Rates for Color Shifted Microlensing Events

If the objects responsible for gravitational microlensing (ML) of Galactic-bulge stars are faint dwarfs, then blended light from the lens will distort the shape of the ML light curve and shift the color of the observed star during the event. The resolution in current surveys is not accurate enough to observe this effect, but it should be detected with frequent and precise followup observations. We calculate the expected rates for ML events where the shape distortions will be observable by such followup observations, assuming that the lenses are ordinary main-sequence stars in a bar and in the disk. We study the dependence of the rates for color-shifted (CS) events on the frequency of followup observations and on the precision of the photometry for a variety of waveband pairings. We find that for hourly observations in $B$ and $K$ with typical photometric errors of 0.01 mag, 28\% of the events where a main-sequence bulge star is lensed, and 7\% of the events where the source is a bulge giant, will give rise to a measurable CS at the 95\% confidence level. For observations in $V$ and $I$, the fractions become 18\% and 5\%, respectively, but may be increased to 40\% and 13\% by improved photometric accuracy and increased sampling frequency. We outline how the mass, distance, and transverse speed of the lens can be obtained, giving examples of typical errors. We discuss how CS events can be distinguished from events where the source is blended with a binary companion.Comment: 36 pages, uuencoded postscript fil

An Evaluation of Physical Disk I/Os for Complex Object Processing

In order to obtain the performance required for nonstandard database environments, a hierarchical complex object model with object references is used as a storage structure for complex objects. Several storage models for these complex objects, as well as a benchmark to evaluate their performance, are described. A cost model for analytical performance evaluation is developed, and the analytical results are validated by means of measurements on the DASDBS, complex object storage system. The results show which storage structures for complex objects are the most efficient under which circumstance

The DELTA MONSTER: An RPV designed to investigate the aerodynamics of a delta wing platform

The mission requirements for the performance of aerodynamic tests on a delta wind planform posed some problems, these include aerodynamic interference; structural support; data acquisition and transmission instrumentation; aircraft stability and control; and propulsion implementation. To eliminate the problems of wall interference, free stream turbulence, and the difficulty of achieving dynamic similarity between the test and actual flight aircraft that are associated with aerodynamic testing in wind tunnels, the concept of the remotely piloted vehicle which can perform a basic aerodynamic study on a delta wing was the main objective for the Green Mission - the Delta Monster. The basic aerodynamic studies were performed on a delta wing with a sweep angle greater than 45 degrees. These tests were performed at various angles of attack and Reynolds numbers. The delta wing was instrumented to determine the primary leading edge vortex formation and location, using pressure measurements and/or flow visualization. A data acquisition system was provided to collect all necessary data

Detection of Ly\beta auto-correlations and Ly\alpha-Ly\beta cross-correlations in BOSS Data Release 9

The Lyman-$\beta$ forest refers to a region in the spectra of distant quasars that lies between the rest-frame Lyman-$\beta$ and Lyman-$\gamma$ emissions. The forest in this region is dominated by a combination of absorption due to resonant Ly$\alpha$ and Ly$\beta$ scattering. When considering the 1D Ly$\beta$ forest in addition to the 1D Ly$\alpha$ forest, the full statistical description of the data requires four 1D power spectra: Ly$\alpha$ and Ly$\beta$ auto-power spectra and the Ly$\alpha$-Ly$\beta$ real and imaginary cross-power spectra. We describe how these can be measured using an optimal quadratic estimator that naturally disentangles Ly$\alpha$ and Ly$\beta$ contributions. Using a sample of approximately 60,000 quasar sight-lines from the BOSS Data Release 9, we make the measurement of the one-dimensional power spectrum of fluctuations due to the Ly$\beta$ resonant scattering. While we have not corrected our measurements for resolution damping of the power and other systematic effects carefully enough to use them for cosmological constraints, we can robustly conclude the following: i) Ly$\beta$ power spectrum and Ly$\alpha$-Ly$\beta$ cross spectra are detected with high statistical significance; ii) the cross-correlation coefficient is $\approx 1$ on large scales; iii) the Ly$\beta$ measurements are contaminated by the associated OVI absorption, which is analogous to the SiIII contamination of the Ly$\alpha$ forest. Measurements of the Ly$\beta$ forest will allow extension of the usable path-length for the Ly$\alpha$ measurements while allowing a better understanding of the physics of intergalactic medium and thus more robust cosmological constraints.Comment: 26 pages, 10 figures; matches version accepted by JCA

New approach for precise computation of Lyman-alpha forest power spectrum with hydrodynamical simulations

Current experiments are providing measurements of the flux power spectrum from the Lyman-α forests observed in quasar spectra with unprecedented accuracy. Their interpretation in terms of cosmological constraints requires specific simulations of at least equivalent precision. In this paper, we present a suite of cosmological N-body simulations with cold dark matter and baryons, specifically aiming at modeling the low-density regions of the inter-galactic medium as probed by the Lyman-α forests at high redshift. The simulations were run using the GADGET-3 code and were designed to match the requirements imposed by the quality of the current SDSS-III/BOSS or forthcoming SDSS-IV/eBOSS data. They are made using either 2 × 7683 1 billion or 2 × 1923 14 million particles, spanning volumes ranging from (25 Mpc h−1)3 for high-resolution simulations to (100 Mpc h−1)3 for large-volume ones. Using a splicing technique, the resolution is further enhanced to reach the equivalent of simulations with 2 × 30723 58 billion particles in a (100 Mpc h−1)3 box size, i.e. a mean mass per gas particle of 1.2 × 105M⊙ h−1. We show that the resulting power spectrum is accurate at the 2% level over the full range from a few Mpc to several tens of Mpc. We explore the effect on the one-dimensional transmitted-flux power spectrum of four cosmological parameters (ns, σ8, Ωm and H0) and two astrophysical parameters (T0 and γ) that are related to the heating rate of the intergalactic medium. By varying the input parameters around a central model chosen to be in agreement with the latest Planck results, we built a grid of simulations that allows the study of the impact on the flux power spectrum of these six relevant parameters. We improve upon previous studies by not only measuring the effect of each parameter individually, but also probing the impact of the simultaneous variation of each pair of parameters. We thus provide a full second-order expansion, including cross-terms, around our central model. We check the validity of the second-order expansion with independent simulations obtained either with different cosmological parameters or different seeds. Finally, a comparison to the one-dimensional Lyman-α forest power spectrum obtained with BOSS by [1] shows an excellent agreement

The Ursinus Weekly, May 14, 1970

Skytop hosts annual student, Board talks • Students mount war protests; March against Cambodia, Kent • ProTheatre productions • Evolution lecturer • Pre-professional societies elect 1970-71 officers • Editorial: Kent State massacre: an American tragedy • Focus: Barrie Doan • The strike • From the other side: In the midst of change • 1970 Ursinus Ruby drowning in red ink • In my opinion: Everything is beautiful • Letters to the editor: Ur Sin us College; House-mother • Trackmen edged in MAC finals • Batmen grab lone victory • Bearettes whip Rams in softball, lacrosse • Howard\u27s netmen set 7-4-1 modern mark • Final examination schedulehttps://digitalcommons.ursinus.edu/weekly/1160/thumbnail.jp

Clinical and molecular genetic features of pulmonary hypertension in patients with hereditary hemorrhagic telangiectasia

BACKGROUND: Most patients with familial primary pulmonary hypertension have defects in the gene for bone morphogenetic protein receptor II (BMPR2), a member of the transforming growth factor beta (TGF-beta) superfamily of receptors. Because patients with hereditary hemorrhagic telangiectasia may have lung disease that is indistinguishable from primary pulmonary hypertension, we investigated the genetic basis of lung disease in these patients. METHODS: We evaluated members of five kindreds plus one individual patient with hereditary hemorrhagic telangiectasia and identified 10 cases of pulmonary hypertension. In the two largest families, we used microsatellite markers to test for linkage to genes encoding TGF-beta-receptor proteins, including endoglin and activin-receptor-like kinase 1 (ALK1), and BMPR2. In subjects with hereditary hemorrhagic telangiectasia and pulmonary hypertension, we also scanned ALK1 and BMPR2 for mutations. RESULTS: We identified suggestive linkage of pulmonary hypertension with hereditary hemorrhagic telangiectasia on chromosome 12q13, a region that includes ALK1. We identified amino acid changes in activin-receptor-like kinase 1 that were inherited in subjects who had a disorder with clinical and histologic features indistinguishable from those of primary pulmonary hypertension. Immunohistochemical analysis in four subjects and one control showed pulmonary vascular endothelial expression of activin-receptor-like kinase 1 in normal and diseased pulmonary arteries. CONCLUSIONS: Pulmonary hypertension in association with hereditary hemorrhagic telangiectasia can involve mutations in ALK1. These mutations are associated with diverse effects, including the vascular dilatation characteristic of hereditary hemorrhagic telangiectasia and the occlusion of small pulmonary arteries that is typical of primary pulmonary hypertension

The Ursinus Weekly, May 28, 1970

Alan Gold, Weekly win press awards • Carol Haas, Ed Leinbach win in ISC • Brooks Hays selected speaker at graduation for 289 UC seniors • 1970 C.C.C. promises new approach to frosh • Three profs hired • Students pass Bill; Negotiations ensue • Editorial: Year of involvement • Focus: Larry Saunders • Letters to the editor: Publicly passionate; Maples patriots; Girl ratings • Eight faculty leave Ursinus • Students, administration, Board members discuss students rights at Skytop • Woodstock arrives on screen • Wind blown • From the other side: An exercise in contradiction • Contemplations: An apology • Summer reading program • 300 fete Eleanor Snell; Former Snellbelles present • Batmen finish dismal season; Outlook excellent for 1971 • Win over Albright caps tennis season • Cricket victory • A very good year for U.C. athletics • In the wake of Earth Day • Ursinus moviemakers explore daring field • Protest • Octogenarians get with ithttps://digitalcommons.ursinus.edu/weekly/1161/thumbnail.jp