2,651 research outputs found

    Turbulence and the formation of filaments, loops and shock fronts in NGC 1275 in the Perseus Galaxy Cluster

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    NGC1275, the central galaxy in the Perseus cluster, is the host of gigantic hot bipolar bubbles inflated by AGN jets observed in the radio as Perseus A. It presents a spectacular HőĪH{\alpha}-emitting nebulosity surrounding NGC1275, with loops and filaments of gas extending to over 50 kpc. The origin of the filaments is still unknown, but probably correlates with the mechanism responsible for the giant buoyant bubbles. We present 2.5 and 3-dimensional MHD simulations of the central region of the cluster in which turbulent energy, possibly triggered by star formation and supernovae (SNe) explosions is introduced. The simulations reveal that the turbulence injected by massive stars could be responsible for the nearly isotropic distribution of filaments and loops that drag magnetic fields upward as indicated by recent observations. Weak shell-like shock fronts propagating into the ICM with velocities of 100-500 km/s are found, also resembling the observations. The isotropic outflow momentum of the turbulence slows the infall of the intracluster medium, thus limiting further starburst activity in NGC1275. As the turbulence is subsonic over most of the simulated volume, the turbulent kinetic energy is not efficiently converted into heat and additional heating is required to suppress the cooling flow at the core of the cluster. Simulations combining the MHD turbulence with the AGN outflow can reproduce the temperature radial profile observed around NGC1275. While the AGN mechanism is the main heating source, the supernovae are crucial to isotropize the energy distribution.Comment: accepted by ApJ Letter

    Investigadores de Panam√° con perfil p√ļblico en Google Scholar 2021

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    Las instituciones de educación superior en Panamá carecen de un instrumento que permita conocer la visibilidad de sus investigadores y el impacto de sus publicaciones. Este enlace es un espacio creado para el libro de perfiles de Panamá 2021 que será publicado en Diciembre 2021. El presente documento agrupa los indicadores bibliométricos por organismo en orden decreciente como una manera de organizarlos para una lectura comprensible, y no se considera una análisis, interpretación o comparación de los investigadores, organismos o áreas del conocimiento. Este trabajo es un estudio de perfiles de investigadores de Panamá en Google Scholar(GS) que tiene el objetivo identificar la visibilidad e impacto de los investigadores y publicaciones utilizando indicadores Bibliométricos, la información expuesta en este documento es una herramienta que muestre el nivel de visibilidad de los investigadores y el impacto generado de las citaciones proveniente de sus publicaciones.Las instituciones de educación superior en Panamá carecen de un instrumento que permita conocer la visibilidad de sus investigadores y el impacto de sus publicaciones. El presente documento agrupa los indicadores bibliométricos por organismo en orden decreciente como una manera de organizarlos para una lectura comprensible, y no se considera una análisis, interpretación o comparación de los investigadores, organismos o áreas del conocimiento. Este trabajo es un estudio de perfiles de investigadores de Panamá en Google Scholar(GS) que tiene el objetivo identificar la visibilidad e impacto de los investigadores y publicaciones utilizando indicadores Bibliométricos, la información expuesta en este documento es una herramienta que muestre el nivel de visibilidad de los investigadores y el impacto generado de las citaciones proveniente de sus publicaciones. Este enlace es uspacio creado para el libro de perfiles de Panamá 2021 que será publicado en Diciembre 2021

    Investigadores de Panam√° con perfil p√ļblico en Google Scholar (Marzo 2020)

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    Perfiles institucionales con o sin afiliaci√≥n a Google Scholar, se seleccionaron todos los perfiles p√ļblicos con o sin citaciones, pero con al menos una publicaci√≥n. Objetivo: Dar visibilidad a los perfiles p√ļblicos en Google Scholar de investigadores miembros de instituciones y organizaciones en Panam√° para promover el uso y creaci√≥n de su perfil en esta plataforma. Para ello damos a conocer a la comunidad cient√≠fica y acad√©mica el listado de investigadores que han creado su perfil, mostrando los indicadores del impacto de las publicaciones por citaci√≥n, hindex y los enlaces a cada perfil P√ļblico. Los perfiles se agrupan por instituci√≥n y si es miembro del SNI tambi√©n se clasifica por √°rea tem√°tica y especialidad.Perfiles institucionales con o sin afiliaci√≥n a Google Scholar, se seleccionaron todos los perfiles p√ļblicos con o sin citaciones, pero con al menos una publicaci√≥n. Objetivo: Dar visibilidad a los perfiles p√ļblicos en Google Scholar de investigadores miembros de instituciones y organizaciones en Panam√° para promover el uso y creaci√≥n de su perfil en esta plataforma. Para ello damos a conocer a la comunidad cient√≠fica y acad√©mica el listado de investigadores que han creado su perfil, mostrando los indicadores del impacto de las publicaciones por citaci√≥n, hindex y los enlaces a cada perfil P√ļblico. Los perfiles se agrupan por instituci√≥n y si es miembro del SNI tambi√©n se clasifica por √°rea tem√°tica y especialidad

    A global database for metacommunity ecology, integrating species, traits, environment and space

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    The use of functional information in the form of species traits plays an important role in explaining biodiversity patterns and responses to environmental changes. Although relationships between species composition, their traits, and the environment have been extensively studied on a case-by-case basis, results are variable, and it remains unclear how generalizable these relationships are across ecosystems, taxa and spatial scales. To address this gap, we collated 80 datasets from trait-based studies into a global database for metaCommunity Ecology: Species, Traits, Environment and Space; ‚ÄúCESTES‚ÄĚ. Each dataset includes four matrices: species community abundances or presences/absences across multiple sites, species trait information, environmental variables and spatial coordinates of the sampling sites. The CESTES database is a live database: it will be maintained and expanded in the future as new datasets become available. By its harmonized structure, and the diversity of ecosystem types, taxonomic groups, and spatial scales it covers, the CESTES database provides an important opportunity for synthetic trait-based research in community ecology

    Abnormal visuomotor processing in schizophrenia

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    Subtle disturbances of visual and motor function are known features of schizophrenia and can greatly impact quality of life; however, few studies investigate these abnormalities using simple visuomotor stimuli. In healthy people, electrophysiological data show that beta band oscillations in sensorimotor cortex decrease during movement execution (event-related beta desynchronisation (ERBD)), then increase above baseline for a short time after the movement (post movement beta rebound (PMBR)); while in visual cortex, gamma oscillations are increased throughout stimulus presentation. In this study, we used a selfpaced visuomotor paradigm and magnetoencephalography (MEG) to contrast these responses in patients with schizophrenia and control volunteers. We found significant reductions in the peak-to-peak change in amplitude from ERBD to PMBR in schizophrenia compared with controls. This effect was strongest in patients who made fewer movements, whereas beta was not modulated by movement in controls. There was no significant difference in the amplitude of visual gamma between patients and controls. These data demonstrate that clear abnormalities in basic sensorimotor processing in schizophrenia can be observed using a very simple MEG paradig

    First-Hand Experience and Second-Hand Information: Changing Trust across Three Levels of Government

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    Little is known about how different sources of information drive citizen trust in government. To address that gap this article compares disaster evacuees to observers, noting how trust differs as attention to media coverage increases. First-hand experience supplies information to update trust through biological and personal processes and performance assessments, while secondary sources provide information about other people's experiences, filtered through lenses that take an active role in crafting information. These two types of information have varying effects depending on the level of government being trusted. Using surveys administered a year after Hurricane Katrina, I find that Katrina evacuees have the highest trust in federal government, until they start paying attention to media coverage, and that attention to coverage has the most dramatic effect on these evacuees compared to all other groups. I also find that increasing attention to second-hand information corresponds with higher trust in local officials, and that this effect decreases as the level of government increases. It appears media coverage creates a comparison in the mind of hurricane evacuees, causing them to update their performance assessments based on comparing their own experience to that which they observe, thereby updating their political trust

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+‚Üíőľ+őĹW^+ \rightarrow \mu^+\nu and W‚ąí‚Üíőľ‚ąíőĹW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC