationally lensed
arcs and Einstein rings contains super-resolved information about the
lensed object, and, more excitingly, about the smooth and clumpy mass
distribution of the lens galaxies. The source and lens information can
non-parametrically be separated, resulting in a direct "gravitational
image" of the inner mass-distribution of cosmologically-distant
galaxies {Koopmans 2005; Koopmans et al. 2006 [astro-ph/0601628]}.
With this goal in mind, we propose deep HST ACS-F555W/F814W and
NICMOS-F160W WFC imaging of 20 new gravitational-lens systems with
spatially resolved lensed sources, of the 35 new lens systems
discovered by the Sloan Lens ACS Survey {Bolton et al. 2005} so far,
15 of which are being imaged in Cycle-14. Each system has been
selected from the SDSS and confirmed in two time- efficient HST-ACS
snapshot programs {cycle 13&14}. High-fidelity multi-color HST images
are required {not delivered by the 420s snapshots} to isolate these
lensed images {properly cleaned, dithered and extinction-corrected}
from the lens galaxy surface brightness distribution, and apply our
"gravitational maging" technique. Our sample of 35 early-type lens
galaxies to date is by far the largest, still growing, and most
uniformly selected. This minimizes selection biases and small-number
statistics, compared to smaller, often serendipitously discovered,
samples. Moreover, using the WFC provides information on the field
around the lens, higher S/N and a better understood PSF, compared with
the HRC, and one retains high spatial resolution through drizzling.
The sample of galaxy mass distributions - determined through this
method from the arcs and Einstein ring HST images - will be studied
to: {i} measure the smooth mass distribution of the lens galaxies
{dark and luminous mass are separated using the HST images and the
stellar M/L values derived from a joint stellar-dynamical analysis of
each system}; {ii} quantify statistically and individually the
incidence of mass-substructure {with or without obvious luminous
counter- parts such as dwarf galaxies}. Since dark-matter substructure
could be more prevalent at higher redshift, both results provide a
direct test of this prediction of the CDM hierarchical
structure-formation model.

WFPC2 10918

Reducing Systematic Errors on the Hubble Constant: Metallicity
Calibration of the Cepheid PL Relation

Reducing the systematic errors on the Hubble constant is still of
significance and of immediate importance to modern cosmology. One of
the largest remaining uncertainties in the Cepheid-based distance
scale {which itself is at the foundation of the HST Key Project
determination of H_o} which can now be addressed directly by HST, is
the effect of metallicity on the Cepheid Period-Luminosity relation.
Three chemically distinct regions in M101 will be used to directly
measure and thereby calibrate the change in zero point of the Cepheid
PL relation over a range of metallicities that run from SMC-like,
through Solar, to metallicities as high as the most metal-enriched
galaxies in the pure Hubble flow. ACS for the first time offers the
opportunity to make a precise calibration of this effect which
currently accounts for at least a third of the total systematic
uncertainty on Ho. The calibration will be made in the V and I
bandpasses so as to be immediately and directly applicable to the
entire HST Cepheid-based distance scale sample, and most especially to
the highest-metallicity galaxies that were hosts to the Type Ia
supernovae, which were then used to extend the the distance scale
calibration out to cosmologically significant distances.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

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.

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 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.

NIC3 11080

Exploring the Scaling Laws of Star Formation

As a variety of surveys of the local and distant Universe are
approaching a full census of galaxy populations, our attention needs
to turn towards understanding and quantifying the physical mechanisms
that trigger and regulate the large-scale star formation rates {SFRs}
in galaxies.

NIC3 11082

NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive
Galaxies, Galaxies Beyond

Deep near-infrared imaging provides the only avenue towards
understanding a host of astrophysical problems, including: finding
galaxies and AGN at z 7, the evolution of the most massive galaxies,
the triggering of star formation in dusty galaxies, and revealing
properties of obscured AGN. As such, we propose to observe 60 selected
areas of the GOODS North and South fields with NICMOS Camera 3 in the
F160W band pointed at known massive M 10^11 M_0 galaxies at z 2
discovered through deep Spitzer imaging. The depth we will reach {26.5
AB at 5 sigma} in H_160 allows us to study the internal properties of
these galaxies, including their sizes and morphologies, and to
understand how scaling relations such as the Kormendy relationship
evolved. Although NIC3 is out of focus and undersampled, it is
currently our best opportunity to study these galaxies, while also
sampling enough area to perform a general NIR survey 1/3 the size of
an ACS GOODS field. These data will be a significant resource,
invaluable for many other science goals, including discovering high
redshift galaxies at z 7, the evolution of galaxies onto the Hubble
sequence, as well as examining obscured AGN and dusty star formation
at z 1.5. The GOODS fields are the natural location for HST to
perform a deep NICMOS imaging program, as extensive data from space
and ground based observatories such as Chandra, GALEX, Spitzer, NOAO,
Keck, Subaru, VLT, JCMT, and the VLA are currently available for these
regions. Deep high-resolution near-infrared observations are the one
missing ingredient to this survey, filling in an important gap to
create the deepest, largest, and most uniform data set for studying
the faint and distant universe. The importance of these images will
increase with time as new facilities come on line, most notably WFC3
and ALMA, and for the planning of future JWST observations.

WFPC2 10871

Observations of the Galilean Satellites in Support of the New Horizons
Flyby

On February 28 2007 the New Horizons {NH} spacecraft will fly by
Jupiter on its way to Pluto, and will conduct an extensive series of
observations of the Jupiter system, including the Galilean satellites.
We propose HST observations to support and complement the New Horizons
observations in four ways: 1} Determine the distribution and
variability of Io's plumes in the two weeks before NH closest
approach, to look for correlations with Io- derived dust streams that
may be detected by New Horizons, to understand the origin of the dust
streams; 2} Imaging of SO2 and S2 gas absorption in Io's plumes in
Jupiter transit, which cannot be done by NH; 3} Color imaging of Io's
surface to determine the effects of the plumes and volcanos seen by
New Horizons on the surface- New Horizons cannot image the sunlit
surface in color due to saturation; 4} Imaging of far-UV auroral
emissions from the atmospheres of Io, Europa, and Ganymede in Jupiter
eclipse, near- simultaneously with disk-integrated NH UV spectra, to
locate the source of the UV emissions seen by NH and use the response
of the satellite atmospheres to the eclipse to constrain production
mechanisms.

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 11025

WFPC2 Cycle 15 CTE Monitor

Monitor CTE changes during Cycle 15. Test for chip-to-chip differences
in CTE.

WFPC2 11095

Hubble Heritage Observations of NGC 6050

The Hubble Heritage team will use a single pointing of WFPC2 to obtain
F450W, F555W, F656N, and F814W images of NGC 6050 as part of a public
release image.


FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10692 - REACQ(1,2,1) failed, Search Radius Limit Exceeded on FGS 1

REACQ(1,2,1) at 10:09:24 also failed with search radius limit exceeded
on FGS 1 and second A05 message.

10693 - REAcq(2,3,3) results in fine lock backup

REAcq(2,3,3) scheduled at 045/23:23:08 - 23:31:13 resulted in fine
lock backup (2,0,2) using FGS2, due to (QF3STOPF) stop flag indication
on the secondary FGS3. Pre-reacquisition OBADs showed (RSS) attitude
correction values of 1040.47 and 3.79 arcseconds. Post-reacquisition
OBAD/MAP showed (RSS) value of 12.36 arcseconds.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 07 07
FGS REacq 07 06
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS: (None)