1,967 research outputs found

    Detection and Mapping of Decoupled Stellar and Ionized Gas Structures in the Ultraluminous Infrared Galaxy IRAS 12112+0305

    Get PDF
    Integral field optical spectroscopy with the INTEGRAL fiber-fed system and HST optical imaging are used to map the complex stellar and warm ionized gas structure in the ultraluminous infrared galaxy IRAS 12112+0305. Images reconstructed from wavelength-delimited extractions of the integral field spectra reveal that the observed ionized gas distribution is decoupled from the stellar main body of the galaxy, with the dominant continuum and emission-line regions separated by projected distances of up to 7.5 kpc. The two optical nuclei are detected as apparently faint emission-line regions, and their optical properties are consistent with being dust-enshrouded weak-[OI] LINERs. The brightest emission-line region is associated with a faint (m_{I}= 20.4), giant HII region of 600 pc diameter, where a young (about 5 Myr) massive cluster of about 2 ×\times 107^7 MM_{\odot} dominates the ionization. Internal reddening towards the line-emitting regions and the optical nuclei ranges from 1 to 8 magnitudes, in the visual. Taken the reddening into aacount, the overall star formation in IRAS 12112+0305 is dominated by starbursts associated with the two nuclei and corresponding to a star formation rate of 80 MM_{\odot} yr1^{-1}.Comment: 2 figures, accepted to Ap.J. Letter

    The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope V. Optimal algorithms for planning multi-object spectroscopic observations

    Full text link
    We present an overview of the capabilities and key algorithms employed in the so-called eMPT software suite developed for planning scientifically optimized, multi-object spectroscopic (MOS) observations with the Micro-Shutter Array (MSA) of the Near-Infrared Spectrograph (NIRSpec) instrument on board the James Webb Space Telescope (JWST), the first multi-object spectrograph to operate in space. NIRSpec MOS mode is enabled by a programmable MSA, a regular grid of ~250,000 individual apertures that projects to a static, semi-regular pattern of available slits on the sky and makes the planning and optimization of an MSA observation a rather complex task. As such, the eMPT package is offered to the NIRSpec user community as a supplement to the MSA Planning Tool (MPT) included in the STScI Astronomer's Proposal Tool (APT) to assist in the planning of NIRSpec MOS proposals requiring advanced functionality to meet ambitious science goals. The eMPT produces output that can readily be imported and incorporated into the user's observing program within the APT to generate a customized MPT MOS observation. Furthermore, its novel algorithms and modular approach make it highly flexible and customizable, providing users the option to finely control the workflow and even insert their own software modules to tune their MSA slit masks to the particular scientific objectives at hand

    Abundance data for invertebrate assemblages from intertidal mussel beds along the Atlantic Canadian coast

    Get PDF
    This data set describes the abundance of 50 invertebrate taxa found in intertidal mussel beds along the Atlantic Canadian coast. This information resulted from a regionalscale study that investigated the effects of wave exposure on the richness and composition of invertebrate assemblages from intertidal mussel beds. Abundance data are provided for taxa representing the Annelida, Arthropoda, Bryozoa, Chordata, Cnidaria, Echinodermata, Mollusca, Nematoda, Nemertea, and Platyhelminthes. The data characterize mussel beds from wave-sheltered and wave-exposed locations spanning 315 km of the coast of Nova Scotia. Univariate and multivariate analyses revealed that the compositional structure of these invertebrate assemblages differed markedly depending on wave exposure. Overall, because of its taxonomic diversity, the inclusion of data for basal, intermediate, and top trophic levels, and the coverage of two extremes of environmental stress, this data set could be useful to test broader aspects of ecological theory. Areas of ecology that could advance using this data set are those concerning environmental stress models of community organization, abundance–occupancy relationships, species co-occurrence, species abundance distributions, dominance and rarity, spatial scales of population and community variation, and distribution of functional and phylogenetic diversity. Use of this data set for academic or educational purposes is allowed as long as the data source is properly cited. When used for academic or educational purposes, this data set should be cited using the title of this Data Paper, the names of the authors, the year of publication, and the corresponding volume and article numbers

    Recurrence of the blue wing enhancements in the high ionization lines of SDSS 1004+4112 A

    Get PDF
    We present integral field spectroscopic observations of the quadruple-lensed QSO SDSS 1004+4112 taken with the fiber system INTEGRAL at the William Herschel Telescope on 2004 January 19. In May 2003 a blueward enhancement in the high ionization lines of SDSS 1004+4112A was detected and then faded. Our observations are the first to note a second event of similar characteristics less than one year after. Although initially attributed to microlensing, the resemblance among the spectra of both events and the absence of microlensing-induced changes in the continuum of component A are puzzling. The lack of a convincing explanation under the microlensing or intrinsic variability hypotheses makes the observed enhancements particularly relevant, calling for close monitoring of this object.Comment: 4 pages, 5 figure

    The mitogenome of Hydropsyche pellucidula (Hydropsychidae): first gene arrangement in the insect order Trichoptera

    Get PDF
    International audienceWe describe the mitochondrial genome of Hydropsyche pellucidula Curtis 1834, which is first described for the suborder Annulipalpia and the first in the order Trichoptera to show a non-canonical gene order. The mitogenome was obtained by de novo assembly of shotgun sequenced total genomic DNA using Illumina Miseq technology, which produced an average coverage of 115× and a minimum coverage of 48×. The mitochondrial genome includes 13 protein-coding genes, 2 rRNAs and 22 tRNAs. The genome is characterized by a rearrangement in the relative position of protein-coding and ribosomal genes. This mitogenome sequence will be useful for studying the family Hydropsychidae, which is commonly used for freshwater pollution biomonitoring

    Metropolitan Mobility In Spain Are We Tending Towards Sustainability?

    Get PDF
    There is a growing concern in the urban transport field about the development of a data set of indicators that would allow to undertake ongoing monitoring and evaluation of current transportation policies, compare data from territories facing the same kind of challenges, identify good practices and strategies to be followed, and strengthen the information, participation and decision-making process. These data set of indicators, known as observatories, are aimed to fulfil stakeholders needs, so that they achieve the precise knowledge to adopt pertinent policies. The Spanish Metropolitan Mobility Observatory, sponsored by the Spanish Ministry of Environment, was launched in 2003 by the Metropolitan Transport Authorities of the major metropolitan areas in Spain, and TRANSyT. Its scope is to identify those elements within urban transport policy packages which have had a more significant impact on mobility (i.e. global transport demand, travel time, modal split,…), and on land use patterns. And its main goal is to serve as basis for Metropolitan Transport Authorities to improve operation of their public transport system, and thus increasing their contribution to sustainable mobility. For itsFor its second edition, based on the year 2003, a set of data from the different Metropolitan Transport Authorities has been collected, in order to: Highlight public transport contribution to improve urban areas and sustainable development - Describe the role of Metropolitan Transport Authorities in achieving an attractive and quality public transport - Monitoring transport supply and demand characteristics, focusing on public transport - Analyse resources dedicated to the public transport system - Describe the financial models used for the public transport system - Highlight the main initiatives and innovations developed by Metropolitan areas This information will be compared to that one from the previous edition, and a statistical analysis will be conducted in order to identify those variables, which are likely to explainresults in most cities.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

    Metropolitan Mobility In Spain Are We Tending Towards Sustainability?

    Get PDF
    Workshop FThere is a growing concern in the urban transport field about the development of a data set of indicators that would allow to undertake ongoing monitoring and evaluation of current transportation policies, compare data from territories facing the same kind of challenges, identify good practices and strategies to be followed, and strengthen the information, participation and decision-making process. These data set of indicators, known as observatories, are aimed to fulfil stakeholders needs, so that they achieve the precise knowledge to adopt pertinent policies. The Spanish Metropolitan Mobility Observatory, sponsored by the Spanish Ministry of Environment, was launched in 2003 by the Metropolitan Transport Authorities of the major metropolitan areas in Spain, and TRANSyT. Its scope is to identify those elements within urban transport policy packages which have had a more significant impact on mobility (i.e. global transport demand, travel time, modal split,…), and on land use patterns. And its main goal is to serve as basis for Metropolitan Transport Authorities to improve operation of their public transport system, and thus increasing their contribution to sustainable mobility. For itsFor its second edition, based on the year 2003, a set of data from the different Metropolitan Transport Authorities has been collected, in order to: Highlight public transport contribution to improve urban areas and sustainable development - Describe the role of Metropolitan Transport Authorities in achieving an attractive and quality public transport - Monitoring transport supply and demand characteristics, focusing on public transport - Analyse resources dedicated to the public transport system - Describe the financial models used for the public transport system - Highlight the main initiatives and innovations developed by Metropolitan areas This information will be compared to that one from the previous edition, and a statistical analysis will be conducted in order to identify those variables, which are likely to explainresults in most cities.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

    Energy Storage Systems for Electric Vehicles: Performance Comparison based on a Simple Equivalent Circuit and Experimental Tests

    Full text link
    The decision to select the most suitable type of energy storage system for an electric vehicle is always difficult, since many conditionings must be taken into account. Sometimes, this study can be made by means of complex mathematical models which represent the behavior of a battery, ultracapacitor or some other devices. However, these models are usually too dependent on parameters that are not easily available, which usually results in nonrealistic results. Besides, the more accurate the model, the more specific it needs to be, which becomes an issue when comparing systems of different nature. This paper proposes a practical methodology to compare different energy storage technologies. This is done by means of a linear approach of an equivalent circuit based on laboratory tests. Via these tests, the internal resistance and the self-discharge rate are evaluated, making it possible to compare different energy storage systems regardless their technology. Rather simple testing equipment is sufficient to give a comparative idea of the differences between each system, concerning issues such as efficiency, heating and self-discharge, when operating under a certain scenario. The proposed methodology is applied to four energy storage systems of different nature for the sake of illustration
    corecore