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Cosmology and Astrophysics - SDSS
The Sloan Digital Sky Survey (SDSS) is the largest spectroscopic
survey ever undertaken. The SDSS will be the key datasource of
cosmological structure for the next two decades. It combines
optical imaging and spectroscopy, tracking nearby asteroids
to distant quasars, using a 2.5m telescope located in New
Mexico. Imaging data is obtained with a wide-field camera; the data
are automatically processed and selected objects are targeted for
spectroscopy. Depth information from galactic redshifts are used to
make a 3-D map. The SDSS will have images from over 100 million
objects, including more than a hundred thousand quasars, and spectra
from a million galaxies. The second phase, SDSS-II, has began in fall
2005 with two additions to the original Legacy Survey. The Sloan
Extension for Galactic Underpinning and Evolution (SEGUE) targets
stars in the Galaxy, and the Sloan Supernova Survey observes
supernovae at high redshift. LANL has been an SDSS associate member
since 2001 and is a full member of SDSS-II.
Research areas pursued at LANL include the SEGUE Open Cluster Survey
(SOCS) and studies of star formation. One of my major projects is the
determination of cosmological parameters from the Lyman-alpha forest
measured from 6,000 SDSS quasars at high redshift. Together with
Salman Habib (T-8), Lam Hui (Columbia), Adam Lidz (Harvard), Michael
Rauch (Carnegie), and Wallace Sargent (Caltech) we have developed a
new approach to constrain the amplitude and slope of the mass power
spectrum. This new approach, which is based on measuring the one-point
probability distribution function, allows us to obtain tight
constrains on cosmological parameters from the SDSS quasar
spectra. The picture is in the upper left corner shows myself in the
SDSS mirror. |
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