Evaluation of Contamination and Remediation Manvel Saltwater Disposal Site Brazoria County, Texas

The Manvel Saltwater Disposal (SWD) site (RRC Site No. 92-03-00003), which lies within the city limits of Manvel, Texas, in Brazoria County, was investigated by the Bureau of Economic Geology during a 5-month study from July through November 2015. The study included hydrogeological investigation, waste characterization, assessment of environmental impact, and evaluation of remediation options. Saltwater, drilling waste, and crude oil have been disposed of at the site. There have been several instances of pit overflow, levee rupture, or both, resulting in contamination of the surrounding area by saltwater and crude oil. There have been several public complaints to regulatory agencies, centered on the perceived threat to groundwater quality. The site lies in the outcrop of the Beaumont Formation, where the formation is sufficiently thick to be a local aquifer, containing freshwater with chlorinities of less than 100 mg/L. The Beaumont lies above and is hydrologically distinct from the main water-yielding part of the Chicot aquifer.Bureau of Economic Geolog

Galaxy Peculiar Velocities From Large-Scale Supernova Surveys as a Dark Energy Probe

Upcoming imaging surveys such as the Large Synoptic Survey Telescope will repeatedly scan large areas of sky and have the potential to yield million-supernova catalogs. Type Ia supernovae are excellent standard candles and will provide distance measures that suffice to detect mean pairwise velocities of their host galaxies. We show that when combining these distance measures with photometric redshifts for either the supernovae or their host galaxies, the mean pairwise velocities of the host galaxies will provide a dark energy probe which is competitive with other widely discussed methods. Adding information from this test to type Ia supernova photometric luminosity distances from the same experiment, plus the cosmic microwave background power spectrum from the Planck satellite, improves the Dark Energy Task Force Figure of Merit by a factor of 1.8. Pairwise velocity measurements require no additional observational effort beyond that required to perform the traditional supernova luminosity distance test, but may provide complementary constraints on dark energy parameters and the nature of gravity. Incorporating additional spectroscopic redshift follow-up observations could provide important dark energy constraints from pairwise velocities alone. Mean pairwise velocities are much less sensitive to systematic redshift errors than the luminosity distance test or weak lensing techniques, and also are only mildly affected by systematic evolution of supernova luminosity.Comment: 18 pages; 4 figures; 4 tables; replaced to match the accepted versio

Supervoid Origin of the Cold Spot in the Cosmic Microwave Background

We use a WISE-2MASS-Pan-STARRS1 galaxy catalog to search for a supervoid in the direction of the Cosmic Microwave Background Cold Spot. We obtain photometric redshifts using our multicolor data set to create a tomographic map of the galaxy distribution. The radial density profile centred on the Cold Spot shows a large low density region, extending over 10's of degrees. Motivated by previous Cosmic Microwave Background results, we test for underdensities within two angular radii, $5^\circ$, and $15^\circ$. Our data, combined with an earlier measurement by Granett et al 2010, are consistent with a large $R_{\rm void}=(192 \pm 15)h^{-1} Mpc$ $(2\sigma)$ supervoid with $\delta \simeq -0.13 \pm 0.03$ centered at $z=0.22\pm0.01$. Such a supervoid, constituting a $\sim3.5 \sigma$ fluctuation in the $\Lambda CDM$ model, is a plausible cause for the Cold Spot.Comment: 4 pages, 2 figures, Proceedings of IAU 306 Symposium: Statistical Challenges in 21st Century Cosmolog

Science Objectives and Early Results of the DEEP2 Redshift Survey

The DEIMOS spectrograph has now been installed on the Keck-II telescope and commissioning is nearly complete. The DEEP2 Redshift Survey, which will take approximately 120 nights at the Keck Observatory over a three year period and has been designed to utilize the power of DEIMOS, began in the summer of 2002. The multiplexing power and high efficiency of DEIMOS enables us to target 1000 faint galaxies per clear night. Our goal is to gather high-quality spectra of \~60,000 galaxies with z>0.75 in order to study the properties and large scale clustering of galaxies at z ~ 1. The survey will be executed at high spectral resolution, $R=\lambda/\Delta \lambda \approx 5000$, allowing us to work between the bright OH sky emission lines and to infer linewidths for many of the target galaxies (for several thousand objects, we will obtain rotation curves as well). The linewidth data will facilitate the execution of the classical redshift-volume cosmological test, which can provide a precision measurement of the equation of state of the Universe. This talk reviews the project, summarizes our science goals and presents some early DEIMOS data.Comment: 12 pages, 5 figures, talk presented at SPIE conference, Aug. 200

The DEEP2 Galaxy Redshift Survey: The Evolution of Void Statistics from z~1 to z~0

We present measurements of the void probability function (VPF) at z~1 using data from the DEEP2 Redshift Survey and its evolution to z~0 using data from the Sloan Digital Sky Survey (SDSS). We measure the VPF as a function of galaxy color and luminosity in both surveys and find that it mimics trends displayed in the two-point correlation function, $\xi$; namely that samples of brighter, red galaxies have larger voids (i.e. are more strongly clustered) than fainter, blue galaxies. We also clearly detect evolution in the VPF with cosmic time, with voids being larger in comoving units at z~0. We find that the reduced VPF matches the predictions of a `negative binomial' model for galaxies of all colors, luminosities, and redshifts studied. This model lacks a physical motivation, but produces a simple analytic prediction for sources of any number density and integrated two-point correlation function, \bar{\xi}. This implies that differences in the VPF across different galaxy populations are consistent with being due entirely to differences in the population number density and \bar{\xi}. The robust result that all galaxy populations follow the negative binomial model appears to be due to primarily to the clustering of dark matter halos. The reduced VPF is insensitive to changes in the parameters of the halo occupation distribution, in the sense that halo models with the same \bar{\xi} will produce the same VPF. For the wide range of galaxies studied, the VPF therefore does not appear to provide useful constraints on galaxy evolution models that cannot be gleaned from studies of \bar{\xi} alone. (abridged)Comment: 17 pages, 15 figures, ApJ accepte

Maximum-Likelihood Comparisons of Tully-Fisher and Redshift Data. II. Results from an Expanded Sample

This is the second in a series of papers in which we compare Tully-Fisher (TF) data from the Mark III Catalog with predicted peculiar velocities based on the IRAS galaxy redshift survey and gravitational instability theory, using a rigorous maximum likelihood method called VELMOD. In Paper I (Willick et al. 1997b), we we applied the method to a $cz_{LG} \leq 3000$ km/sec, 838-galaxy TF sample and found $\beta_I=0.49\pm 0.07,$ where $\beta_I\equiv \Omega^{0.6}/b_I$ and $b_I$ is the linear biasing parameter for IRAS galaxies. In this paper we increase the redshift limit to $cz_{LG}=7500$ km/sec, thereby enlarging the sample to 1876 galaxies. The expanded sample now includes the W91PP and CF subsamples of the Mark III catalog, in addition to the A82 and MAT subsamples already considered in Paper I. We implement VELMOD using both the forward and inverse forms of the TF relation, and allow for a more general form of the quadrupole velocity residual detected in Paper I. We find $\beta_I=0.50\pm 0.04$ (1-sigma error) at 300 km/sec smoothing of the IRAS-predicted velocity field. The fit residuals are spatially incoherent for $\beta_I=0.5,$ indicating that the IRAS plus quadrupole velocity field is a good fit to the TF data. If we eliminate the quadrupole we obtain a worse fit, but a similar value for $\beta_I$ of $0.54\pm 0.04.$ Changing the IRAS smoothing scale to 500 km/sec has almost no effect on the best $\beta_I.$ We find evidence for a density-dependence of the small-scale velocity dispersion, $\sigma_v(\delta_g)\simeq (100 + 35 \delta_g)$ km/sec.Comment: Latex, 37 pages, 15 figures, uses modified apjpt4.st