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       # 4490

PERIOD COVERED: UT November 15, 2007 (DOY 319)

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 11191

NICMOS Imaging of a z>4 High-Redshift Ultraluminous Submillimeter Source

We propose 16 orbits of deep NICMOS 1.6 um imaging of GOODS850-5, a

unique z>4 candidate SCUBA source that is bright in the submillimeter

{submm} but extremely faint at all other wavelengths. GOODS850-5 is a 11

mJy 850 um source discovered in our GOODS- N SCUBA survey. It does not

have a radio counterpart and its accurate location was recently

determined with the SMA interferometer. It is not detected by the

GOODS-N HST ACS imaging and is just above the detection limit of the

ultradeep Spitzer imaging at 3.6-24 um. Its faint radio flux and its

Spitzer color suggest a redshift of z>4, and potentially even z>6. It

has an incredible star formation rate of ~1000 solar mass per year, and

it can quickly grow into a >10^11 solar mass massive galaxy. Radio faint

submm sources like GOODS850-5 may be a new population of high-redshift

massive galaxies that are not picked up by any of the previous optical,

near-IR, and radio surveys, and therefore it is crucial to obtain the

redshift of GOODS850-5. However, because of its extreme optical

faintness, the only way to constrain its redshift is photometric

redshift with the existing Spitzer photometry and the proposed NICMOS

1.6 um photometry. NICMOS is the only instrument that can provide

information about its redshift and morphology among all space- based and

ground-based instruments at all wavelengths. The proposed observation

will provide unique insight on galaxy evolution and mass assembly at

high redshift.

WFPC2 11093

Hubble Heritage Observations of PNe with WFPC2

This is a proposal for observation of a set of PNe using a common WFPC2

observation sequence.

WFPC2 11134

WFPC2 Tidal Tail Survey: Probing Star Cluster Formation on the Edge

The spectacular HST images of the interiors of merging galaxies such as

the Antennae and NGC 7252 have revealed rich and diverse populations of

star clusters created over the course of the interaction. Intriguingly,

our WFPC2 study of tidal tails in these and other interacting pairs has

shown that star cluster birth in the tails does not follow a similarly

straightforward evolution. In fact, cluster formation in these

relatively sparse environments is not guaranteed -- only one of six

tails in our initial study showed evidence for a significant population

of young star clusters. The tail environment thus offers the opportunity

to probe star cluster formation on the edge of the physical parameter

space {e.g., of stellar and gas mass, density, and pressure} that

permits it to occur. We propose to significantly extend our pilot sample

of optically bright, gas-rich tidal tails by a factor of 4 in number to

include a more diverse population of tails, encompassing major and minor

mergers, gas-rich and gas-poor tails, as well as early, late, and merged

interaction stages. With 21 orbits of HST WFPC2 imaging in the F606W and

F814W filters, we can identify, roughly age-date, and measure sizes of

star clusters to determine what physical parameters affect star cluster

formation. WFPC2 imaging has been used effectively in our initial study

of four mergers, and it will be possible in this program to reach

similar limits of Mv=-8.5 for each of 16 more tails. With the much

larger sample we expect to isolate which factors, such as merger stage,

HI content, and merger mass ratio, drive the formation of star clusters.

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               04                  04 

FGS REacq               08                  08

OBAD with Maneuver 24                  24  

SIGNIFICANT EVENTS: (None)