Daily Report #4168

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4168

PERIOD COVERED: UT August 1, 2006 (DOY 213)

OBSERVATIONS SCHEDULED


ACS/WFC 10829

Secular Evolution at the End of the Hubble Sequence

The bulgeless disk galaxies at the end of the Hubble Sequence evolve
at a glacial pace relative to their more violent, earlier-type
cousins. The causes of their internal, or secular evolution are
important because secular evolution represents the future fate of all
galaxies in our accelerating Universe and is a key ingredient to
understanding galaxy evolution in lower-density environments at
present. The rate of secular evolution is largely determined by the
stability of the cold ISM against collapse, star formation, and the
buildup of a central bulge. Key diagnostics of the ISM's stability are
the presence of compact molecular clouds and narrow dust lanes.
Surprisingly, edge-on, pure disk galaxies with circular velocities
below 120 km/s do not appear to contain such dust lanes. We propose to
obtain ACS/WFC F606W images of a well-selected sample of extremely
late-type disk galaxies to measure the characteristic scale size of
the cold ISM and determine if they possess the unstable, cold ISM
necessary to drive secular evolution. Our sample has been carefully
constructed to include disk galaxies above and below the critical
circular velocity of 120 km/s where the dust properties of edge-on
disks change so remarkably. We will then use surface brightness
profiles to search for nuclear star clusters and pseudobulges, which
are early indicators that secular evolution is at work, as well as
measure the pitch angle of the dust lanes as a function of radius to
estimate the central mass concentrations.

ACS/WFC/NIC2 10496

Decelerating and Dustfree: Efficient Dark Energy Studies with
Supernovae and Clusters

We propose a novel HST approach to obtain a dramatically more useful
"dust free" Type Ia supernovae {SNe Ia} dataset than available with
the previous GOODS searches. Moreover, this approach provides a
strikingly more efficient search-and-follow-up that is primarily
pre-scheduled. The resulting dark energy measurements do not share the
major systematic uncertainty at these redshifts, that of the
extinction correction with a prior. By targeting massive galaxy
clusters at z 1 we obtain a five-times higher efficiency in
detection of Type Ia supernovae in ellipticals, providing a
well-understood host galaxy environment. These same deep cluster
images then also yield fundamental calibrations required for future
weak lensing and Sunyaev-Zel'dovich measurements of dark energy, as
well as an entire program of cluster studies. The data will make
possible a factor of two improvement on supernova constraints on dark
energy time variation, and much larger improvement in systematic
uncertainty. They will provide both a cluster dataset and a SN Ia
dataset that will be a longstanding scientific resource.

FGS 10103

FGS Astrometry of a Star Hosting an Extrasolar Planet: The Mass of
Upsilon Andromedae d

We propose observations with HST/FGS to determine the astrometric
elements {perturbation orbit semimajor axis and inclination} produced
by the outermost extra-solar planet orbiting the F8V star Upsilon
Andromedae. These observations will permit us to determine the actual
mass of the planet by providing the presently unknown sin i factor
intrinsic to the radial velocity method which discovered this object.
An inclination, i = 30degrees, within the range of one very low
precision determination using reanalyzed HIPPARCOS intermediate data
products, would produce the observed radial velocity amplitude, K = 66
ms with a companion mass of ~8 M_Jupiter. Such a mass would induce in
Upsilon Andromedae a perturbation semi-major axis, Alpha = 0arcs0012,
easily within the reach of HST/FGS fringe tracking astrometry. The
proposed observations will yield a planetary mass, rather than, as
previous investigations have done, only suggest a planetary mass
companion.

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 10538

Near-IR Spectrophotometry of 2MASSWJ 1207334-393254B - An Extra-Solar
Planetary Mass Companion

We propose to obtain "short" wavelength near-IR diagnostic and
characterizing spectra of the very high probability candidate
extra-solar giant planet {EGP} companion to 2MASSWJ 1207334-393254
{2M1207}, a young brown dwarf and TW Hydrae Association member. Recent
NICMOS camera 1 multi-band photometric imaging of the companion
candidate, 0.77" {54 AU projected} from 2M1207 - initially detected at
longer wavelengths with VLT/NACO - implicate an object of several
Jupiter masses based on cooling models of EGPs and the likely age of
2M1207 {~ 8 Myr}. Physical companionship of the EGP candidate with
2M1207 has been established at the 99.1% level of confidence via
second- epoch NICMOS astrometric observations. Diagnostic spectra in
the 0.8 to 1.9 micron region {unobtainable from the ground and
overlapping the NICMOS imaging observations} will {a} critically
inform on the physical nature of the EGP, {b} provide currently
non-existing information to test/constrain theoretical models of EGP
properties and evolution, and {c} unequivocally confirm the imaging of
a bone fide EGP. Background light from 2M1207 would normally swamp the
EGP spectrum with direct spectral imaging. To obviate this, we propose
PSF-subtracted grism spectra of the EGP using 2M1207 as its own
spectral template via two-orientation high-contrast image subtraction.
The temporal stability of the HST+NICMOS PSF enables self-subtractions
of targets at different field orientations resulting in contrast
enhancements of 5 to 6 stellar magnitudes in the circumstellar
background at ~ 0.8" at these wavelengths. With the grism field
oriented to place the EGP "above" and "below" 2M1207 {at two
observational epochs} two independent spectra of the EGP will emerge
from a difference image. This prototypical spectrum will serve to test
and improve upon current models of young EGPs which predict flux
suppression by molecular absorption in their atmospheres.

WFPC2 10745

WFPC2 CYCLE 14 INTERNAL MONITOR

This calibration proposal is the Cycle 14 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.


FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#10388 REacq(2,1,2) results in fine lock backup @ 213/13:37:40z

The REacq(2,1,2) resulted in fine lock backup (2,0,2).OBAD2 showed
errors of V1=7.44, V2=-5.21, V3=-1.76, and RSS=9.25. The Map at
13:41:25 showed errores of V1=-1.15, V2=-4.97, V3=-2.12, and RSS=
5.52. Observations affected: ACS 67 and 68, NIC 5

COMPLETED OPS REQUEST:

#17865-0 Battery 1 Capacity Test Script & 5 Battery Pressure Limit COP
(completed through step = 18)

#17876-0 Continuous Engineering Recording for Battery 1 BCT (ESTR
Power on @ 214/ 0842z)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 10 10
FGS REacq 04 04
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS:

Battery 1 Capacity Test Flash Report:

Commanding for the Battery 1 Capacity Test started as scheduled on DOY
213/1058 GMT (08/01 at 6:58 am) with the setting of the Battery
Pressure Test for a 5-battery system. Battery 1 was taken off-line and
started discharging on the first opportunity at 1214 GMT (08/01 at
8:14 am). The discharge is expected to continue for approximately 50
hours. Following completion of the discharge, which is expected to
occur around 215/1414 GMT (08/03 at 10:14 am), Battery 1 will be
placed back online in hardware during orbit night. Following its
recovery period, Battery 1 will be placed back on-line in FSW on
216/1655 GMT (08/04 at 12:55 pm).

The Battery 1 discharge switched from the High-rate to the Low-rate
resistor at 213/2122 GMT.