Notice: Due to the conversion of some ACS WFC or HRC observations into

WFPC2, or NICMOS observations after the loss of ACS CCD science

capability in January, there may be an occasional discrepancy between a

proposal's listed (and correct) instrument usage and the abstract that

follows it.

 

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

 

DAILY REPORT      # 4476

 

PERIOD COVERED: UT October 25, 2007 (DOY 298)

 

OBSERVATIONS SCHEDULED

 

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 DARKs. 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 11068

 

NICMOS A-Star Spectrophotometric Observations

 

Now that the Cohen A-star fluxes have been verified in the IR by the

four cycle 14 NICMOS grism observations from program 10754, verification

of four more of these Cohen SEDs will be done in Cycle 15. All 8 stars

are selected from the Spitzer IRAC photometric calibration target lists,

{Tables 1-2} in Reach et al. 2005, PASP, 117,978; and all 8 A-stars are

near the north ecliptic pole, ie near the JWST continuous viewing zone.

The baseline plan for JWST NIRSpec calibration is to use the Cohen

modeled flux beyond the 2.5micron NICMOS limit. Because of intrinsic

variation within the same spectral type there is some statistical

scatter expected in the precision of the Cohen flux extrapolation that

is based on models. Thus, the ensemble JWST flux calibration based on an

average over 8 stars should be sqrt{8} more accurate than a sensitivity

based on just one A-star. In addition to JWST calibration, this program

supports spectrophotometric cross calibration of HST and Spitzer. The

targets are chosen to be faint enough for unsaturated observations with

JWST NIRSpec, yet still bright enough for high signal to noise in

relatively short observations with HST+NICMOS and with Spitzer+IRAC.

 

NIC3 11082

 

NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive

Galaxies, Galaxies Beyond Reionization, and the High Redshift Obscured

Universe

 

(uses ACS/SBC and WFPC2)

 

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 11022

 

WFPC2 Cycle 15 Decontaminations and Associated Observations

 

This proposal is for the WFPC2 decons. Also included are instrument

monitors tied to decons: photometric stability check, focus monitor,

pre- and post-decon internals {bias, intflats, kspots, & darks}, UV

throughput check, VISFLAT sweep, and internal UV flat check.

 

WFPC2 11178

 

Probing Solar System History with Orbits, Masses, and Colors of

Transneptunian Binaries

 

The recent discovery of numerous transneptunian binaries {TNBs} opens a

window into dynamical conditions in the protoplanetary disk where they

formed as well as the history of subsequent events which sculpted the

outer Solar System and emplaced them onto their present day heliocentric

orbits. To date, at least 47 TNBs have been discovered, but only about a

dozen have had their mutual orbits and separate colors determined,

frustrating their use to investigate numerous important scientific

questions. The current shortage of data especially cripples scientific

investigations requiring statistical comparisons among the ensemble

characteristics. We propose to obtain sufficient astrometry and

photometry of 23 TNBs to compute their mutual orbits and system masses

and to determine separate primary and secondary colors, roughly tripling

the sample for which this information is known, as well as extending it

to include systems of two near-equal size bodies. To make the most

efficient possible use of HST, we will use a Monte Carlo technique to

optimally schedule our observations.

 

WFPC2 11194

 

Beyond the Bullet: Direct Detection of Dark Matter in Merging Galaxy

Clusters

 

Our comparison of the distribution of baryons {stars and gas} and mass

{from weak lensing} in the "Bullet" Cluster has recently yielded

concrete evidence for dark matter independent of basic assumptions

regarding the nature of the gravitational force. The one incomplete

aspect of the argument relates to potential, although highly unlikely,

coincidences {special alignments along the line of sight, and/or

fortuitous canceling in non-standard gravitational models} that can

always be invoked against results derived from the study of one object.

Therefore, we propose to complete this line of investigations by

increasing the size of our sample with observations of an additional

cluster. Here we propose to obtain HST WFPC2 imaging mosaics around the

cores of the cluster to detect at high significance if the weak

gravitational lensing mass peaks are routinely displaced from the X-ray

plasma clouds and aligned with the galaxy concentrations in interacting

clusters. With a relatively modest allocation of time, we seek to

complete a significant step toward the eventual resolution of the dark

matter question.

 

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)

 

                       SCHEDULED      SUCCESSFUL 

FGS GSacq               09                 09                   

FGS REacq               04                 04                      

OBAD with Maneuver 28                28        

 

SIGNIFICANT EVENTS: (None)