The WFCAM Multi-wavelength Variable Star Catalog

Stellar variability in the near-infrared (NIR) remains largely unexplored. The exploitation of public science archives with data-mining methods offers a perspective for the time-domain exploration of the NIR sky. We perform a comprehensive search for stellar variability using the optical-NIR multi-band photometric data in the public Calibration Database of the WFCAM Science Archive (WSA), with the aim of contributing to the general census of variable stars, and to extend the current scarce inventory of accurate NIR light curves for a number of variable star classes. We introduce new variability indices designed for multi-band data with correlated sampling, and apply them for pre-selecting variable star candidates, i.e., light curves that are dominated by correlated variations, from noise-dominated ones. Pre-selection criteria are established by robust numerical tests for evaluating the response of variability indices to colored noise characteristic to the data. We find 275 periodic variable stars and an additional 44 objects with suspected variability with uncertain periods or apparently aperiodic variation. Only 44 of these objects had been previously known, including 11 RR~Lyrae stars in the outskirts of the globular cluster M3 (NGC~5272). We provide a preliminary classification of the new variable stars that have well-measured light curves, but the variability types of a large number of objects remain ambiguous. We classify most of the new variables as contact binary stars, but we also find several pulsating stars, among which 34 are probably new field RR~Lyrae and 3 are likely Cepheids. We also identify 32 highly reddened variable objects close to previously known dark nebulae, suggesting that these are embedded young stellar objects. We publish our results and all light-curve data as the WFCAM Variable Star Catalog.Comment: 21 pages, 11 figure

Recomendações técnicas para criação de cabras leiteiras.

Raças indicadas; Parda Alpina; Toggenburg; Saanen; Anglo-Nubiana;Manejo reprodutivo; Seleção de Reprodutores; Seleção de Matrizes; Puberdade e Maturidade Sexual; Ciclo Estral e Estro; Rufião; Sistema de Acasalamento; Período de Gestação; Cuidados Durante a Gestação; Parto; Manejo das crias; Mamada do Colostro; Tratamento do Umbigo; Identificação; Permanência da Cria com a Mãe; Aleitamento Artificial; Descorna; Desmame e Separação por Sexo; Castração; Alimentação e nutrição; Pastagem Cultivada; Manejo de Utilização de Capineira de Capim Elefante; Irrigação; Formas de Utilização do Capim; Suplementação Alimentar; Banco de Proteína; Leucena (Leucaena leucocephala); Feijão Guandu (Cajanus cajan); Cunhã (Clitoria ternatea L.); Suplementação Mineral; Exigências Nutricionais de Cabras Leiteiras; Manejo sanitário; Endoparasitoses; Helmintoses (verminose gastrintestinal); Eimeriose (coccidiose); Ectoparasitoses; Pediculose (piolho); Miíase (bicheira); Sarnas; Doenças Causadas por Bactérias; Mamite (mastite); Linfadenite caseosa (mal do caroço); Ceratoconjuntivite infecciosa (oftalmia contagiosa); Pododermatite (frieira ou mal do casco); Micoplasmose; Doenças Causadas por Vírus; Ectima contagioso (boqueira); Artrite-encefalite caprina viral (CAEV); Doenças Metabólicas e Carenciais; Urolitíase obstrutiva (cálculo urinário); Toxemia da gestação (acetonemia ou hipoglicemia); Instalações; Aprisco e Chiqueiro; Currais de manejo; Pedilúvio; Cochos para Sal Mineral (Saleiro); Cercas; Área de Isolamento.bitstream/item/35660/1/CIT25.pd

Massive higher spins and holography

We review recent progress towards the understanding of higher spin gauge symmetry breaking in AdS space from a holographic vantage point. According to the AdS/CFT correspondence, N=4 SYM theory at vanishing coupling constant should be dual to a theory in AdS which exhibits higher spin gauge symmetry enhancement. When the SYM coupling is non-zero, all but a handful of HS currents are violated by anomalies, and correspondingly local higher spin symmetry in the bulk gets spontaneously broken. In agreement with previous results and holographic expectations, we find that, barring one notable exception (spin 1 eating spin 0), the Goldstone modes responsible for HS symmetry breaking in AdS have non-vanishing mass even in the limit in which the gauge symmetry is restored. We show that spontaneous breaking a' la Stueckelberg implies that the mass of the relevant spin s'=s-1 Goldstone field is exactly the one predicted by the correspondence.Comment: 8 pages, talk presented by M.B. at the "Fourth Meeting on Constrained Dynamics and Quantum gravity" held in Cala Gonone (Sardinia, Italy), September 12-16, 200

On the spectrum of AdS/CFT beyond supergravity

We test the spectrum of string theory on AdS_5 x S^5 derived in hep-th/0305052 against that of single-trace gauge invariant operators in free N=4 super Yang-Mills theory. Masses of string excitations at critical tension are derived by extrapolating plane-wave frequencies at g_{YM}=0 down to finite J. On the SYM side, we present a systematic description of the spectrum of single-trace operators and its reduction to PSU(2,2|4) superconformal primaries via a refined Eratostenes' supersieve. We perform the comparison of the resulting SYM/string spectra of charges and multiplicities order by order in the conformal dimension \Delta up to \Delta=10 and find perfect agreement. Interestingly, the SYM/string massive spectrum exhibits a hidden symmetry structure larger than expected, with bosonic subgroup SO(10,2) and thirty-two supercharges.Comment: 28 pages, LaTeX2

X-ray Evidence of the Common Envelope Phase of V471 Tauri

Chandra Low Energy Transmission Grating Spectrograph observations of the pre-cataclysmic binary V471 Tau have been used to estimate the C/N abundance ratio of the K dwarf component for the first time. While the white dwarf component dominates the spectrum longward of 50 AA, at shorter wavelengths the observed X-ray emission is entirely due to coronal emission from the K dwarf. The H-like resonance lines of C and N yield an estimate of their logarithmic abundance ratio relative to the Sun of [C/N]=-0.38+/-0.15 - half of the currently accepted solar value. We interpret this result as the first clear observational evidence for the presumed common envelope phase of this system, during which the surface of the K dwarf was contaminated by CN-cycle processed material dredged up into the red giant envelope. We use the measured C/N ratio to deduce that 0.015-0.04 Msun was accreted by the K dwarf while engulfed, and show that this is consistent with a recent tentative detection of 13C in the K dwarf photosphere, and with the measured Li abundance in the scenario where the red giant companion was Li-rich during the common envelope phase.Comment: 6 pages, 2 figures, ApJL accepte

Informações sobre as cultivares de trigo recomendadas para plantio em 1988 no Rio Grande do Sul.

bitstream/item/119410/1/FOL-06007.pd

Higher Derivative BLG: Lagrangian and Supersymmetry Transformations

Working to lowest non-trivial order in fermions, we consider the four-derivative order corrected Lagrangian and supersymmetry transformations of the Euclidean Bagger-Lambert-Gustavsson theory. By demonstrating supersymmetric invariance of the Lagrangian we determine all numerical coefficients in the system. In addition, the supersymmetry algebra is shown to close on the scalar and gauge fields. We also comment on the extension to Lorentzian and other non-Euclidean $\mathcal{N}=8$ 3-algebra theories.Comment: 23 page