DEIMOS Observations of WISE-Selected, Optically Obscured AGNs

While there are numerous criteria for photometrically identifying active galactic nuclei (AGNs), searches in the optical and UV tend to exclude galaxies that are highly dust obscured. This is problematic for constraining models of AGN evolution and estimating the AGN contribution to the cosmic X-ray and IR backgrounds, as highly obscured objects tend to be underrepresented in large-scale surveys. To address this, we identify potentially obscured AGNs using mid-IR color colors from the Wide-field Infrared Survey Explorer (WISE) catalog. This paper presents the results of optical spectroscopy of obscured AGN candidates using Keck DEIMOS, and their physical properties derived from these spectra. We find that a $W1-W2>0.8$ color criterion effectively selects AGNs with a higher median level of $E(B-V)$ extinction compared to the AGNs found in the SDSS DR7 survey. This optical extinction can be measured using SED modeling or by using $r-W1$ as a measure of optical to IR flux. We find that specific, targeted observations are necessary to find the most highly optically obscured AGNs, and that additional far-IR photometry is necessary to further constrain the dust properties of these AGNs.Comment: 20 pages, 25 figures, accepted by MNRA

Single stage experimental evaluation of variable geometry guide vanes and stators. Part 1 - Analysis and design

Variable geometry concepts applied to guide vanes and stators in single stage compressor

Bedrock geology of the northern Columbia Plateau and adjacent areas

The Columbia Plateau is surrounded by a complex assemblage of highly deformed Precambrian to lower Tertiary continental and oceanic rocks that reflects numerous episodes of continental accretion. The plateau itself is comprised of the Columbia River basalt group formed between about 16.5 x 1 million years B.P. and 6 x 1 million years B.P. Eruptions were infrequent between about 14 and 6 x 1 million years B.P., allowing time for erosion and deformation between successive outpourings. The present-day courses of much of the Snake River, and parts of the Columbia River, across the plateau date from this time. Basalt produced during this waning activity is more heterogeneous chemically and isotopically than older flows, reflecting its prolonged period of volcanism

Coulomb Distortion Effects for Electron or Positron Induced (e,e′)(e,e') Reactions in the Quasielastic Region

In response to recent experimental studies we investigate Coulomb distortion effects on $(e,e')$ reactions from medium and heavy nuclei for the case of electrons and positrons. We extend our previously reported full DWBA treatment of Coulomb distortions to the case of positrons for the $^{208}Pb(e,e')$ reaction in the quasielastic region for a particular nuclear model. In addition, we use previously reported successful approaches to treating Coulomb corrections in an approximate way to calculate the Coulomb distortion effects for $(e,e')$ reactions for both electrons and positrons for the case of a simple nuclear model for quasielastic knock-out of nucleons. With these results in hand we develop a simple {\em ad-hoc} approximation for use in analyzing experiments, and discuss methods of extracting the ``longitudinal structure function" which enters into evaluation of the Coulomb sum rule. These techniques are generally valid for lepton induced reactions on nuclei with momentum transfers greater than approximately 300 $MeV/c$.Comment: 18 pages, 6 figure

The Burundi Heart Centre: From concept to design.

Burundi is one of the worlds poorest nations, which is also reflected in its relative lack of cardiac facilities, particularly those catering to young children and adults. The authors discuss current efforts to build The Burundi Heart Centre to help address this challenge. In particular, they highlight how the project can act as a case study for a sustainable architecture that involves local people and uses locally available materials in a contemporary and innovative way

A solvable model of the evolutionary loop

A model for the evolution of a finite population in a rugged fitness landscape is introduced and solved. The population is trapped in an evolutionary loop, alternating periods of stasis to periods in which it performs adaptive walks. The dependence of the average rarity of the population (a quantity related to the fitness of the most adapted individual) and of the duration of stases on population size and mutation rate is calculated.Comment: 6 pages, EuroLaTeX, 1 figur

Effective Temperature Of Uranus

NASA NGR 09-015-047, NGR 22-007-270, NGR 44-012-152Astronom