An exciting benefit of the semiconductor revolution that has had tremendous impact on astronomy at optical and infrared wavelengths has been the development of ever more sensitive array detectors. These arrays are delivering hitherto-unimagined improvements in observing efficiency and enabling new and exciting science projects. This project plans to carry out an upgrade to the array detector in the OSIRIS instrument deployed on the 10 meter Keck telescope on top of Mauna Kea. The current science detector, called a Hawaii-2 (H2), will be replaced with a Hawaii-2RG (H2RG), which has a number of technical features that significantly enhance its performance.
The OSIRIS instrument is an integral-field spectrograph (IFS) fed by adaptive optics (AO); there are only a few such combinations in operation worldwide at the moment. The non-common-path error is low, less than any other IFS, preserving the diffraction-limited point-spread-function delivered by the Keck AO system. This has been a very productive combination scientifically. The older array detector may be at some risk for failure simply due to its age; the newer array will offer higher sensitivity (twice as high at many wavelengths) and reduced detector artifacts. It will have improved multiplexer performance that will greatly reduce channel-to-channel crosstalk and eliminate a reset anomaly that degrades some of the readouts in a commonly-used mode of observing.
The Keck telescopes have had a major impact on astronomy education, as evidenced by the 240 PhD theses (now averaging 20/year) produced as of early 2012 using Keck data. Many leaders in U.S. astronomy are included in this number. The WMKO (Keck Observatory) provides many graduate students and post-doctoral fellows direct access to state-of-the-art instrumentation, including adaptive optics. The OSIRIS upgrade project in particular will involve a graduate student at UCLA.
Funding for this project is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.
