1,352 research outputs found

    Core-collapse supernovae ages and metallicities from emission-line diagnostics of nearby stellar populations

    Full text link
    Massive stars are the main objects that illuminate H II regions and they evolve quickly to end their lives in core-collapse supernovae (CCSNe). Thus it is important to investigate the association between CCSNe and H II regions. In this paper, we present emission line diagnostics of the stellar populations around nearby CCSNe, that include their host H II regions, from the PMAS/PPAK Integral-field Supernova hosts COmpilation (PISCO). We then use BPASS stellar population models to determine the age, metallicity and gas parameters for H II regions associated with CCSNe, contrasting models that consider either single star evolution alone or incorporate interacting binaries. We find binary-star models, that allow for ionizing photon loss, provide a more realistic fit to the observed CCSN hosts with metallicities that are closer to those derived from the oxygen abundance in O3N2. We also find that type II and type Ibc SNe arise from progenitor stars of similar age, mostly from 7 to 45 Myr, which corresponds to stars with masses < 20 solar mass . However these two types SNe have little preference in their host environment metallicity measured by oxygen abundance or in progenitor initial mass. We note however that at lower metallicities supernovae are more likely to be of type II.Comment: 22 pages, 19 Figures, 6 Tables. Accepted by MNRAS. Comments welcom

    La migració de les infermeres espanyoles des de l'inici de la crisi (2009-2014)

    Get PDF
    Paola Galbany, infermera, doctora en Ciències Infermeres i professora de la UAB, ha publicat un estudi sobre els efectes de la crisi en l'emigració dels professionals d'infermeria. L'atur i la precarietat laboral han forçat milers d'infermeres a emigrar en els últims anys a Europa, el què suposa una greu pèrdua de capital professional i humà per al país, un dels més longeus i que millor forma aquestes professionals.Paola Galbany, enfermera, doctora en Ciencias Enfermeras y profesora de la UAB, ha publicado un estudio sobre los efectos de la crisis en la emigración de las profesionales de la enfermería. El paro y la precariedad laboral han forzado a miles de ellas a emigrar en los últimos años, lo que supone una grave pérdida de capital profesional y humano para el país, uno de los más longevos y que mejor forma a estas profesionales

    Nursing care in Tuberculosis patients at a Spanish sanatorium, 1943-1975

    Get PDF
    The objective in this study is to identify the profile of the nursing staff, the work conditions and to describe nursing care at a sanatorium located in Barcelona, Spain between 1943 and 1975. historical study undertaken between 2008 and 2010, based on oral sources, five direct and one indirect testimonies, and the analysis of written documents. The data from the testimonies were collected through semistructured interviews. the nursing staff, mostly religious women, had scarce material and economic resources and no preventive measures to take care of the ill. The nurses undertook activities centered on the basic needs for physical and spiritual wellbeing. The study reveals how the nurses, despite working in hostile conditions, attempted to safeguard the wellbeing of the patients and accompany them during the death process

    Unresolved versus resolved: testing the validity of young simple stellar population models with VLT/MUSE observations of NGC 3603

    Full text link
    CONTEXT. Stellar populations are the building blocks of galaxies including the Milky Way. The majority, if not all extragalactic studies are entangled with the use of stellar population models given the unresolved nature of their observation. Extragalactic systems contain multiple stellar populations with complex star formation histories. However, their study is mainly based upon the principles of simple stellar populations (SSP). Hence, it is critical to examine the validity of SSP models. AIMS. This work aims to empirically test the validity of SSP models. This is done by comparing SSP models against observations of spatially resolved young stellar population in the determination of its physical properties, i.e. age and metallicity. METHODS. Integral field spectroscopy of a young stellar cluster in the Milky Way, NGC 3603, is used to study the properties of the cluster both as a resolved and unresolved stellar population. The unresolved stellar population is analysed using the Hα\alpha equivalent width as an age indicator, and the ratio of strong emission lines to infer metallicity. In addition, spectral energy distribution (SED) fitting using STARLIGHT, is used to infer these properties from the integrated spectrum. Independently, the resolved stellar population is analysed using the color-magnitude diagram (CMD) for age and metallicity determination. As the SSP model represents the unresolved stellar population, the derived age and metallicity are put to test whether they agree with those derived from resolved stars. RESULTS. The age and metallicity estimate of NGC 3603 derived from integrated spectroscopy are confirmed to be within the range of those derived from the CMD of the resolved stellar population, including other estimates found in the literature. The result from this pilot study supports the reliability of SSP models for studying unresolved young stellar populations.Comment: 9 pages, 5 figures, accepted to A&

    The pursuit of the Hubble Constant using Type II Supernovae

    Full text link
    The use of multiple independent methods with their own systematic uncertainties is crucial for resolving the ongoing tension between local and distant measurements of the Hubble constant (H0H_{0}). While type Ia supernovae (SNe Ia) have historically been the most widely used distance indicators, recent studies have shown that type II supernovae (SNe II) can provide independent measurements of extragalactic distances with different systematic uncertainties. Unlike SNe Ia, the progenitors of SNe II are well understood, arising from the explosion of red supergiants in late-type galaxies via core-collapse. While SNe II do not exhibit the same level of uniformity in peak luminosity as SNe Ia, their differences can be calibrated using theoretical or empirical methods. Overall, this chapter presents a comprehensive overview of the use of SNe II as extragalactic distance indicators, with a particular focus on their application to measuring H0H_0 and addressing the Hubble tension. We describe the underlying theory of each method, discuss the challenges associated with them, including uncertainties in the calibration of the supernova absolute magnitude, and present a comprehensive list of the most updated Hubble constant measurements.Comment: Invited chapter for the edited book "Hubble Constant Tension" (Eds. E. Di Valentino and D. Brout, Springer Singapore, expected in 2024

    SN 2019hcc: a Type II supernova displaying early O II lines

    Get PDF
    Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, as part of ePESSTO/ePESSTO+ (the extended Public ESO Spectroscopic Survey for Transient Objects Survey). ePESSTO+ observations were obtained under ESO program ID 1103.D-0328 (PI: Inserra). EP would like to thank Stuart Sim for useful discussion on the working of TARDIS. This research made use of TARDIS, a community-developed software package for spectral synthesis in supernovae (Kerzendorf & Sim 2014; Kerzendorf et al. 2019). The development of TARDIS received support from the Google Summer of Code initiative and from the European Space Agency's (ESA) Summer of Code in Space program. TARDIS makes extensive use ofAstropy and PyNE. TWC acknowledges the funding provided by the Alexander von Humboldt Foundation and the EUFunding underMarie SklodowskaCurie grant H2020-MSCA-IF-2018-842471. TMBwas funded by the Comisi ' on Nacional de Investigaci ' on Cient ' ifica y Tecnol ' ogica (CONICYT) PFCHA/DOCTORADOBECAS CHILE/2017-72180113. MG is supported by the Polish Narodowe Centrum Nauki (NCN) MAESTRO grant 2014/14/A/ST9/00121. MN is supported by a Royal Astronomical Society Research Fellowship. ACK: LG was funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 839090. This work has been partially supported by the Spanish grant PGC2018-095317-B-C21 within the European Funds for Regional Development (FEDER). GL is supported by a research grant (19054) from VILLUM FONDEN This work makes use of observations from the Las Cumbres Observatory (LCO) global telescope network. The LCO team is supported by National Science Foundation (NSF) grants AST1911225, AST-1911151, and NASA grant 80NSSC19K1639. This paper is also based on observations made with Swift (UVOT) and the Liverpool Telescope (LT). The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de losMuchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council (STFC). LCO data have been obtained via Optical Infrared Co-ordination Network for Astronomy (OPTICON) proposals (IDs: SUPA2020B-002 OPTICON 20B/003 and SUPA2019B-007 OPTICON 19B-009). The OPTICON project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 730890. Thiswork hasmade use of data from the AsteroidTerrestrialimpact Last Alert System (ATLAS) project. The ATLAS project is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the Near-Earth Object (NEO) search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen's University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Minist ' erio da Ciencia, Tecnologia e Inovaces (MCTI/LNA) do Brasil, the US National Science Foundation`s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). This work has made use of data from the Gamma-ray Burst Optical/Near-infrared Detector (GROND) instrument at the 2.2 MPE telescope at La Silla, Chile. Part of the funding for GROND (both hardware as well as personnel) was generously granted from the Leibniz-Prize to Prof. G. Hasinger (Deutsche Forschungsgemeinschaft (DFG) grant HA 1850/28-1). GROND data were obtained under European Southern Observatory (ESO) programme ID 0103.A-9099. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology. This research made use of Photutils, an Astropy package for detection and photometry of astronomical sources (Bradley et al. 2020). Based on data products from observations made with ESO Telescopes at the La Silla or Paranal Observatories under ESO programme ID 179.A-2010. IRAF is distributed by the National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation. This research made use of NUMPY (Harris et al. 2020), MATPLOTLIB (Hunter 2007), and ASTROPY (Astropy Collaboration 2013, 2018).We present optical spectroscopy together with ultraviolet, optical, and near-infrared photometry of SN 2019hcc, which resides in a host galaxy at redshift 0.044, displaying a sub-solar metallicity. The supernova spectrum near peak epoch shows a ‘w’ shape at around 4000 Å which is usually associated with OII lines and is typical of Type I superluminous supernovae. SN 2019hcc post-peak spectra show a well-developed Hα P-Cygni profile from 19 d past maximum and its light curve, in terms of its absolute peak luminosity and evolution, resembles that of a fast-declining Hydrogen-rich supernova (SN IIL). The object does not show any unambiguous sign of interaction as there is no evidence of narrow lines in the spectra or undulations in the light curve. Our TARDIS spectral modelling of the first spectrum shows that carbon, nitrogen, and oxygen (CNO) at 19 000 K reproduce the ‘w’ shape and suggests that a combination of non-thermally excited CNO and metal lines at 8000K could reproduce the feature seen at 4000 Å. The Bolometric light-curve modelling reveals that SN 2019hcc could be fit with a magnetar model, showing a relatively strong magnetic field (B > 3 × 1014 G), which matches the peak luminosity and rise time without powering up the light curve to superluminous luminosities. The high-energy photons produced by the magnetar would then be responsible for the detected OII lines. As a consequence, SN 2019hcc shows that a ‘w’ shape profile at around 4000 Å, usually attributed to OII, is not only shown in superluminous supernovae and hence it should not be treated as the sole evidence of the belonging to such a supernova type.European Organisation for Astronomical Research in the Southern Hemisphere, Chile, ePESSTO/ePESSTO+ extended Public ESO Spectroscopic Survey for Transient Objects Survey). ePESSTO+ observations were obtained under ESO program) 1103.D-0328Google IncorporatedEuropean Space Agency's (ESA) Summer of Code in Space programAlexander von Humboldt FoundationEU under Marie Sklodowska-Curie H2020-MSCA-IF-2018-842471Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CHILE/2017-72180113Polish Narodowe Centrum Nauki (NCN) MAESTRO grant 2014/14/A/ST9/00121Royal Astronomical Society Research FellowshipSKA South Africa 839090European Commission PGC2018-095317-B-C21VILLUM FONDEN 19054National Science Foundation (NSF) AST-1911225 AST-1911151National Aeronautics & Space Administration (NASA) 80NSSC19K1639 NN12AR55G 80NSSC18K0284 80NSSC18K1575UK Research & Innovation (UKRI)Science & Technology Facilities Council (STFC)European Union's Horizon 2020 research and innovation programme 730890Kepler/K2 grant J1944/80NSSC19K0112 HST GO-15889UK Research & Innovation (UKRI)Science & Technology Facilities Council (STFC) ST/T000198/1 ST/S006109/1Gaia Multilateral AgreementGRONDGerman Research Foundation (DFG) HA 1850/28-1European Southern Observatory (ESO) programme 0103.A-9099National Aeronautics & Space Administration (NASA)ESO Telescopes at the La Silla or Paranal Observatories under ESO programme 179.A-201

    Uncertainties in gas kinematics arising from stellar continuum modelling in integral field spectroscopy data: the case of NGC2906 observed with MUSE/VLT

    Full text link
    We study how the use of several stellar subtraction methods and line fitting approaches can affect the derivation of the main kinematic parameters (velocity and velocity dispersion fields) of the ionized gas component. The target of this work is the nearby galaxy NGC 2906, observed with the MUSE instrument at Very Large Telescope. A sample of twelve spectra is selected from the inner (nucleus) and outer (spiral arms) regions, characterized by different ionization mechanisms. We compare three different methods to subtract the stellar continuum (FIT3D, STARLIGHT and pPXF), combined with one of the following stellar libraries: MILES, STELIB and GRANADA+MILES. The choice of the stellar subtraction method is the most important ingredient affecting the derivation of the gas kinematics, followed by the choice of the stellar library and by the line fitting approach. In our data, typical uncertainties in the observed wavelength and width of the H\alpha and [NII] lines are of the order of _rms \sim 0.1\AA\ and _rms \sim 0.2\AA\ (\sim 5 and 10km/s, respectively). The results obtained from the [NII] line seem to be slightly more robust, as it is less affected by stellar absorption than H\alpha. All methods considered yield statistically consistent measurements once a mean systemic contribution \Delta\bar\lambda=\Delta\bar\sigma=0.2xDelta_{MUSE} is added in quadrature to the line fitting errors, where \Delta_{MUSE} = 1.1\AA\ \sim 50 km/s denotes the instrumental resolution of the MUSE spectra. Although the subtraction of the stellar continuum is critical in order to recover line fluxes, any method (including none) can be used in order to measure the gas kinematics, as long as an additional component of 0.2 x Delta_MUSE is added to the error budget.Comment: 20 pages, 14 figure

    Pseudognaphalium aldunateoides de nuevo bajo Gnaphalium (Compositae: Gnaphalieae)

    Get PDF
    Generic classification of some members of the tribe Gnaphalieae (Compositae) and in particular the generic delimitation of the old genus Gnaphalium has been long problematic. The genus Pseudognaphalium was first split from Gnaphalium based on morphology and later supported by molecular phylogenies. However, the generic identity of some species remains doubtful. Here we provide a morphological study of Pseudognaphalium aldunateoides, which is compared with the type species of Gnaphalium (Gnaphalium uliginosum) and Pseudognaphalium (Gnaphalium oxyphyllum). We also include the three species in a nuclear ribosomal DNA (nrDNA) and a plastid (cpDNA) molecular phylogeny of the tribe Gnaphalieae. Our results show that P. aldunateoides has a dimorphic pappus, character not present in the genus Pseudognaphalium but characteristic of the genus Gnaphalium. It also shows a stereome with intermediate features between the undivided stereome typical of Gnaphalium and the fenestrated stereome typical of Pseudognaphalium. In the nrDNA and the cpDNA trees, P. aldunateoides is placed within the Gnaphalium s. str. clade, not closely related to Pseudognaphalium. With all these evidence, we conclude that P. aldunateoides is correctly placed in Gnaphalium.La clasificación genérica de varios miembros de la tribu Gnaphalieae (Compositae) y en particular la delimitación genérica del antiguo género Gnaphalium ha sido problemática durante mucho tiempo. El género Pseudognaphalium fue escindido de Gnaphalium por su morfología lo que después fue apoyado por filogenias moleculares. Sin embargo, la identidad genérica de algunas especies todavía es dudosa. Aquí aportamos un estudio morfológico de Pseudognaphalium aldunateoides, que es comparado con las especies tipo de los géneros Gnaphalium (Gnaphalium uliginosum) y Pseudognaphalium (Gnaphalium oxyphyllum). También hemos incluido estas tres especies en filogenias moleculares de la tribu Gnaphalieae basadas en ADN ribosómico nuclear y ADN cloroplástico. Nuestros resultados muestran que P. aldunateoides tiene el vilano dimórfico, carácter que no está presente en el género Pseudognaphalium pero que, sin embargo, es característico del género Gnaphalium. Además, su estereoma muestra características intermedias entre el estereoma no dividido típico del género Gnaphalium y el estereoma fenestrado típico del género Pseudognaphalium. En ambas filogenias, P. aldunateoides se sitúa dentro del clado Gnaphalium s. str., no próximamente emparentado con Pseudognaphalium. Con todas estas evidencias concluimos que P. aldunateoides se clasifica correctamente dentro de Gnaphalium
    • …
    corecore