131 research outputs found

    A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: The Group Catalog

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    With a large, unique spectroscopic survey in the fields of 28 galaxy-scale strong gravitational lenses, we identify groups of galaxies in the 26 adequately-sampled fields. Using a group finding algorithm, we find 210 groups with at least five member galaxies; the median number of members is eight. Our sample spans redshifts of 0.04 zgrp\le z_{grp} \le 0.76 with a median of 0.31, including 174 groups with 0.1<zgrp<0.60.1 < z_{grp} < 0.6. Groups have radial velocity dispersions of 60 σgrp\le \sigma_{grp} \le 1200 km s1^{-1} with a median of 350 km s1^{-1}. We also discover a supergroup in field B0712+472 at z=z = 0.29 consisting of three main groups. We recover groups similar to \sim 85% of those previously reported in these fields within our redshift range of sensitivity and find 187 new groups with at least five members. The properties of our group catalog, specifically 1) the distribution of σgrp\sigma_{grp}, 2) the fraction of all sample galaxies that are group members, and 3) the fraction of groups with significant substructure, are consistent with those for other catalogs. The distribution of group virial masses agrees well with theoretical expectations. Of the lens galaxies, 12 of 26 (46%) (B1422+231, B1600+434, B2114+022, FBQS J0951+2635, HE0435-1223, HST J14113+5211, MG0751+2716, MGJ1654+1346, PG 1115+080, Q ER 0047-2808, RXJ1131-1231, and WFI J2033-4723) are members of groups with at least five galaxies, and one more (B0712+472) belongs to an additional, visually identified group candidate. There are groups not associated with the lens that still are likely to affect the lens model; in six of 25 (24%) fields (excluding the supergroup), there is at least one massive (σgrp\sigma_{grp} \ge 500 km s1^{-1}) group or group candidate projected within 2^{\prime} of the lens.Comment: 87 pages, 8 figures, a version of this was published in Ap

    Kinesitherapy for Patients on Hemodialysis

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    Introduction: Chronic kidney disease (CKD) is a huge challenge for GPs and nephrologists. Physiotherapists are increasingly included in the multidisciplinary teams dealing with CKD around the world to improve the quality of life and prevent a number of complications of patients undergoing the most common treatment for CKD, namely hemodialysis.Aim: The aim of this article is to present the possibilities for optimizing and supporting the motor activity of hemodialysis patients.Materials and Methods: Review of medical literature from the last 10 years, published in the scientific databases: Pubmed, Google Scholar, PubMed Central, and ScienceDirect, has been conducted.Results: Numerous independent studies have shown that kinesitherapy is a reliable aid in the prevention of cardiovascular diseases and in improving the overall condition of patients with CKD on hemodialysis. The implementation of specialized devices for kinesitherapy during hemodialysis and the selection of appropriate exercises to practice at home also show a significant improvement in mental health (motivation for a better and more active life) of hemodialysis patients.Conclusion: The inclusion of kinesitherapy during hemodialysis and acquainting chronically ill patients with the opportunities for improving their physical activities would lead to improved health status and quality of life of these patients

    The H-alpha Luminosity Function and Star Formation Rate Volume Density at z=0.8 from the NEWFIRM H-alpha Survey

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    [Abridged] We present new measurements of the H-alpha luminosity function (LF) and SFR volume density for galaxies at z~0.8. Our analysis is based on 1.18μ\mum narrowband data from the NEWFIRM H-alpha Survey, a comprehensive program designed to capture deep samples of intermediate redshift emission-line galaxies using narrowband imaging in the near-infrared. The combination of depth (1.9×1017\approx1.9\times10^{-17} erg s1^{-1} cm2^{-2} in H-alpha at 3σ\sigma) and areal coverage (0.82 deg2^2) complements other recent H-alpha studies at similar redshifts, and enables us to minimize the impact of cosmic variance and place robust constraints on the shape of the LF. The present sample contains 818 NB118 excess objects, 394 of which are selected as H-alpha emitters. Optical spectroscopy has been obtained for 62% of the NB118 excess objects. Empirical optical broadband color classification is used to sort the remainder of the sample. A comparison of the LFs constructed for the four individual fields reveals significant cosmic variance, emphasizing that multiple, widely separated observations are required. The dust-corrected LF is well-described by a Schechter function with L*=10^{43.00\pm0.52} ergs s^{-1}, \phi*=10^{-3.20\pm0.54} Mpc^{-3}, and \alpha=-1.6\pm0.19. We compare our H-alpha LF and SFR density to those at z<1, and find a rise in the SFR density \propto(1+z)^{3.4}, which we attribute to significant L* evolution. Our H-alpha SFR density of 10^{-1.00\pm0.18} M_sun yr^{-1} Mpc^{-3} is consistent with UV and [O II] measurements at z~1. We discuss how these results compare to other H-alpha surveys at z~0.8, and find that the different methods used to determine survey completeness can lead to inconsistent results. This suggests that future surveys probing fainter luminosities are needed, and more rigorous methods of estimating the completeness should be adopted as standard procedure.Comment: 19 pages (emulate-ApJ format), 16 figures, 5 tables, published in ApJ. Modified to match ApJ versio

    A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: Implications for H0H_0

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    Strong gravitational lensing provides an independent measurement of the Hubble parameter (H0H_0). One remaining systematic is a bias from the additional mass due to a galaxy group at the lens redshift or along the sightline. We quantify this bias for more than 20 strong lenses that have well-sampled sightline mass distributions, focusing on the convergence κ\kappa and shear γ\gamma. In 23% of these fields, a lens group contributes a \ge1% convergence bias; in 57%, there is a similarly significant line-of-sight group. For the nine time delay lens systems, H0H_0 is overestimated by 112+3^{+3}_{-2}% on average when groups are ignored. In 67% of fields with total κ\kappa \ge 0.01, line-of-sight groups contribute 2×\gtrsim 2\times more convergence than do lens groups, indicating that the lens group is not the only important mass. Lens environment affects the ratio of four (quad) to two (double) image systems; all seven quads have lens groups while only three of 10 doubles do, and the highest convergences due to lens groups are in quads. We calibrate the γ\gamma-κ\kappa relation: log(κtot)=(1.94±0.34)log(γtot)+(1.31±0.49)\log(\kappa_{\rm{tot}}) = (1.94 \pm 0.34) \log(\gamma_{\rm{tot}}) + (1.31 \pm 0.49) with a rms scatter of 0.34 dex. Shear, which, unlike convergence, can be measured directly from lensed images, can be a poor predictor of κ\kappa; for 19% of our fields, κ\kappa is 2γ\gtrsim 2\gamma. Thus, accurate cosmology using strong gravitational lenses requires precise measurement and correction for all significant structures in each lens field.Comment: 34 pages, 11 figures, accepted for publication in Ap

    Evidence for non-stellar rest-frame near-IR emission associated with increased star formation in galaxies at z1z \sim 1

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    We explore the presence of non-stellar rest-frame near-IR (25 μm2-5 \ \mu \mathrm{m}) emission in galaxies at z1z \sim 1. Previous studies identified this excess in relatively small samples and suggested that such non-stellar emission, which could be linked to the 3.3 μm3.3 \ \mu \mathrm{m} polycyclic aromatic hydrocarbons feature or hot dust emission, is associated with an increased star formation rate (SFR). In this Letter, we confirm and quantify the presence of an IR excess in a significant fraction of galaxies in the 3D-HST GOODS catalogs. By constructing a matched sample of galaxies with and without strong non-stellar near-IR emission, we find that galaxies with such emission are predominantly star-forming galaxies. Moreover, star-forming galaxies with an excess show increased mid- and far-IR and Hα\alpha emission compared to other star-forming galaxies without. While galaxies with a near-IR excess show a larger fraction of individually detected X-ray active galactic nuclei (AGNs), an X-ray stacking analysis, together with the IR-colors and Hα\alpha profiles, shows that AGNs are unlikely to be the dominant source of the excess in the majority of galaxies. Our results suggest that non-stellar near-IR emission is linked to increased SFRs and is ubiquitous among star-forming galaxies. As such, the near-IR emission might be a powerful tool to measure SFRs in the era of the James Webb Space Telescope.Comment: 6 pages, 5 figures, accepted for publication in ApJ

    The Number Density Evolution of Extreme Emission Line Galaxies in 3D-HST: Results from a Novel Automated Line Search Technique for Slitless Spectroscopy

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    The multiplexing capability of slitless spectroscopy is a powerful asset in creating large spectroscopic datasets, but issues such as spectral confusion make the interpretation of the data challenging. Here we present a new method to search for emission lines in the slitless spectroscopic data from the 3D-HST survey utilizing the Wide-Field Camera 3 on board the Hubble Space Telescope. Using a novel statistical technique, we can detect compact (extended) emission lines at 90% completeness down to fluxes of 1.5 (3.0) times 10^{-17} erg/s/cm^2, close to the noise level of the grism exposures, for objects detected in the deep ancillary photometric data. Unlike previous methods, the Bayesian nature allows for probabilistic line identifications, namely redshift estimates, based on secondary emission line detections and/or photometric redshift priors. As a first application, we measure the comoving number density of Extreme Emission Line Galaxies (restframe [O III] 5007 equivalent widths in excess of 500 Angstroms). We find that these galaxies are nearly 10 times more common above z~1.5 than at z<0.5. With upcoming large grism surveys such as Euclid and WFIRST as well as grisms featuring prominently on the NIRISS and NIRCam instruments on James Webb Space Telescope, methods like the one presented here will be crucial for constructing emission line redshift catalogs in an automated and well-understood manner.Comment: 16 pages, 14 Figures; Accepted to Ap
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