NASA Hubble Space Telescope Daily Report #4229

HUBBLE SPACE TELESCOPE DAILY REPORT # 4229

– Continuing to collect World Class Science

PERIOD COVERED: UT October 27,28,29, 2006 (DOY 300.301,302)

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 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.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration – CR Persistence Part 4

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.

ACS/WFC 11015

The Proper Motion of Supernova Remnant E0509-67.5

We propose to measure independently the proper motion expansions of the ejecta and forward shock in E0509-67.5. The metal-enriched reverse-shock-heated ejecta emits only in X-rays, while the forward shock is traced to high precision by H alpha emission. The proposed measurements require the unique high resolution imaging capabilities of Chandra and Hubble. The optical {forward shock} and X-ray {ejecta} results will yield important constraints on the remnant’s evolutionary state; we will search in particular for evidence of cosmic-ray modified dynamics. An important component of this project is an integrated theoretical investigation using realistic models of SN Ia explosions evolved to the remnant stage.

ACS/WFC 10911

Calibration of ACS F814W Surface Brightness Fluctuations

The surface brightness fluctuations {SBF} method has emerged as the primary distance indicator for mapping local large-scale structures {Virgo, Fornax}, as well as the velocity field out to nearly 15,000 km/s {z < 0.05}. This is because other precision distance indicators either lack the requisite depth {Cepheids, TRGB} or are too rare for adequate sampling {supernovae}, while more traditional methods {Tully-Fisher, fundamental plane} lack the necessary precision. The SBF method is now being used with great success in several major ACS Wide Field Camera programs. However, whereas the band of choice for the nearby structure studies has been F850LP, for the distant large-scale flow studies it is F814W because of its much greater throughput. As a result, the current calibration for the more distant studies is inadequate. We propose to establish the first systematic calibration of the SBF method in the important F814W ACS WFC bandpass. We will do this by measuring SBF in an optimized sample of galaxies in the nearby compact Fornax cluster. Given the large amount of effort and HST time being dedicated to F814W SBF measurements, it is imperative that we correct this outstanding calibration problem while time remains. For an extremely modest expenditure of orbits, we will remove a significant systematic error and vastly improve the overall accuracy of the ongoing ACS F814W SBF work. These data will also greatly enhance the legacy value of the HST archive for future SBF studies.

ACS/WFC 10905

The Dynamic State of the Dwarf Galaxy Rich Canes Venatici I Region

With accurate distances, the nearest groups of galaxies can be resolved in 3 dimensions and the radial component of the motions of galaxies due to local density perturbations can be distinguished from cosmological expansion components. Currently, with the ACS, galaxy distances within 8 Mpc can be measured effectively and efficiently by detecting the tip of the red giant branch {TRGB}. Of four principal groups at high galactic latitude in this domain, the Canes Venatici I Group {a} is the least studied, {b} is the most populated, though overwhelmingly by dwarf galaxies, and {c} is likely the least dynamically evolved. It is speculated that galaxies in low mass groups may fail to retain baryons as effectively as those in high mass groups, resulting in significantly higher mass-to-light ratios. The CVn I Group is suspected to lie in the mass regime where the speculated astrophysical processes that affect baryon retention are becoming important.

ACS/HRC/WFC 10896

An Efficient ACS Coronagraphic Survey for Debris Disks around Nearby Stars

We propose to finish our Cycle 11 optical survey for nearby debris disks using the ACS/HRC coronagraph. Out of 43 orbits originally proposed for the survey, 23 orbits were allocated, leading to a survey of 22 stars, from which two new debris disks were imaged for the first time. Our analysis of the initial survey gives an empirical estimate for the detection rate of debris disks relative to heliocentric distance and dust optical depth. Our target list for Cycle 15 is now optimized to yield more frequent disk detections. Likewise our observing strategy is improved to maximize sensitivity per telescope orbit allocated. Therefore we present the most efficient survey possible. The scientific motivation is to obtain scattered light images of previously unresolved debris disks to determine their viewing geometry and physical architecture, both of which may characterize the underlying planetary system. We choose 25 debris disk targets for which we predict a detection rate of 25% ? 5%. Four targets have extrasolar planets from which the viewing geometry revealed by a disk detection will resolve the v sin{i} ambiguity in the planet masses. These targets present the remarkable opportunity of finally seeing a debris disk in system with known planets.

ACS/HRC/WFC 10758

ACS CCDs daily monitor

This program consists of a set of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. The files, biases and dark will be used to create reference files for science calibration. This programme will be for the entire lifetime of ACS. Changes from cycle 13:- The default gain for WFC is 2 e-/DN. As before bias frames will be collected for both gain 1 and gain 2. Dark frames are acquired using the default gain {2}. This program cover the period May, 31 2006- Oct, 1-2006. The first half of the program has a different proposal number: 10729.

ACS/HRC 10738

Earth Flats

Sky flats will be obtained by observing the bright Earth with the HRC and WFC. These observations will be used to verify the accuracy of the flats currently in the pipeline and to monitor any changes. Weekly coronagraphic monitoring is required to assess the changing position of the spots.

ACS/WFC/NIC3 10632

Searching for galaxies at z>6.5 in the Hubble Ultra Deep Field

We propose to obtain deep ACS {F606W, F775W, F850LP} imaging in the area of the original Hubble Ultra Deep Field NICMOS parallel fields and – through simultaneous parallel observations – deep NICMOS {F110W, F160W} imaging of the ACS UDF area. Matching the extreme imaging depth in the optical and near-IR bands will result in seven fields with sufficiently sensitive multiband data to detect the expected typical galaxies at z=7 and 8. Presently no such a field exist. Our combined optical and near-IR ultradeep fields will be in three areas separated by about 20 comoving Mpc at z=7. This will allow us to give a first assessment of the degree of cosmic variance. If reionization is a process extending over a large redshift interval and the luminosity function doesn’t evolve strongly beyond z=6, these data will allow us to identify of the order of a dozen galaxies at 6.5 < z < 8.5 - using the Lyman break technique - and to place a first constrain on the luminosity function at z>6.5. Conversely, finding fewer objects would be an indication that the bulk of reionization is done by galaxies at z=6. By spending 204 orbits of prime HST time we will capitalize on the investment of 544 prime orbits already made on the Hubble Ultra Deep Field {UDF}. We have verified that the program as proposed is scheduable and that it will remain so even if forced to execute in the 2-gyro mode. The data will be non-proprietary and the reduced images will be made public within 2 months from the completion of the observations.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10489 – GSAcq(1,2,1) scheduled at 301/00:46:22 results in finelock backup (1,0,1) using FGS-1 due to a stop flag (QF2STOPF) on FGS-2. Pre-acquisition OBADs had (RSS) attitude error corrections values of 4432.82 and 12.88 arcseconds. Post-acquisition OBAD/MAP had 3-axis (RSS) value of 4.93 arcseonds.

10490 – GSAcq (2,1,2) failed due to search radius limit exceeded on FGS At 303/04:52:46 GSAcq (2,1,2) scheduled for 303/04:49:33-04:57:00 failed to RGA control due to search radius limit exceeded on FGS 1. OBAD #1 RSS = 7082.47 OBAD #2 RSS = 8.71 At 303/06:28:51 REAcq (2,1,2) scheduled for 303/06:25:28-06:32:55 failed to RGA control due to search radius limit exceeded on FGS 1. OBAD #1 RSS= 3289.39 a-s OBAD #2 RSS = 17.54 a-s OBAD MAP RSS = 2585.32 a-s

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                          SCHEDULED      SUCCESSFUL
FGS GSacq               29                     28
FGS REacq               13                     12
OBAD with Maneuver  84                     84

SIGNIFICANT EVENTS: (None)