47 research outputs found

    What a difference a term makes:the effect of educational attainment on marital outcomes in the UK

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    Abstract In the past, students in England and Wales born within the first 5 monthsof the academic year could leave school one term earlier than those born later inthe year. Focusing on women, those who were required to stay on an extra termmore frequently hold some academic qualification. Using having been required tostay on as an exogenous factor affecting academic attainment, we find that holding alow-level academic qualification has no effect on the probability of being currentlymarried for women aged 25 or above, but increases the probability of the husbandholding some academic qualification and being economically active.33 Halama

    The Sextet Arcs: a Strongly Lensed Lyman Break Galaxy in the ACS Spectroscopic Galaxy Survey towards Abell 1689

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    We present results of the HST Advanced Camera for Surveys spectroscopic ground-based redshift survey in the field of A1689. We measure 98 redshifts, increasing the number of spectroscopically confirmed objects by sixfold. We present two spectra from this catalog of the Sextet Arcs, images which arise from a strongly-lensed Lyman Break Galaxy (LBG) at a redshift of z=3.038. Gravitational lensing by the cluster magnifies its flux by a factor of ~16 and produces six separate images with a total r-band magnitude of r_625=21.7. The two spectra, each of which represents emission from different regions of the LBG, show H I and interstellar metal absorption lines at the systemic redshift. Significant variations are seen in Ly-alpha profile across a single galaxy, ranging from strong absorption to a combination of emission plus absorption. A spectrum of a third image close to the brightest arc shows Ly-alpha emission at the same redshift as the LBG, arising from either another spatially distinct region of the galaxy, or from a companion galaxy close to the LBG. Taken as a group, the Ly-alpha equivalent width in these three spectra decreases with increasing equivalent width of the strongest interstellar absorption lines. We discuss how these variations can be used to understand the physical conditions in the LBG. Intrinsically, this LBG is faint, ~0.1L*, and forming stars at a modest rate, ~4 solar masses per year. We also detect absorption line systems toward the Sextet Arcs at z=2.873 and z=2.534. The latter system is seen across two of our spectra.Comment: Accepted for publication in Ap

    The Highest Resolution Mass Map of Galaxy Cluster Substructure To Date Without Assuming Light Traces Mass: LensPerfect Analysis of Abell 1689

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    We present a strong lensing mass model of Abell 1689 which resolves substructures ~25 kpc across (including about ten individual galaxy subhalos) within the central ~400 kpc diameter. We achieve this resolution by perfectly reproducing the observed (strongly lensed) input positions of 168 multiple images of 55 knots residing within 135 images of 42 galaxies. Our model makes no assumptions about light tracing mass, yet we reproduce the brightest visible structures with some slight deviations. A1689 remains one of the strongest known lenses on the sky, with an Einstein radius of RE = 47.0" +/- 1.2" (143 +3/-4 kpc) for a lensed source at zs = 2. We find a single NFW or Sersic prole yields a good fit simultaneously (with only slight tension) to both our strong lensing (SL) mass model and published weak lensing (WL) measurements at larger radius (out to the virial radius). According to this NFW fit, A1689 has a mass of Mvir = 2.0 +0.5/-0.3 x 10^15 Msun / h70 (M200 = 1.8 +0.4/-0.3 x 10^15 Msun / h70) within the virial radius rvir = 3.0 +/- 0.2 Mpc / h70 (r200 = 2.4 +0.1/-0.2 Mpc / h70), and a central concentration cvir = 11.5 +1.5/-1.4 (c200 = 9.2 +/- 1.2). Our SL model prefers slightly higher concentrations than previous SL models, bringing our SL+WL constraints in line with other recent derivations. Our results support those of previous studies which find A1689 has either an anomalously large concentration or significant extra mass along the line of sight (perhaps in part due to triaxiality). If clusters are generally found to have higher concentrations than realized in simulations, this could indicate they formed earlier, perhaps as a result of early dark energy.Comment: 27 pages, 17 figures, submitted to ApJ. See http://www.its.caltech.edu/~coe/LPA1689/ for complete set of color multiple images (observed and delensed) and more. Comments welcome at http://scirate.com/who.php?id=1005.xxxx&what=comments (insert arXiv number at xxxx; free & easy registration

    Strong Lensing Analysis of A1689 from Deep Advanced Camera Images

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    We analyse deep multi-colour Advanced Camera images of the largest known gravitational lens, A1689. Radial and tangential arcs delineate the critical curves in unprecedented detail and many small counter-images are found near the center of mass. We construct a flexible light deflection field to predict the appearance and positions of counter-images. The model is refined as new counter-images are identified and incorporated to improve the model, yielding a total of 106 images of 30 multiply lensed background galaxies, spanning a wide redshift range, 1.0<<z<<5.5. The resulting mass map is more circular in projection than the clumpy distribution of cluster galaxies and the light is more concentrated than the mass within r<50kpc/hr<50kpc/h. The projected mass profile flattens steadily towards the center with a shallow mean slope of dlogΣ/dlogr0.55±0.1d\log\Sigma/d\log r \simeq -0.55\pm0.1, over the observed range, r<250kpc/h<250kpc/h, matching well an NFW profile, but with a relatively high concentration, Cvir=8.21.8+2.1C_{vir}=8.2^{+2.1}_{-1.8}. A softened isothermal profile (rcore=20±2r_{core}=20\pm2\arcs) is not conclusively excluded, illustrating that lensing constrains only projected quantities. Regarding cosmology, we clearly detect the purely geometric increase of bend-angles with redshift. The dependence on the cosmological parameters is weak due to the proximity of A1689, z=0.18z=0.18, constraining the locus, ΩM+ΩΛ1.2\Omega_M+\Omega_{\Lambda} \leq 1.2. This consistency with standard cosmology provides independent support for our model, because the redshift information is not required to derive an accurate mass map. Similarly, the relative fluxes of the multiple images are reproduced well by our best fitting lens model.Comment: Accepted by ApJ. For high quality figures see http://wise-obs.tau.ac.il/~kerens/A168

    Four-year follow-up of weight loss maintenance using electronic medical record data: The PROPEL trial

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    Rationale: Short-term weight loss is possible in a variety of settings. However, long-term, free-living weight loss maintenance following structured weight loss interventions remains elusive. Objective: The purpose was to study body weight trajectories over 2 years of intensive lifestyle intervention (ILI) and up to 4 years of follow-up versus usual care (UC). Methods: Data were obtained from electronic medical records (EMRs) from participating clinics. Baseline (Day 0) was established as the EMR data point closest but prior to the baseline date of the trial. The sample included 111 ILI and 196 UC patients. The primary statistical analysis focused on differentiating weight loss trajectories between ILI and UC. Results: The ILI group experienced significantly greater weight loss compared with the UC group from Day 100 to Day 700, beyond which there were no significant differences. Intensive lifestyle intervention patients who maintained ≥5% and ≥10% weight loss at 24 months demonstrated significantly greater weight loss (p \u3c 0.001) across the active intervention and follow-up. Conclusions: Following 24 months of active intervention, patients with ILI regained weight toward their baseline to the point where ILI versus UC differences were no longer statistically or clinically significant. However, patients in the ILI who experienced ≥5% or ≥10% weight loss at the cessation of the active intervention maintained greater weight loss at the end of the follow-up phase. Clinical Trial Registration: ClinicalTrials.gov: NCT02561221

    Geology of the Cenozoic Indus Basin sedimentary rocks : paleoenvironmental interpretation of sedimentation from the western Himalaya during the early phases of India-Eurasia collision.

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    This study reassesses the stratigraphy, sedimentology, and provenance of the Indus Basin sedimentary rocks, deposited within the Indus Tsangpo Suture Zone (ITSZ) during the early phases of India‐Eurasia collision. Using field observations, biostratigraphy, and petrographic and isotopic analyses we create a paleodepositional reconstruction within the paleotectonic setting of the early phases of India‐Eurasia collision. We then re‐examine existing constraints to the timing of India‐Eurasia collision previously interpreted from the earliest occurrence of mixed Indian‐ and Eurasian‐derived detritus in the succession. From mid‐Cretaceous to early Paleocene times the Jurutze and Sumda Formations were deposited within an arc‐bounded marine basin between the Dras and Kohistan‐Ladakh Island arcs. The <51 Ma aged deltaic Chogdo Formation then filled the basin until deposition of the 50.8–49.4 Ma aged Nummulitic Limestone during a marine incursion, before continental facies developed in an evolving intermountain basin with the deposition of the Paleogene Indus Group. Within these systems, sediment was sourced from the Eurasian margin to the north and was transported southward into the suture zone. In this section, we see no unequivocal evidence of Indian Plate input to the sedimentary succession (and thus no evidence of mixed Indian‐Eurasian‐derived detritus indicative of India‐Asia collision) until the upper stratigraphic horizons of the Indus Group, when facies are representative of an axial, northwesterly flowing river system. We suggest that the paleo‐Indus River was initiated within the ITSZ during late Oligocene‐early Miocene times. Sedimentation of the Indus Group continued until the late Miocene
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