| 1. |
- Gonzalez-Alfonso, E., et al.
(författare)
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Molecular Outflows in Local ULIRGs: Energetics from Multitransition OH Analysis
- 2017
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 836:1
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Tidskriftsartikel (refereegranskat)abstract
- We report on the energetics of molecular outflows in 14 local ultraluminous infrared galaxies (ULIRGs) that show unambiguous outflow signatures (P Cygni profiles or high-velocity absorption wings) in the far-infrared lines of OH measured with the Herschel/PACS spectrometer. All sample galaxies are gas-rich mergers at various stages of the merging process. Detection of both ground-state (at 119 and 79 mu m) and one or more radiatively excited (at 65 and 84 mu m) lines allows us to model the nuclear gas (. 300 pc) and the more extended components using spherically symmetric radiative transfer models. Reliable models and the corresponding energetics are found in 12 of the 14 sources. The highest molecular outflow velocities are found in buried sources, in which slower but massive expansion of the nuclear gas is also observed. With the exception of a few outliers, the outflows have momentum fluxes of (2-5) x L-IR/c and mechanical luminosities of (0.1-0.3)% of L-IR. The moderate momentum boosts in these sources (. 3) suggest that the outflows are mostly momentum driven by the combined effects of active galactic nuclei (AGNs) and nuclear starbursts, as a result of radiation pressure, winds, and supernova remnants. In some sources ( similar to 20%), however, powerful (10(10.5- 11) L circle dot) AGN feedback and (partially) energy-conserving phases are required, with momentum boosts in the range of 3-20. These outflows appear to be stochastic, strong AGN feedback events that occur throughout the merging process. In a few sources, the outflow activity in the innermost regions has subsided in the past similar to 1 Myr. While OH traces the molecular outflows at subkiloparsec scales, comparison of the masses traced by OH with those previously inferred from tracers of more extended outflowing gas suggests that most mass is loaded (with loading factors of M/SFR = 1-10) from the central galactic cores (a few. x. 100 pc), qualitatively consistent with an ongoing inside-out quenching of star formation. Outflow depletion timescales are
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| 2. |
- Carpio, Antonio J., et al.
(författare)
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Hunting as a source of alien species : a European review
- 2017
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Ingår i: Biological Invasions. - : Springer Science and Business Media LLC. - 1387-3547 .- 1573-1464. ; 19:4, s. 1197-1211
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Tidskriftsartikel (refereegranskat)abstract
- Hunting activities are responsible for the translocation and restocking of millions of animals throughout Europe, including the introduction of alien species. In a context of the growing use of game translocations and of increasing concern about the impact of biological invasions, our goal is to review the role of alien species introduced primarily for hunting purposes on the European scale. In particular, we explore: (1) the relative importance of game species in the context of alien species introductions; (2) the temporal evolution of the number of species introduced for hunting purposes; (3) the contribution of different taxa; (4) the pattern of introduced game species composition across countries (in terms of similarity), and (5) the underlying human demographic factors driving the diversity of introduced game species per country. According to our results, 24.3% of the mammals and 30.2% of the birds introduced into Europe during the last century were released primarily for hunting purposes, in total, 93 species (63 birds and 36 mammals), the most important taxa being Artiodactyls, Anseriformes and Galliformes. The species composition differed among countries, with a higher diversity of introduced game species in larger countries and in those with a higher human population density and proportion of hunters. This review stresses that hunting was a significant pathway for the introduction of invasive species into Europe in the last century. Since some of the game species introduced have had severe environmental impacts on many European regions, and introductions of non-native game species are still occurring, it is essential to improve regulations and increase public awareness regarding invasive game animals. This will help to preserve biodiversity and improve the sustainability of current hunting schemes in increasingly managed European ecosystems.
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