27 research outputs found

    Non-Critical String Duals of N=1 Quiver Theories

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    We construct N=1 non-critical strings in four dimensions dual to strongly coupled N=1 quiver gauge theories in the Coulomb phase, generalizing the string duals of Argyres-Douglas points in N=2 gauge theories. They are the first examples of superstrings vacua with an exact worldsheet description dual to chiral N=1 theories. We identify the dual of the non-critical superstring using a brane setup describing the field theory in the classical limit. We analyze the spectrum of chiral operators in the strongly coupled regime and show how worldsheet instanton effects give non-perturbative information about the gauge theory. We also consider aspects of D-branes relevant for the holographic duality.Comment: JHEP style; 40 pages, 3 figures; v2: minor corrections, refs added, version to appear in JHE

    An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field-South: detection of [C II] at z = 4.4

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    We present Atacama Large Millimeter Array (ALMA) 870-μm (345-GHz) observations of two submillimetre galaxies (SMGs) drawn from an ALMA study of the 126 submillimetre sources from the LABOCA Extended Chandra Deep Field-South Survey (LESS). The ALMA data identify the counterparts to these previously unidentified submillimetre sources and serendipitously detect bright emission lines in their spectra which we show are most likely to be [CII] 157.74 μm emission yielding redshifts of z = 4.42 and 4.44. This blind detection rate within the 7.5-GHz bandpass of ALMA is consistent with the previously derived photometric redshift distribution of SMGs and suggests a modest, but not dominant (≲25 per cent), tail of 870-μm selected SMGs at z ≳ 4. We find that the ratio of L[C II]/LFIR in these SMGs is much higher than seen for similarly far-infrared-luminous galaxies at z ˜ 0, which is attributed to the more extended gas reservoirs in these high-redshift ultraluminous infrared galaxies (ULIRGs). Indeed, in one system we show that the [C II] emission shows hints of extended emission on ≳ 3 kpc scales. Finally, we use the volume probed by our ALMA survey to show that the bright end of the [C II] luminosity function evolves strongly between z = 0 and ˜4.4, reflecting the increased interstellar medium cooling in galaxies as a result of their higher star formation rates. These observations demonstrate that even with short integrations, ALMA is able to detect the dominant fine-structure cooling lines from high-redshift ULIRGs, measure their energetics and spatially resolved properties and trace their evolution with redshift

    SPACE: the spectroscopic all-sky cosmic explorer

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    We describe the scientific motivations, the mission concept and the instrumentation of SPACE, a class-M mission proposed for concept study at the first call of the ESA Cosmic-Vision 2015–2025 planning cycle. SPACE aims to produce the largest three-dimensional evolutionary map of the Universe over the past 10 billion years by taking near-IR spectra and measuring redshifts for more than half a billion galaxies at 0 < z < 2 down to AB ∼ 23 over 3π sr of the sky. In addition, SPACE will also target a smaller sky field, performing a deep spectroscopic survey of millions of galaxies to AB ∼ 26 and at 2 < z < 10+. These goals are unreachable with ground-based observations due to the ≈500 times higher sky background (see e.g. Aldering, LBNL report number LBNL-51157, 2001). To achieve the main science objectives, SPACE will use a 1.5 m diameter Ritchey- Chretien telescope equipped with a set of arrays of Digital Micro-mirror Devices covering a total field of view of 0.4 deg2, and will perform large-multiplexing multi-object spectroscopy (e.g. ≈6000 targets per pointing) at a spectral resolution of R∼400 as well as diffraction-limited imaging with continuous coverage from 0.8 to 1.8 μm. Owing to the depth, redshift range, volume coverage and quality of its spectra, SPACE will reveal with unique sensitivity most of the fundamental cosmological signatures, including the power spectrum of density fluctuations and its turnover. SPACE will also place high accuracy constraints on the dark energy equation of state parameter and its evolution by measuring the baryonic acoustic oscillations imprinted when matter and radiation decoupled, the distanceluminosity relation of cosmological supernovae, the evolution of the cosmic expansion rate, the growth rate of cosmic large-scale structure, and high-z galaxy clusters. The datasets from the SPACE mission will represent a long lasting legacy for the whole astronomical community whose data will be mined for many years to come

    Inequality in Brazilian women’s access to medicines for chronic diseases

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    O objetivo deste trabalho foi analisar a prevalência de acesso a medicamentos para tratamento de doenças crônicas e a existência de desigualdades socioeconômicas no acesso. Os dados são da Pesquisa Nacional de Demografia e Saúde e da Mulher e da Criança de 2006, com uma amostra de 15.575 mulheres (15 a 49 anos). Dessas, 7.717 tiveram diagnóstico de doença crônica com necessidade de obtenção de medicamento e foram consideradas elegíveis para o estudo. O desfecho foi construído com base no diagnóstico de doença crônica e na necessidade de obtenção de medicamento para o tratamento. A análise ajustada foi conduzida usando-se a regressão de Poisson. Os grupos que apresentaram maior prevalência de acesso foram os domiciliados na zona rural, com uma ou duas doenças crônicas e com nível socioeconômico mais elevado. A prevalência de acesso encontrada foi alta, no entanto, as análises demonstram que existe desigualdade socioeconômica no acesso a medicamentos a favor dos mais ricos, identificando como grupo mais vulnerável aquele dos indivíduos mais pobres e com maior número de doenças crônicas

    Trajectories of Sugar Consumption and Dental Caries in Early Childhood

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    This study verifies the association between the trajectory of sugar consumption and dental caries in the 2015 Pelotas Birth Cohort in Pelotas, Brazil. It was conducted with data from the follow-ups at 3, 12, 24, and 48 mo from the 2015 Birth Cohort, which included 4,275 children born alive in hospitals in Pelotas. Data collection included standardized questionnaires for first caregivers applied by trained interviewers at all follow-ups. Exposure was the trajectory of sugar consumption from 3 to 48 mo (always low, always intermediate, increasing, and always high), obtained by group-based trajectory modeling. The outcome of this study was dental caries, obtained through clinical examination performed by calibrated dentists at 48 mo of age. Socioeconomic conditions and oral health instruction from a health professional during the first 4 y of life were included in the analysis as potential confounders. Prevalence ratios and their 95% confidence intervals were provided from generalized estimating equations with a log-Poisson with robust variance specification. In total, 3,654 (91.1%) children participated in the survey at 48 mo, and 2,806 children had complete data for the analyzes performed. Of these, 1,012 (36.1%; 95% confidence interval [CI], 34.3-37.8) experienced caries, and 723 (25.8%; 95% CI, 24.2-27.4) had cavitated caries. Regarding cavitated caries, the prevalence was 1.48 times higher in the group with increasing sugar consumption than children with always low consumption. There is an association between the trajectory of sugar consumption and dental caries at 48 mo. Children with increasing and always high sugar consumption have the highest prevalence of caries

    An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South : high-resolution 870 μm source counts

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    We report the first counts of faint submillimetre galaxies (SMGs) in the 870-μm band derived from arcsecond-resolution observations with the Atacama Large Millimeter Array (ALMA). We have used ALMA to map a sample of 122 870-μm-selected submillimetre sources drawn from the 0.5°×0.5° the Large Apex BOlometer CAmera (LABOCA) Extended Chandra Deep Field South submillimetre survey (LESS). These ALMA maps have an average depth of σ870 μm ˜ 0.4 mJy, some approximately three times deeper than the original LABOCA survey and critically the angular resolution is more than an order of magnitude higher, FWHM of ˜1.5 arcsec compared to ˜19 arcsec for the LABOCA discovery map. This combination of sensitivity and resolution allows us to precisely pinpoint the SMGs contributing to the submillimetre sources from the LABOCA map, free from the effects of confusion. We show that our ALMA-derived SMG counts broadly agree with the submillimetre source counts from previous, lower resolution single-dish surveys, demonstrating that the bulk of the submillimetre sources are not caused by blending of unresolved SMGs. The difficulty which well-constrained theoretical models have in reproducing the high surface densities of SMGs, thus remains. However, our observations do show that all of the very brightest sources in the LESS sample, S870 μm ≳ 12 mJy, comprise emission from multiple, fainter SMGs, each with 870-μm fluxes of ≲9 mJy. This implies a natural limit to the star formation rate in SMGs of ≲103 M⊙ yr-1, which in turn suggests that the space densities of z > 1 galaxies with gas masses in excess of ˜5 × 1010 M⊙ is <10-5 Mpc-3. We also discuss the influence of this blending on the identification and characterization of the SMG counterparts to these bright submillimetre sources and suggest that it may be responsible for previous claims that they lie at higher redshifts than fainter SMGs

    Kiloparsec-scale Dust Disks in High-redshift Luminous Submillimeter Galaxies

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    We present high-resolution (0farcs16) 870 μm Atacama Large Millimeter/submillimeter Array (ALMA) imaging of 16 luminous (LIR∼4×1012 L⊙{L}_{\mathrm{IR}}\sim 4\times {10}^{12}\,{L}_{\odot }) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. This dust imaging traces the dust-obscured star formation in these z∼2.5z\sim 2.5 galaxies on ~1.3 kpc scales. The emission has a median effective radius of R e = 0farcs24 ± 0farcs02, corresponding to a typical physical size of Re={R}_{e}= 1.8 ± 0.2 kpc. We derive a median Sérsic index of n = 0.9 ± 0.2, implying that the dust emission is remarkably disk-like at the current resolution and sensitivity. We use different weighting schemes with the visibilities to search for clumps on 0farcs12 (~1.0 kpc) scales, but we find no significant evidence for clumping in the majority of cases. Indeed, we demonstrate using simulations that the observed morphologies are generally consistent with smooth exponential disks, suggesting that caution should be exercised when identifying candidate clumps in even moderate signal-to-noise ratio interferometric data. We compare our maps to comparable-resolution Hubble Space Telescope H160{H}_{160}-band images, finding that the stellar morphologies appear significantly more extended and disturbed, and suggesting that major mergers may be responsible for driving the formation of the compact dust disks we observe. The stark contrast between the obscured and unobscured morphologies may also have implications for SED fitting routines that assume the dust is co-located with the optical/near-IR continuum emission. Finally, we discuss the potential of the current bursts of star formation to transform the observed galaxy sizes and light profiles, showing that the z∼0z\sim 0 descendants of these SMGs are expected to have stellar masses, effective radii, and gas surface densities consistent with the most compact massive (M∗ ∼{M}_{* }\,\sim 1–2 × 1011 M⊙{M}_{\odot }) early-type galaxies observed locally
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