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STScI Community Service Science ProgramsIntroductionThe HST observing schedule over the last 8 to 12 months has been geared towards a servicing mission in the late 2008, and exhausting, as far as possible, Cycle 15 and 16 programs. By late-September 2008, a total of 660 GO orbits, including 484 NICMOS orbits, and 279 SNAPs remained to be executed. On September 25 2008, the NICMOS Cooling System (NCS) failed; then on September 28 the side-A electronics failed on the Science Instrument Command & Data Handling (SIC&DH) Unit, leading to the postponement of Servicing Mission 4. The SIC&DH unit was switched successfully to side-B on October 25, and a Call for Cycle 16 Supplemental Proposals was issued on November 17 2008. Those proposals were reviewed by members of the astronomical community.Processing, distributing and reviewing HST proposals takes time, and the results from the Supplemental Review could not be made available earlier than January 13 2009. Once a proposal is accepted, the Phase II needs to be developed, submitted and reviewed, and entered into the HST observing. The observing calendars are built on a weekly basis, and each must be completed 10 days before the first observation is executed. Thus, the earliest that we could anticipate executing Cycle 16 Supplementary programs was early February 2009. In the meantime, efforts to restart the NCS had failed to achieve any lasting success, and the pool of available WFPC2, ACS/SBC and FGS observations was diminishing to the point where it would be depleted completely by January 5th. Clearly, it was important to ensure that HST remained scientifically productive throughout January. After consultations with the Cycle 17 TAC chair, Prof. Rob Kennicutt (Cambridge/Arizona), and the STIC chair, Prof. Brad Peterson (Ohio State), the Director tasked the STScI scientific staff with identifying programs that would be of broad community interest and could be executed throughout January 2009. Those programs would be awarded Director’s Discretionary Time, but the data would have no proprietary time and the teams would receive no grant funding. Several proposals were submitted by staff members, and reviewed by an internal committee, chaired by the former STScI Director, Bob Williams. The two proposals listed on this page were selected for execution. Title: The Recent Star Formation History of SINGS Galaxies PI: Michael Regan ID: 11966 Allocation: 86 Orbits AbstractThe Spitzer Legacy project SINGS provided a unique view of the current state of star formation and dust in a sample of galaxies of all Hubble types. This multi-wavelength view allowed the team to create current star formation diagnostics that are independent of the dust content and increased our understanding of the dust in galaxies. Even so, using the SINGS data alone we can only make rough estimates of the recent star formation history of these galaxies. The lack of high resolution observations (especially U-band and H-alpha) means that it is impossible to estimate the ages of young clusters. In addition, the low resolution of the Spitzer and ground-based observations means that what appear to be individual Spitzer sources can actually be composed of many individual clusters with varying ages. We need to know the ages, star formation histories, and extinction of these indivdual clusters to understand how these clusters form and age and thus influence the evolution of the galaxy. In this proposal we address this missing area of SINGS by obtaining high-resolution WFPC2 UBVI & H-alpha observations to not only accurately locate and determine the ages of the young stellar clusters in the actively star forming SINGS galaxies but to also address a variety of other scientific issues. Over 500 HST orbits and 500 hours of Spitzter observing time have been dedicated to observations of the SINGS sample. But the HST observations have not been systematic. By adding a relatively small fraction of this time for these requested obserations, we will greatly enhance the legacy value of the SINGS observations by creating a uniform high resolution multi-wavelength HST archive that matches the quality of the lower resolution SINGS archive.Title: WFPC2 Imaging of the Lockman Hole PI: Rachel Somerville ID: 11967 Allocation: 125 Orbits AbstractIn order to understand galaxy evolution and constrain theoretical models, we require both multiwavelength photometry (to robustly determine physical parameters such as star formation rates and stellar masses) and detailed morphological information. Galaxy morphology encodes crucial information about galaxy formation history and the physical processes that trigger star formation and AGN activity, and high-resolution imaging for large samples of galaxies is currently only obtainable with HST. The Lockman Hole has been the target of extensive multi-wavelength observations from the X-ray to the radio, and will be the target of the deepest wide-area blankfield thermal IR observations with Herschel, but currently lacks comprehensive HST imaging. We propose to obtain WFPC2 imaging of ~500 arcmin2 of the central region of the Lockman Hole in F606W and F814W, to a depth of V606~26.8 and I814~26. This imaging is crucial in order to characterize the sources detected at other wavelengths.Last Updated: January 16, 2009. B. Blacker |