3,795 research outputs found

    Integral field optical spectroscopy of a representative sample of ULIRGs: II. Two-dimensional kpc-scale extinction structure

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    We investigate the two-dimensional kpc-scale structure of the extinction in a representative sample of local ULIRGs using the Halpha/Hbeta line ratio.We use optical integral field spectroscopy obtained with the INTEGRAL instrument at the William Herschel Telescope. Complementary optical and near-IR high angular resolution HST images have also been used. The extinction exhibits a very complex and patchy structure in ULIRGs on kpc scales, from basically transparent regions to others deeply embedded in dust (Av~0.0 to Av~8.0 mag). Nuclear extinction covers a broad range in Av from 0.6 to 6 mag, 69% of the nuclei having Av>2.0 mag. Extinction in the external regions is substantially lower than in the nuclei with 64% of the ULIRGs in the sample having median Av of less than 2 mag for the entire galaxy. While post-coalescence nuclei tend to cluster around Av values of 2 to 3 mag, pre-coalescence nuclei appear more homogeneously distributed over the entire 0.4 mag <Av< 7.7 mag range. For the average extinction (Av~2.0 derived for the ULIRGs of the sample, the ratio of the de-reddened to observed SFR values is 6. The extinction-corrected, Halpha-based SFR ranges from 10 to 300 Msun/yr. For only 28% of the cases the de-reddened SFR is <20 Msun/yr, whereas for the observed SFR this percentage increases to 72%. The IR-based SFR is always higher than the optical-based one, with differences ranging from about 2 to up to 30. The nuclear observed SFR has an average contribution to the total one of 16% for the entire sample. Once corrected for extinction, the average value becomes 31%. Because of mostly extinction effects, the optical (I-band) half-light radius in the sample galaxies is on average a factor 2.3 larger than the corresponding near-IR (H-band) value.Comment: To appear in A&

    Aqu\ued hay gato encerrado

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    Attivit\ue0 didattica di fraseologia spagnola in soporto digitale (casa editrice SM, Madrid) http://www.sm-ele.com/ArchivosColegios/NuevoELEAdmin/Archivos/MasClaroQueElAgua/PROYECTO%20GATO.pd

    "Historia de las palabras"

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    En el art\uedculo se describe una propuesta did\ue1ctica para el aprendizaje de l\ue9xico en ELE basada en una perspectiva etnoling\ufc\uedstica y antropol\uf3gic

    VHE gamma-ray observations of the young synchrotron-dominated SNRs G1.9+0.3 and G330.2+1.0 with H.E.S.S

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    Supernova remnants (SNRs) are widely considered to be accelerators of cosmic rays (CR). They are also expected to produce very-high-energy (VHE; E>100E > 100 GeV) gamma rays through interactions of high-energy particles with the surrounding medium and photon fields. They are, therefore, promising targets for observations with ground-based imaging atmospheric Cherenkov telescopes like the H.E.S.S. telescope array. VHE gamma-ray emission has already been discovered from a number of SNRs, establishing them as a prominent source class in the VHE domain. Of particular interest are the handful of SNRs whose X-ray spectra are dominated by non-thermal synchrotron emission, such as the VHE gamma-ray emitters RX J0852.0-4622 (Vela Jr.) and RX J1713-3946. The shell-type SNRs G1.9+0.3 and G330.2+1.0 also belong to this subclass and are further notable for their young ages (1\leq 1 kyr), especially G1.9+0.3, which was recently determined to be the youngest SNR in the Galaxy (100\sim100 yr). These unique characteristics motivated investigations with H.E.S.S. to search for VHE gamma rays. The results of the H.E.S.S. observations and analyses are presented, along with implications for potential particle acceleration scenarios.Comment: ICRC 2011 proceedings, 4 pages, 2 figures, 3 table

    Wine gums

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    CIAL/CSIC: "La salud va a marcar el futuro de la alimentación con soluciones adaptadas a las necesidades del consumidor"

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    Alimentación, salud y bienestar marcarán las tendencias del sector a corto, medio y largo plazo. También es clave la implantación de nuevos proyectos de innovación que puedan derivar en productos de nutrición personalizada.Peer Reviewe

    Integral field optical spectroscopy of a representative sample of ULIRGs: I. The Data

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    We present a project aimed at studying the structure, dust distribution, ionization state, and kinematics of a representative sample of 22 ULIRGs. The galaxies in the sample undergo different merger phases (they are evenly divided between pre- and post-coalescence systems) and ionization stages (27% HII, 32% LINER, 18% Seyfert, and 23% mixed classifications) over a wide infrared luminosity range (11.8<Lir/Lsun<12.6), which also includes some galaxies of low luminosity. The main aims of this paper are to present the sample and discuss the structure of the stellar and ionized gas components. Our results imply that evolution caused by a merger is occurring in the ionized gas structure of ULIRGs. The present study relies on the use of integral field optical spectroscopy data obtained with the INTEGRAL instrument at the 4.2 m William Herschel Telescope.Comment: To appear in A&A. Paper with higher quality images can be found at http://hera.ph1.uni-koeln.de/ftpspace/maca/Catalog

    Diagenetic paths in a low subsident Triassic Basin: NW zone of Iberian Range Spain.

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    Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu
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