Redshifts and Neutral Hydrogen Observations of Compact Symmetric Objects in the COINS Sample

Compact Symmetric Objects (CSOs) are young radio galaxies whose jet axes lie close to the plane of the sky, and whose appearance is therefore not dominated by relativistic beaming effects. The small linear sizes of CSOs make them valuable for studies of both the evolution of radio galaxies and testing unified schemes for active galactic nuclei (AGN). A parsec-scale region of gas surrounding the central engine is predicted by both accretion and obscuration scenarios. Working surfaces, or ``hot spots,'' and the radio jets of CSOs are close enough to the central engines that this circumnuclear gas can be seen in absorption. The CSOs Observed in the Northern Sky (COINS) sample is comprised of 52 CSO candidates identified in three VLBI surveys. Of these, 27 have now been confirmed as CSOs. Optical redshifts are available in the literature for 28 of the CSO candidates, and HI absorption has been detected toward four. We present new optical spectroscopic redshifts for three of the candidates and summarize the current status of optical identifications. We further report on the discovery of HI in absorption towards the CSO J1816+3457 and summarize the results of neutral hydrogen absorption studies of the sources in this sample.Comment: 12 pages, Accepted for publication in Ap

OPPORTUNITY COSTS OF WATER LEASING: IRRIGATION, INSTREAM FLOW, AND WETLAND CONSIDERATIONS IN THE LARAMIE BASIN, WYOMING

Flood irrigation in the Laramie Basin of southeast Wyoming has created many wetlands that rely directly on irrigation inputs for water. The Laramie Basin is a proposed water source for enhancing Platte River instream flows, to the benefit of endangered cranes, terns, plovers, and sturgeons. Increasing irrigation efficiency, or retiring irrigated lands would transform Laramie Basin agriculture and cause a high fraction of the Basins wetlands to be lost. This study explores the limitations of traditional water transfer tools when regional instream-flow requirements compete for water with local irrigation-dependent wetlands. A rotating short-term water lease program is proposed. The program would allow Laramie Basin producers to contribute to instream flow without causing permanent wetland damage or loss. Short-term water leasing programs could allow agricultural communities to contribute to regional environmental water needs without sacrificing local, agriculturally-based ecological resources. An estimate of minimum water costs, advantages and disadvantages of short-term water leasing are discussed.Resource /Energy Economics and Policy,

An Evaluation Use Framework and Empirical Assessment

Background: Research on evaluation use focuses on putting evaluation recommendations into practice. Prior theoretical research proposes varied frameworks for understanding the use (or lack) of program evaluation results.   Purpose: Our purpose is to create and test a single, integrated framework for understanding evaluation use. This article relies on prior theoretical research regarding categories of utilization, typologies of recommendations, and factors affecting utilization to frame an empirical study of evaluation use that then tests the integrated theory.   Setting: The empirical part of the article draws on post-evaluation interviews with sixteen agencies that have engaged in evaluation research.   Subjects: The agencies are mostly local non-profits, but the sample also includes a state agency, a city agency, and two university-community partnerships. All agencies had undergone a program evaluation between 2003 and 2006.   Intervention: Having participated in an evaluation is the main “intervention” of interest in this article, in which we consider the relationship between evaluation use theory and empirical evidence on the topic.   Research Design: A qualitative approach, our research design involved examining each of the sixteen agencies within two years of their having been evaluated.   Data Collection and Analysis: Data collection included structured in-person interviews with at least one key informant in each agency. In addition, a short, closed-ended survey was administered to research participants. Interview data were analyzed using content analysis of themes and grouping agencies according to their evaluation’s outcomes (favorable or not) and experiences. Survey data were analyzed with simple descriptive statistics and similarly involved a subgroup analysis, according to agencies’ reported use of evaluation.   Findings: Most evaluation use is conceptual, and few agencies studied actually implemented specific evaluation recommendations. Agencies perceived recommendations as changes to rules and structure, which theory and prior research suggest suppresses use. An important human factor that influenced evaluation use was minimal post-evaluation interaction with evaluators. Some long-term influence of the evaluation is evident, but only as conceptual and not as instrumental. In fact, very little instrumental use existed in this empirical assessment.   Conclusions: Evidence suggests that evaluation use in practice aligns with theory, specifically emphasizing the conceptual use dimension. The proposed integrated model of prior evaluation use theories may hold value for future theoretical and empirical work

The joint US/UK 1990 epoch world magnetic model

A detailed summary of the data used, analyses performed, modeling techniques employed, and results obtained in the course of the 1990 Epoch World Magnetic Modeling effort are given. Also, use and limitations of the GEOMAG algorithm are presented. Charts and tables related to the 1990 World Magnetic Model (WMM-90) for the Earth's main field and secular variation in Mercator and polar stereographic projections are presented along with useful tables of several magnetic field components and their secular variation on a 5-degree worldwide grid

Obscuration of the Parsec Scale Jets in the Compact Symmetric Object 1946+708

We present results of VLA and VLBA observations of the 1.420 GHz neutral hydrogen absorption associated with the Compact Symmetric Object 1946+708 (z=0.101). We find significant structure in the gas on parsec scales. The peak column density in the HI (N_HI~2.2x10^23 cm^-2 (T_s/8000K)) occurs toward the center of activity of the source, as does the highest velocity dispersion (FWHM~350 \kms). In addition, we find that the continuum spectra of the various radio components associated with these jets strongly indicate free-free absorption. This effect is particularly pronounced toward the core and inner components of the receding jet, suggesting the presence of a screen local to the source, perhaps part of an obscuring torus.Comment: revised version, some text added, 1 figure changed; accepted to Astrophysical Journal, 22 page LaTeX document includes 8 postscript figure

New Limits on Local Lorentz Invariance in Mercury and Cesium

We report new bounds on Local Lorentz Invariance (LLI) violation in Cs and Hg. The limits are obtained through the observation of the the spin- precession frequencies of 199Hg and 133Cs atoms in their ground states as a function of the orientation of an applied magnetic field with respect to the fixed stars. We measure the amplitudes of the dipole couplings to a preferred direction in the equatorial plane to be 19(11) nHz for Hg and 9(5) microHz for Cs. The upper bounds established here improve upon previous bounds by about a factor of four. The improvement is primarily due to mounting the apparatus on a rotating table. New bounds are established on several terms in the standard model extension including the first bounds on the spin-couplings of the neutron and proton to the z direction, <7e-30 GeV and <7e-29 GeV, respectively.Comment: 17 pages, 6 figure

HI Observations of the Supermassive Binary Black Hole System in 0402+379

We have recently discovered a supermassive binary black hole system with a projected separation between the two black holes of 7.3 parsecs in the radio galaxy 0402+379. This is the most compact supermassive binary black hole pair yet imaged by more than two orders of magnitude. We present Global VLBI observations at 1.3464 GHz of this radio galaxy, taken to improve the quality of the HI data. Two absorption lines are found toward the southern jet of the source, one redshifted by 370 +/- 10 km/s and the other blueshifted by 700 +/- 10 km/s with respect to the systemic velocity of the source, which, along with the results obtained for the opacity distribution over the source, suggests the presence of two mass clumps rotating around the central region of the source. We propose a model consisting of a geometrically thick disk, of which we only see a couple of clumps, that reproduces the velocities measured from the HI absorption profiles. These clumps rotate in circular Keplerian orbits around an axis that crosses one of the supermassive black holes of the binary system in 0402+379. We find an upper limit for the inclination angle of the twin jets of the source to the line of sight of 66 degrees, which, according to the proposed model, implies a lower limit on the central mass of ~7 x 10^8 Msun and a lower limit for the scale height of the thick disk of ~12 pc .Comment: 20 pages, 7 figures. Accepted on the Astrophysical Journa