C. W. Stubbs

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The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of the distribution of luminous and non-luminous matter in the Universe: a photometrically and astrometrically calibrated digital imaging survey of π steradians above about Galactic latitude 30◦ in five broad optical bands to a depth of g′ ∼ 23, and a spectroscopic(More)
We present constraints on the dark energy equation-of-state parameter, w = P/(ρc), using 60 Type Ia supernovae (SNe Ia) from the ESSENCE supernova survey. We derive a set of constraints on the nature of the dark energy assuming a flat Universe. By including constraints on (ΩM, w) from baryon acoustic oscillations, we obtain a value for a static(More)
The High-z Supernova Search Team has discovered and observed 8 new supernovae in the redshift interval z = 0.3–1.2. These independent observations, analyzed by similar but distinct methods, confirm the result of Riess et al. (1998a) and Perlmutter et al. (1999) that supernova luminosity distances imply an accelerating universe. More importantly, they extend(More)
The High-Z Supernova Search is an international collaboration to discover and monitor type Ia supernovae (SN Ia) at z > 0.2 with the aim of measuring cosmic deceleration and global curvature. Our collaboration has pursued a basic understanding of supernovae in the nearby Universe, discovering and observing a large sample of objects, and developing methods(More)
Quantification of Margins and Uncertainties is a formalism for dealing with the reliability of complex technical systems, and the confidence which can be placed in estimates of that reliability. We are specifically concerned with its application to the performance and safety of the nuclear stockpile, because the test moratorium precludes direct experimental(More)
National Optical Astronomy Observatory, 950 N. Cherry Ave, Tucson, AZ 85719 Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 Physics Department, University of California, One Shields Avenue, Davis, CA 95616 Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 U.S. Naval Observatory Flagstaff Station,(More)
In the course of its commissioning observations, the Sloan Digital Sky Survey (SDSS) has produced one of the largest redshift samples of galaxies selected from CCD images. Using 11,275 galaxies complete to r∗ = 17.6 over 140 square degrees, we compute the luminosity function of galaxies in the r∗ band over a range −23 < Mr∗ < −16 (for h = 1). The result is(More)
We present photometric and spectroscopic observations of 23 high redshift supernovae spanning a range of z = 0.34 − 1.03, 9 of which are unambiguously classified as Type Ia. These supernovae were discovered during the IfA Deep Survey, which began in September 2001 and observed a total of 2.5 square degrees to a depth of approximately m ≈ 25− 26 in RIZ over(More)
We report the detection of 45 candidate microlensing events in fields toward the Galactic bulge. These come from the analysis of 24 fields containing 12.6 million stars observed for 190 days in 1993. Many of these events are of extremely high signal to noise and are remarkable examples of gravitational microlensing. The distribution of peak magnifications(More)
We present constraints on violations of Lorentz invariance based on archival lunar laser-ranging (LLR) data. LLR measures the Earth-Moon separation by timing the round-trip travel of light between the two bodies and is currently accurate to the equivalent of a few centimeters (parts in 10(11) of the total distance). By analyzing this LLR data under the(More)