Proposal letter regarding the Sloan Disgital SKy Survey

Kent, Stevens ; Kron, Richard

Fermi National Accelerator Laboratory

关键词: Nonluminous Matter;    Quasars;    Supernovae;    Computers;    43 Particle Accelerators;   

DOI  :  10.2172/912646
RP-ID  :  FERMILAB-PROPOSAL-0949
RP-ID  :  AC02-07CH11359
RP-ID  :  912646

美国|英语

来源: UNT Digital Library

【 摘 要 】

We would like to propose that Fermilab participate in a three-year extension of operations of the Sloan Digital Sky Survey (SDSS). The SDSS has already provided a wealth of new information about astrophysical and cosmological phenomena, ranging from discoveries of some of the lowest mass stars near the sun to the most distant known quasars. Fermilab scientists have authored or coauthored numerous papers on topics such as the discovery of new structures in the Milky Way halo and detailed studies of galaxy clustering. The detection of the ''shadow of dark energy'' last year by the SDSS shared honors with results from the WMAP satellite as the Discovery of the Year by Science Magazine. Fermilab has had a pivotal role in the creation of the SDSS project and the construction of the data archive, which has already become a valuable resource to the scientific community and to the general public at large. By June of 2005, the SDSS will have completed its nominal five-year period of operations. There is a strong desire among many of the existing SDSS collaborators, including Fermilab, to pursue a three-year extension of operations, both to complete an unfinished portion of the survey area and to pursue new science programs inspired by the discoveries of the current survey. The extension is composed of three science programs that can share the observing time around the year. At the end of our five year program, the SDSS will have surveyed two large but disconnected regions of sky in the North Galactic cap, leaving one of the original goals of the survey uncompleted: to have surveyed a complete filled volume of the universe. The reason for the gap between these two regions is that the rate of collecting data was simply less than anticipated, largely due to the impact of weather conditions at the site. Thus, there is a desire to fill in the gap. The discovery of new structures in the Milky Way halo, coupled with the realization that the SDSS is an ideal instrument for probing these structures, has led to the development of a program called SEGUE--the Sloan Extension for Galactic Underpinnings and Evolution. This program will survey the sky in areas not included in the original plan and will pursue a multitude of questions regarding the formation of the Milky Way galaxy, including the role and impact of Dark Matter that seems to dominate its mass. The SDSS 2.5 meter telescope is well suited for surveying and detecting supernovae (SNe) in the redshift range 0.1 to 0.3, a range poorly covered by today's existing SNe surveys. Such data are important for determining the expansion rate of the nearby universe and are essential for interpreting data at high redshift from current and future space-based surveys such as the SNAP experiment that is being proposed for the NASA/DOE Joint Dark Energy Mission and of which several Fermilab scientists (many of whom are on this proposal) are already members. Fermilab scientists are extremely interested in all three of the core science goals of the extension. No major new hardware systems are needed, allowing us to take advantage of the existing infrastructure at the Apache Point Observatory (APO) in New Mexico. Only modest changes or enhancements are needed to the data processing systems. The data acquisition system will likely require upgrading to replace the oldest computers that are no longer under warranty. A new data processing system at APO will be needed to process the supernova survey data in near-realtime.