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
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
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)