HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORTÂ Â Â # 4556
PERIOD
COVERED: UT February 27, 2008 (DOY 058)
OBSERVATIONS
SCHEDULED
FGS
11298
Calibrating
Cosmological Chronometers: White Dwarf Masses
We
propose to use HST/FGS1R to determine White Dwarf {WD} masses. The
unmatched
resolving power of HST/FGS1R will be utilized to follow up
four
selected WD binary pairs. This high precision obtained with
HST/FGS1R
simply cannot be equaled by any ground based technique. This
proposed
effort complements that done by CoI Nelan in which a sample of
WDs
is being observed with HST/FGS1R. This proposal will dramatically
increase
the number of WDs for which dynamical mass measurements are
possible,
enabling a better calibration of the WD mass-radius relation,
cooling
curves, initial to final mass relations, and ultimately giving
important
clues to the star formation history of our Galaxy and the age
of
its disk as well as in other galaxies. {This project is part of
Subasavage's
PhD thesis work at Georgia
State University.}
NIC1/NIC2/NIC3
8795
NICMOS
Post-SAA calibration - CR Persistence Part 6
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 i
mages.
Each observation will need its own CRMAP, as different SAA
passages
leave different imprints on the NICMOS detectors.
NIC2
11135
Extreme
makeovers: Tracing the transformation of massive galaxies at
z~2.5
To
obtain a full spectroscopic census of the universe at z~2.5 we have
conducted
a near-infrared spectroscopic survey for K-selected galaxies.
We
found that, in contrast to the local universe, massive high-redshift
galaxies
span a wide range of properties, varying from (dusty) star
burst
to "red and dead" galaxies. This may imply that massive galaxies
transform
from star-forming to quiescent galaxies in the targeted
redshift
range. To understand whether the 9 quiescent galaxies in our
sample
are the progenitors of local elliptical, we are observing them in
the
current cycle with NIC2. For cycle 16 we propose to complete our
sample
of massive z~2.5 galaxies and image the remaining 10 galaxies,
which
all have emission lines. Based on emission-line diagnostics, 6 of
these
galaxies are identified as star-forming objects and 4 harbor an
active
galactic nucleus. The goals are to 1) determine whether star
formation
in massive z~2.5 galaxies takes place in disks or is triggered
by
merger activity, 2) derive the contribution of AGNs to the rest-frame
optical
emission, and 3) test whether the morphologies are consistent
with
the idea that the star-forming galaxies, AGNs, and quiescent
galaxies
represent subsequent phases of an evolutionary sequence. The
combination
of both programs will provide the first morphological study
of
a spectroscopically confirmed massive galaxy sample at z~2.5.
NIC2
11143
NICMOS
imaging of submillimeter galaxies with CO and PAH redshifts
We
propose to obtain F110W and F160W imaging of 10 z~2.4 submillimeter
galaxies
{SMGs} whose optical redshifts have been confirmed by the
detection
of millimeter CO and/or mid- infrared PAH emission. With the
4000A
break falling within/between the two imaging filters, we will be
able
to study these sources' spatially resolved stellar populations
{modulo
extinction} in the rest-frame optical. SMGs' large luminosities
appear
to be due largely to merger-triggered starbursts; high-resolution
NICMOS
imaging will help us understand the stellar masses, mass ratios,
and
other properties of the merger progenitors, valuable information in
the
effort to model the mass assembly history of the universe.
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.
NIC3
11120
A
Paschen-Alpha Study of Massive Stars and the ISM in the Galactic
Center
The
Galactic center (GC) is a unique site for a detailed study of a
multitude
of complex astrophysical phenomena, which may be common to
nuclear
regions of many galaxies. Observable at resolutions
unapproachable
in other galaxies, the GC provides an unparalleled
opportunity
to improve our understanding of the interrelationships of
massive
stars, young stellar clusters, warm and hot ionized gases,
molecular
clouds, large scale magnetic fields, and black holes. We
propose
the first large-scale hydrogen Paschen alpha line survey of the
GC
using NICMOS on the Hubble Space Telescope. This survey will lead to
a
high resolution and high sensitivity map of the Paschen alpha line
emission
in addition to a map of foreground extinction, made by
comparing
Paschen alpha to radio emission. This survey of the inner 75
pc
of the Galaxy will provide an unprecedented and complete search for
sites
of massive star formation. In particular, we will be able to (1)
uncover
the distribution of young massive stars in this region, (2)
locate
the surfaces of adjacent molecular clouds, (3) determine
important
physical parameters of the ionized gas, (4) identify compact
and
ultra-compact HII regions throughout the GC. When combined with
existing
Chandra and Spitzer surveys as well as a wealth of other
multi-wavelength
observations, the results will allow us to address such
questions
as where and how massive stars form, how stellar clusters are
disrupted,
how massive stars shape and heat the surrounding medium, and
how
various phases of this medium are interspersed.
WFPC2
11030
WFPC2
WF4 Temperature Reduction #3
In
the fall of 2005, a serious anomaly was found in images from the WF4
CCD
in WFPC2. The WF4 CCD bias level appeared to have become unstable,
resulting
in sporadic images with either low or zero bias level. The
severity
and frequency of the problem was rapidly increasing, making it
possible
that WF4 would soon become unusable if no work-around were
found.
Examination of bias levels during periods with frequent WFPC2
images
showed low and zero bias episodes every 4 to 6 hours. This
periodicity
is driven by cycling of the WFPC2 Replacement Heater, with
the
bias anomalies occurring at the temperature peaks. The other three
CCDs
{PC1, WF2, and WF3} appear to be unaffected and continue to operate
properly.
Lowering the Replacement Heater temperature set points by a
few
degrees C effectively eliminates the WF4 anomaly. On 9 January 2006,
the
upper set point of the WFPC2 Replacement Heater was reduced from
14.9C
to 12.2C. On 20 February 2006, the upper set point was reduced
from
12.2C to 11.3C, and the lower set point was reduced from 10.9C to
10.0C.
These changes restored the WF4 CCD bias level; however, the bias
level
has begun to trend downwards again, mimicking its behavior in late
2004
and early 2005. A third temperature reduction is planned for March
2007.
We will reduce the upper set point of the heater from 11.3C to
10.4C
and the lower set point from 10.0C to 9.1C. The observations
described
in this proposal will test the performance of WFPC2 before and
after
this temperature reduction. Additional temperature reductions may
be
needed in the future, depending on the performance of WF4. Orbits:
internal
26, external 1
WFPC2
11222
Direct
Detection and Mapping of Star Forming Regions in Nearby, Luminous
Quasars
We
propose to carry out narrow-band emission line imaging observations
of
8 quasars at z=0.05-0.15 with the WFPC2 ramp filters and with the
NICMOS
narrow-band filters. We will obtain images in the [O II], [O
III],
H-beta, and Pa-alpha emission line bands to carry out a series of
diagnostic
tests aimed at detecting and mapping out star-forming regions
in
the quasar host galaxies. This direct detection of star-forming
regions
will confirm indirect indications for star formation in quasar
host
galaxies. It will provide a crucial test for models of quasar and
galaxy
evolution, that predict the co-existence of starbursts and
"monsters"
and will solve the puzzle of why different indicators of star
formation
give contradictory results. A secondary science goal is to
assess
suggested correlations between quasar luminosity and the size of
the
narrow-line region.
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)
                             Â
SCHEDULEDÂ Â Â Â Â SUCCESSFUL
FGS
GSacq                     08                08                 Â
FGS
REacq                     06                 06                Â
OBAD
with Maneuver      28                 28              Â
SIGNIFICANT
EVENTS:
FLASH
REPORT:
WFPC2
CCD4 replacement heater in-flight temperature adjustment
#5
functionally verified At 058/18:40z, the replacement heaters
were
observed turning on when Bay1 fell to 7.22 °C. About 7
minutes
later they were disabled when Bay1 reached 8.44 °C as
expected,
functionally verifying the patches.