197 research outputs found

    Asymmetrical structure of ionization and kinematics in the Seyfert galaxy NGC 5033

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    We present integral field spectroscopy of NGC 5033, a low luminosity Seyfert galaxy. The observations were made with INTEGRAL, a fiber based system operating at the WHT. The intensity map of the Hβ\beta emission line represents a spiral or ring-like pattern of HII regions. On the contrary, the [OIII] intensity map morphology is markedly anisotropic. The strong morphological differences imply that the [OIII] emitters represent highly ionized gas illuminated by the central source. The [OIII] map morphology is compatible with a biconical structure of ionization induced by strong extinction in the galaxy disc that also obscures half of the spheroidal stellar bulge. We identify the spectrum corresponding to the Seyfert 1 nucleus from the presence of Hβ\beta broad emission lines. This spectrum is located in a region where strong extinction is expected but exhibits the bluest spectral energy distribution. The Seyfert 1 nucleus seems to be offcenter with respect to the stellar rotation center. This result has been also found in other Seyfert galaxies and interpreted in terms of a past merger. The offcentering could indicate the presence of nonsymmetric departures in the gravitational potential which could be fueling the active nucleus. The kinematics of the [OIII] emitters show important deviations at a kpc scale with respect to the stellar velocity field and show features related to the asymmetrical morphology of the high ionization region.Comment: 9 pages, accepted for publication in Astronomy and Astrophysics. Figures 1 and 7 are attached as .gif file

    Does perceived restorativeness mediate the effects of perceived biodiversity and perceived naturalness on emotional well-being following group walks in nature?

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    Natural environments are associated with positive health and well-being. However, little is known about the influence of environmental qualities on well-being and the mechanisms underlying this association. This study explored whether perceived restorativeness and it subscales would mediate the effects of perceived biodiversity, perceived naturalness, walk duration and perceived intensity on emotional well-being. Participants (n = 127) of a national walking program in England completed pre- and post-walk questionnaires (n = 1009) for each group walk attended within a 13-week period. Multilevel mediation examined the hypothesised indirect effects. Perceived restorativeness mediated the effects of perceived bird biodiversity, perceived naturalness, and perceived walk intensity on positive affect, happiness and negative affect. The effect of walk duration on happiness was also mediated by perceived restorativeness. Perceived walk intensity had a direct effect on positive affect and happiness. Findings have implications for theory development, future biodiversity-health research and practitioners interested in designing restorative environments

    Axisymmetrical Gas Inflow in the Central Region of NGC 7331

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    New Integral Field Spectroscopy of the central region of NGC 7331 reveals strong Hα\alpha emission in the well-known CO and HI ring of NGC 7331. The [NII]/Hα\alpha ratio indicates that a large scale stellar formation process is taken place at the ring in agreement with previous hypothesis about the exhaustion of gas in the inner to the ring region. The dynamics of stars and gas are not coupled. There is a ring of peculiar velocities in the ionized gas velocity map. These peculiar velocities can be well interpreted by the presence of an axisymmetric inflow of 40 km/s at the inner boundary of the large-scale gaseous ring. We infer an inwards total flux of 1.6 M_{\odot}yr1^{-1}. This value is typical of the accretion rates in hypothetical {\bf large} nuclear black holes. Despite the large differences in the scales of the nucleus and the gas ring of NGC 7331, we suggest that this inwards flux is feeding the nucleus.Comment: 5 pages, 3 figures, to be published in Astronomy and Astrophysic

    Non-circular motion evidences in the circumnuclear region of M100 (NGC 4321)

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    We analyse new integral field spectroscopy of the inner region (central 2.5 kpc) of the spiral galaxy NGC 4321 to study the peculiar kinematics of this region. Fourier analysis of the velocity residuals obtained by subtracting an axisymmetric rotation model from the Hα\rm H\alpha velocity field, indicates that the distortions are {\em global} features generated by an m=2m=2 perturbation of the gravitational potential which can be explained by the nuclear bar. This bar has been previously observed in the near-infrared but not in the optical continuum dominated by star formation. We detect the optical counterpart of this bar in the 2D distribution of the old stellar population (inferred from the equivalent width map of the stellar absorption lines). We apply the Tremaine--Weinberg method to the stellar velocity field to calculate the pattern speed of the inner bar, obtaining a value of Ωb\Omega_b=160±70kms1kpc1\pm70\rm km s^{-1} kpc^{-1} . This value is considerably la rger than the one obtained when a simple bar model is considered. However the uncertainties in the pattern speed determination prevent us to give support to alternative scenarios.Comment: 11 pages, 11 figures, accepted for publication in MNRA

    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

    Integral Field Spectroscopy of the Central Regions of 3C 120: Evidence of a Past Merging Event

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    IFS combined with HST WFPC imaging were used to characterize the central regions of the Seyfert 1 radio galaxy 3C 120. We carried out the analysis of the data, deriving intensity maps of different emission lines and the continua at different wavelengths from the observed spectra. Applying a 2D modeling to the HST images we decoupled the nucleus and the host galaxy, and analyzed the host morphology. The host is a highly distorted bulge dominated galaxy, rich in substructures. We developed a new technique to model the IFS data extending the 2D modeling. Using this technique we separated the Seyfert nucleus and the host galaxy spectra, and derived a residual data cube with spectral and spatial information of the different structures in 3C 120. Three continuum-dominated structures (named A, B, and C) and other three extended emission line regions (EELRs, named E1, E2 and E3) are found in 3C 120 which does not follow the general behavior of a bulge dominated galaxy. We also found shells in the central kpc that may be remnants of a past merging event in this galaxy. The origin of E1 is most probably due to the interaction of the radio-jet of 3C 120 with the intergalactic medium. Structures A, B, and the shell at the southeast of the nucleus seem to correspond to a larger morphological clumpy structure that may be a tidal tail, consequence of the past merging event. We found a bright EELR (E2) in the innermost part of this tidal tail, nearby the nucleus, which shows a high ionization level. The kinematics of the E2 region and its connection to the tidal tail suggest that the tail has channeled gas from the outer regions to the center.Comment: 55 pages, 18 figures and 5 tables Accepted by AP

    PMAS Optical Integral Field Spectroscopy of Luminous Infrared Galaxies. II.-- Spatially resolved stellar populations and excitation conditions

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    The general properties of luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) in the local universe are well known since large samples of these objects have been the subject of numerous spectroscopic works. There are, however, relatively few studies of large samples of LIRGs and ULIRGs using integral field spectroscopy (IFS). We analyze optical (3800-7200A) IFS data taken with the Potsdam Multi-Aperture Spectrophotometer (PMAS) of the central few kiloparsecs of 11 LIRGs. To study the stellar populations we fit the optical stellar continuum and the hydrogen recombination lines of selected regions. We analyze the excitation conditions of the gas using the spatially resolved properties of the brightest optical emission lines. The optical continua of the selected regions are well fitted with a combination of evolved (~0.7-10Gyr) and ionizing (1-20Myr) stellar populations. The latter is more obscured than the evolved population, and has visual extinctions in good agreement with those obtained from the Balmer decrement. Except for NGC 7771, there is no clear evidence for an important contribution to the optical light from an intermediate-aged population (~100-500Myr). Even after correcting for the presence of stellar absorption, a large fraction of spaxels with low observed equivalent widths of Halpha in emission still show enhanced [NII]/Halpha and [SII]/Halpha ratios. These ratios are likely to be produced by a combination of photoionization in HII regions and diffuse emission. These regions of enhanced ratios are generally coincident with low surface brightness HII regions and diffuse emission detected in the Halpha and Pa-alpha images. Using the PMAS line ratios and the NICMOS Pa-alpha photometry of HII regions we find that the fraction of diffuse emission in LIRGs varies from galaxy to galaxy, and it is generally less than 60% as found in other starburst galaxies. (Abridged)Comment: Accepted for publication in A&

    Integral Field Spectroscopy Of The Brightest Knots Of Hh 223 In L723

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    HH 223 is the optical counterpart of a larger scale H2 outflow, driven by the protostellar source VLA 2A, in L723. Its poorly collimated and rather chaotic morphology suggested the Integral Field Spectroscopy (IFS) as an appropriate option to map the emission for deriving the physical conditions and the kinematics. Here we present new results based on the IFS observations made with the INTEGRAL system at the WHT. The brightest knots of HH 223 (\sim16 arcsec, 0.02 pc at a distance of 300 pc) were mapped with a single pointing in the spectral range 6200-7700 A. We obtained the emission-line intensity maps for Halpha, [NII] 6584 A and [SII] 6716, 6731 A, and explored the distribution of the excitation and electron density from [NII]/Halpha, [SII]/Halpha, and [SII] 6716/6731 line-ratio maps. Maps of the radial velocity field were obtained. We analysed the 3D-kinematics by combining the knot radial velocities, derived from IFS data, with the knot proper motions derived from multi-epoch, narrow-band images. The intensity maps built from IFS data reproduced well the morphology found in the narrow-band images. We checked the results obtained from previous long-slit observations with those derived from IFS spectra extracted with a similar spatial sampling. At the positions intersected by the slit, the physical conditions and kinematics derived from IFS are compatible with those derived from long-slit data. In contrast, significant discrepancies were found when the results from long-slit data were compared with the ones derived from IFS spectra extracted at positions shifted a few arcsec from those intersected by the slit. This clearly revealed IFS observations as the best choice to get a reliable picture of the HH emission properties.Comment: 9 pages, 8 figures; Accepted for MNRA

    TP97 299. Experiencia en el uso de válvula aórtica biológica freedom solo en endocarditis

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    IntroducciónLas válvulas aórticas biológicas sin soporte Sorin Freedom Solo (FS) han demostrado una mejoría en el aumento del orificio de área efectivo, así como un mejor perfil en los gradientes transvalvulares, fracción de eyección del ventrículo izquierdo (FEVI) y regresión de la hipertrofia ventricular izquierda. También, se ha comprobado una reducción en los tiempos de isquemia miocárdica y de circulación extracorpórea. Sin embargo no hay mucha información sobre su comportamiento en el contexto de endocarditis valvular.Material y métodosDesde noviembre de 2006 – septiembre 2011, se implantaron 17 prótesis FS en 16 pacientes (50% hombres, 60,2±15 años) por endocarditis bacteriana. Se determinó la cantidad de plaquetas en el día 5 postimplante, así como la fracción de eyección (FE) y los gradientes transvalvulares posquirúrgicos. Seguimiento medio de 22,5±26 meses.ResultadosLa prevalencia de trombocitopenia (< 150.000 plaquetas) y trombocitopenia grave (< 50.000 plaquetas) ha sido de 68,8 y 31,3%, respectivamente. Hubo un total de 4 muertes hospitalarias (25%), 2 intraoperatorias. Gradiente transvalvular medio de 22±18mmHg, FEVI postoperatoria media de 52,4±10,3%. Tres pacientes fueron reintervenidos, 2 por deterioro precoz (16%), 1 por nueva endocarditis (8%).ConclusiónLa prótesis aórtica biológica sin soporte FS muestra un buen perfil hemodinámico, mejorando significati-vamente los gradientes transvalvulares.Nuestra prevalencia de trombocitopenia al quinto día y durabilidad de la válvula se encuentran en valores similares a lo publicado en la literatura.El uso de dicha prótesis en endocarditis aórtica debe considerarse una alternativa eficaz al demostrarse baja tasa de reincidencia de endocarditis
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