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Daily Report #4556

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Old February 28th 08, 05:04 PM posted to sci.astro.hubble
Cooper, Joe
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Posts: 568
Default Daily Report #4556

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science


PERIOD COVERED: UT February 27, 2008 (DOY 058)


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

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 images. 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

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

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

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.


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

HSTARS: (None)




FGS GSacq 08 08
FGS REacq 06 06
OBAD with Maneuver 28 28



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

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