NASA Hubble Space Telescope Daily Report: # 4490
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 DAILY REPORT # 4490
– Continuing to collect World Class Science
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 uniq ue 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)
