We report results of a direct imaging survey for giant planets around 80 members of the beta Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra moving groups, observed as part of the ...Gemini/NICI Planet-Finding Campaign. We found numerous (>70) candidate companions in our survey images. Some of these candidates were rejected as common-proper motion companions using archival data; we reobserved with Near-Infrared Coronagraphic Imager (NICI) all other candidates that lay within 400 AU of the star and were not in dense stellar fields. The vast majority of candidate companions were confirmed as background objects from archival observations and/or dedicated NICI Campaign followup. Our results strongly constrain the frequency of planets within semi-major axes of 50 AU as well. We restrict the frequency of 1-20 M sub(Jup) companions at semi-major axes from 10-50 AU to <21% at a 95.4% confidence level using DUSTY models and to <7% at a 95.4% using COND models.
Abstract
We analyse the anisotropic clustering of massive galaxies from the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 9 (DR9) sample, which consists of ...264 283 galaxies in the redshift range 0.43 < z < 0.7 spanning 3275 deg2. Both peculiar velocities and errors in the assumed redshift-distance relation ('Alcock-Paczynski effect') generate correlations between clustering amplitude and orientation with respect to the line of sight. Together with the sharp baryon acoustic oscillation (BAO) standard ruler, our measurements of the broad-band shape of the monopole and quadrupole correlation functions simultaneously constrain the comoving angular diameter distance (2190 ± 61 Mpc) to z = 0.57, the Hubble expansion rate at z = 0.57 (92.4 ± 4.5 km s−1 Mpc−1) and the growth rate of structure at that same redshift (dσ8/d ln a = 0.43 ± 0.069). Our analysis provides the best current direct determination of both D
A and H in galaxy clustering data using this technique. If we further assume a Λcold dark matter expansion history, our growth constraint tightens to dσ8/d ln a = 0.415 ± 0.034. In combination with the cosmic microwave background, our measurements of D
A, H and dσ8/d ln a all separately require dark energy at z > 0.57, and when combined imply ΩΛ = 0.74 ± 0.016, independent of the Universe's evolution at z < 0.57. All of these constraints assume scale-independent linear growth, and assume general relativity to compute both (10 per cent) non-linear model corrections and our errors. In our companion paper, Samushia et al., we explore further cosmological implications of these observations.
•A multidimensional definition of diversity informed teacher educators' work.•There was greater acceptance for diversity in participants' professional contexts.•Participants associated diversity with ...demographic shifts and immigration.•The study highlights tensions in sharing and enacting beliefs about diversity.
Although the U.S. economy of the early twenty-first century is vastly different from the U.S. economy prior to the 1970s, the nature of these economic changes and their impact on U.S. workers is ...unclear. This article claims that despite contemporary economic shifts, differential labor and employer power continues to segment the economy, and workers' position in the labor market continues to predict their rewards, beyond the effects of gender, race, and human capital. Drawing on segmented labor market and dual economy research, we propose a four-category model of the structural factors that influence variance in work-related rewards. We examine the distribution of jobs in each of four categories between 1974 and 2000 and observe that losses and gains across categories are unevenly distributed by race and gender. While white men have experienced the greatest declines in employment and earnings, they have maintained their absolute advantage over women and nonwhites. In multivariate analyses, we find that the structural position of employment continues to be a significant determinant of wages. Although women and racial minorities have experienced sizable increases in employment in primary labor market jobs in the core of the economy, both groups remain overrepresented in low-paying jobs. Moreover women, but not nonwhite men, consistently receive significantly fewer rewards for their labor in both low-paying and high-paying jobs. Our findings suggest that structural factors continue to influence earnings inequality, especially across race and gender lines.
The nontrivial relationship between observations of galaxy positions in redshift space and the underlying matter field complicates our ability to determine the linear theory power spectrum and ...extract cosmological information from galaxy surveys. The Sloan Digital Sky Survey (SDSS) luminous red galaxy (LRG) catalog has the potential to place powerful constraints on cosmological parameters. LRGs are bright, highly biased tracers of large-scale structure. However, because they are highly biased, the nonlinear contribution of satellite galaxies to the galaxy power spectrum is large and fingers-of-God (FOGs) are significant. The combination of these effects leads to a ~10% correction in the underlying power spectrum at k = 0.1 h Mpc-1 and ~40% correction at k = 0.2 h Mpc-1 in the LRG P(k) analysis of Tegmark et al., thereby compromising the cosmological constraints when this potentially large correction is left as a free parameter. We propose an alternative approach to recovering the matter field from galaxy observations. Our approach is to use halos rather than galaxies to trace the underlying mass distribution. We identify FOGs and replace each FOG with a single halo object. This removes the nonlinear contribution of satellite galaxies, the one-halo term. We test our method on a large set of high-fidelity mock SDSS LRG catalogs and find that the power spectrum of the reconstructed halo density field deviates from the underlying matter power spectrum at the <=1% level for k <= 0.1 h Mpc-1 and <=4% at k = 0.2 h Mpc-1. The reconstructed halo density field also removes the bias in the measurement of the redshift space distortion parameter Delta *b induced by the FOG smearing of the linear redshift space distortions.
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