Date: October 19th 2006

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4221

PERIOD COVERED: UT October 17, 2006 (DOY 290)

OBSERVATIONS SCHEDULED

ACS/WFC 10595

A Reference Database for Accurate Ages and Metallicities of Globular Clusters in the Magellanic Clouds

We propose to finalize the compilation of a comprehensive database of high-quality ages and metallicities of Simple Stellar Populations {SSPs} in the Milky Way and the Magellanic Clouds We will acquire new ACS imagery for 8 young and intermediate-age globular clusters in the Magellanic Clouds to create high-quality color-magnitude diagrams {CMDs} to enable accurate measurements of their ages and metallicities In concert with a similar analysis of CMD data already available in the HST archive for 8 more such GCs, the resulting database will provide a well-sampled coverage of the full range of ages and metallicities known among globular clusters {0 5 <= Age {Gyr} <= 13 5 and -2 3 <= [Fe/H] <= +0 1, respectively} This database will form the crucial basis for our ongoing, comprehensive multi-wavelength program to: {1} establish empirical relations among SSP colors {from the UV [GALEX] through the mid-IR [Spitzer]}, line strengths, ages and metallicities, and {2} provide a stringent test of the systemic accuracy of age and metallicity determinations using state-of-the-art population synthesis models

ACS/WFC 10816

The Formation History of Andromeda's Extended Metal-Poor Halo

We propose deep ACS imaging in the outer spheroid of the Andromeda galaxy, in order to measure the star formation history of its true halo For the past 20 years, nearly all studies of the Andromeda "halo" were focused on the spheroid within 30 kpc of the galaxy's center, a region now known to host significant substructure and populations with high metallicity and intermediate ages However, two groups have recently discovered an extended metal-poor halo beyond 30 kpc; this population is distinct in its surface-brightness profile, abundance distribution, and kinematics In earlier cycles, we obtained deep images of the inner spheroid {11 kpc on the minor axis}, outer disk {25 kpc on the major axis}, and giant tidal stream, yielding the complete star formation history in each field We now propose deep ACS imaging of 4 fields bracketing this 30 kpc transition point in the spheroid, so that the inner spheroid and the extended halo populations can be disentangled, enabling a reconstruction of the star formation history in the halo A wide age distribution in the halo, as found in the inner spheroid, would imply the halo was assembled through ongoing accretion of satellite galaxies, while a uniformly old population would be a strong indication that the halo was formed during the early rapid collapse of the Andromeda proto-galaxy

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

NIC3/ACS/WFC 10921

Tangential Velocities of Objects in the Orion Nebula and Locating the Embedded Outflow Sources

The Orion Nebula is arguably the Rosetta Stone for studying a very young star cluster and how the radiation and outflowing plasma from its stars interact with ambient material It has been the subject of numerous HST imaging studies, which means that there is good opportunity for determining tangential velocities by obtaining second epoch images during Cycle 15, which may be the last cycle for which the WFPC2 is available These velocities in the plane-of-the-sky will allow us to determine the patterns of outflow from micro-jets smaller than the Solar System to jet driven shocks more than a parsec from their sources Combined with radial velocities, we'll obtain spatial velocities, which are critical to determining where the embedded sources are located that produce the numerous HH objects coming from the Orion-S and BN-KL regions We'll also be able to determine the physics that is operating in the LL Ori type of outflows {where a bipolar jet is being distorted by a slow wind coming from the nebula} We will also be able to search for runaway stars caused by the disintegration of young multiple-star systems All of this is possible because the long-time base of the WFPC2 and ACS observations allow a new level of astrometric precision to be obtained and to be done efficiently by making coordinated parallel observations with all images

WFPC2 10744

WFPC2 Cycle 14 Decontaminations and Associated Observations

This proposal is for the WFPC2 decontamination Also included are instrument monitors tied to decontamination: photometric stability check, focus monitor, pre- and post-decontamination internals {bias, intflats, kspots, & darks}, UV throughput check, VISFLAT sweep, and internal UV flat check

FLIGHT OPERATIONS SUMMARY:

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

HSTARS: 10470 - GSacq (2,3,2) failed due to search radius limit exceeded on FGS 3 GSacq (2,3,2) scheduled at 18:47:51 failed 486 ESB a05, Exceeded SRL OBAD 1 RSS = 5641 51 OBAD 2 RSS = 10 63 MAP @ next AOS (19:43:39) RSS = 17 76

REacq scheduled at 20:24:54 failed with the same indications as the GSacq including a 486 STB a05 message Reacq(2,3,2) OBAD 1 RSS 3845 000 OBAD 2 RSS 8 07 MAP RSS 20 35

REacq(2,3,2) scheduled at 22:03:20 also failed with the same mnemonics and 486 ESB message OBAD 1 RSS 2705 13 OBAD 2 RSS 7 81 No MAP scheduled

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                     SCHEDULED      SUCCESSFUL

FGS GSacq 09 08 FGS REacq 05 03 OBAD with Maneuver 28 28

SIGNIFICANT EVENTS: (None)

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