Abundancias Químicas en Estrellas

Año de inicio
2010
Unidad organizativa

Subvenciones relacionadas:

    General
    Descripción

    La espectroscopía de estrellas nos permite determinar las propiedades y composiciones químicas de las mismas. A partir de esta información para estrellas de diferente edad en la Vía Láctea es posible reconstruir la evolución química de la Galaxia, así como el origen de los elementos más pesados que el boro, forjados principalmente en los interiores estelares. También es posible estudiar la formación estelar, y la de la propia Galaxia, a través de la huella que deja el potencial Galáctico en las órbitas de las estrellas, y de las distribuciones de masa, edad y la abundancia de elementos pesados.

    La obtención de espectros con alta resolución espectral, apropiados para estudios de la composición química, requiere instrumentación sofisticada y eficiente. Esto es especialmente cierto en investigaciones en las que se necesitan extensas muestras de estrellas, que exigen observar cientos, o incluso miles de fuentes de forma simultánea. El procesado y análisis de los datos debe ser automatizado para ser igualmente eficiente.

    La interpretación de los espectros se basa en modelos físicos de las atmósferas de las estrellas, de donde se escapa la luz que observamos. Los ingredientes fundamentales para la construcción de estos modelos son la dinámica de fluidos, y las propiedades de los átomos, iones y moléculas, especialmente en lo que se refiere a sus interacciones con la radiación que proviene del interior estelar. Una vez que se tiene un modelo plausible, es posible calcular de forma detallada cómo se propaga la radiación a través de la atmósfera estelar, y el espectro emergente, para, de forma iterativa, compararlo con las observaciones y refinar el modelo.

    Este Proyecto incluye tres diferentes frentes de investigación:

    - La mejora de los modelos de atmósfera y las simulaciones de espectros estelares.

    - El desarrollo de herramientas para la obtención, reducción y el análisis de observaciones espectroscópicas, y en particular para la determinación de abundancias químicas en estrellas.

    - El diseño, preparación, y ejecución de estudios espectroscópicos de estrellas con el fin de entender a) los aspectos más relevantes de la física de las atmósferas estelares, b) la formación y evolución de las estrellas, c) el origen de los elementos químicos y d) la formación, estructura y evolución química de la Vía Láctea.

    Investigador principal
    Personal del proyecto
    Colaboradores
    Dr.
    I. Hubeny
    Dr.
    B. Castanheira
    Dr.
    M. Kilic
    Dr.
    S. Majewski
    Dr.
    H.G. Ludwig
    Dr.
    M. Cropper
    Dr.
    M. P. Ruffoni
    Dr.
    J. C. Pickering
    Dr.
    K. Cunha
    Dr.
    Andrew Cooper
    Dr.
    Boris Gaensicke
    1. Completar la instalación y pruebas de HORuS en GTC
    2. Descubrir dos nuevas estrellas con abundancias de hierro inferiores a 100.000 veces el valor solar
    3. Completar la clasificación de los espectros de APOGEE con K-means
    4. Publicar una colección completa de espectros modelo para estrellas O a M
    5. Identificar la huella de la difusión química en las atmósferas de estrellas del cúmulo M67

    Publicaciones relacionadas

    • Gaia Data Release 2. Processing the spectroscopic data

      Context. The Gaia Data Release 2 (DR2) contains the first release of radial velocities complementing the kinematic data of a sample of about 7 million relatively bright, late-type stars. Aims: This paper provides a detailed description of the Gaia spectroscopic data processing pipeline, and of the approach adopted to derive the radial velocities

      Sartoretti, P. et al.

      Fecha de publicación:

      8
      2018
      Número de citas
      118
    • Gaia Data Release 2. Calibration and mitigation of electronic offset effects in the data

      Context. The European Space Agency's Gaia satellite was launched into orbit around L2 in December 2013. This ambitious mission has strict requirements on residual systematic errors resulting from instrumental corrections in order to meet a design goal of sub-10 microarcsecond astrometry. During the design and build phase of the science instruments

      Hambly, N. C. et al.

      Fecha de publicación:

      8
      2018
      Número de citas
      33
    • A Chemical and Kinematical Analysis of the Intermediate-age Open Cluster IC 166 from APOGEE and Gaia DR2

      IC 166 is an intermediate-age open cluster (OC) (˜1 Gyr) that lies in the transition zone of the metallicity gradient in the outer disk. Its location, combined with our very limited knowledge of its salient features, make it an interesting object of study. We present the first high-resolution spectroscopic and precise kinematical analysis of IC 166

      Schiappacasse-Ulloa, J. et al.

      Fecha de publicación:

      9
      2018
      Número de citas
      8
    • APOGEE Data Releases 13 and 14: Data and Analysis

      The data and analysis methodology used for the SDSS/APOGEE Data Releases 13 and 14 are described, highlighting differences from the DR12 analysis presented in Holtzman et al. Some improvement in the handling of telluric absorption and persistence is demonstrated. The derivation and calibration of stellar parameters, chemical abundances, and

      Holtzman, J. A. et al.

      Fecha de publicación:

      9
      2018
      Número de citas
      224
    • APOGEE Data Releases 13 and 14: Stellar Parameter and Abundance Comparisons with Independent Analyses

      Data from the SDSS-IV/Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) have been released as part of SDSS Data Releases 13 (DR13) and 14 (DR14). These include high-resolution H-band spectra, radial velocities, and derived stellar parameters and abundances. DR13, released in 2016 August, contained APOGEE data for roughly 150,000

      Jönsson, H. et al.

      Fecha de publicación:

      9
      2018
      Número de citas
      116
    • Testing models of stellar structure and evolution - I. Comparison with detached eclipsing binaries

      We present the results of an analysis aimed at testing the accuracy and precision of the PARSEC v1.2S library of stellar evolution models, combined with a Bayesian approach, to infer stellar parameters. We mainly employ the online DEBCat catalogue by Southworth, a compilation of detached eclipsing binary systems with published measurements of

      del Burgo, C. et al.

      Fecha de publicación:

      9
      2018
      Número de citas
      24
    • Stellar and Planetary Characterization of the Ross 128 Exoplanetary System from APOGEE Spectra

      The first detailed chemical abundance analysis of the M-dwarf (M4.0) exoplanet-hosting star Ross 128 is presented here, based upon near-infrared (1.5–1.7 μm), high-resolution (R ∼ 22,500) spectra from the SDSS Apache Point Galactic Evolution Experiment survey. We determined precise atmospheric parameters T eff = 3231 ± 100 K, log g = 4.96 ± 0.11

      Souto, D. et al.

      Fecha de publicación:

      6
      2018
      Número de citas
      21
    • Signatures of the Galactic bar on stellar kinematics unveiled by APOGEE

      Bars are common galactic structures in the local universe that play an important role in the secular evolution of galaxies, including the Milky Way. In particular, the velocity distribution of individual stars in our galaxy is useful to shed light on stellar dynamics, and provides information complementary to that inferred from the integrated light

      Palicio, P. A. et al.

      Fecha de publicación:

      7
      2018
      Número de citas
      9
    • Chemical Composition of Two Bright, Extremely Metal-poor Stars from the SDSS MARVELS Pre-survey

      SDSS J082625.70+612515.10 (V = 11.4 [Fe/H] = ‑3.1) and SDSS J134144.60+474128.90 (V = 12.4 [Fe/H] = ‑3.2) were observed with the SDSS 2.5m telescope as part of the SDSS MARVELS spectroscopic pre-survey and identified as extremely metal-poor (EMP; [Fe/H]

      Bandyopadhyay, A. et al.

      Fecha de publicación:

      6
      2018
      Número de citas
      9
    • Machine learning in APOGEE. Unsupervised spectral classification with K-means

      Context. The volume of data generated by astronomical surveys is growing rapidly. Traditional analysis techniques in spectroscopy either demand intensive human interaction or are computationally expensive. In this scenario, machine learning, and unsupervised clustering algorithms in particular, offer interesting alternatives. The Apache Point

      Garcia-Dias, R. et al.

      Fecha de publicación:

      5
      2018
      Número de citas
      13
    • Disk stars in the Milky Way detected beyond 25 kpc from its center

      Context. The maximum size of the Galactic stellar disk is not yet known. Some studies have suggested an abrupt drop-off of the stellar density of the disk at Galactocentric distances R ≳ 15 kpc, which means that in practice no disk stars or only very few of them should be found beyond this limit. However, stars in the Milky Way plane are detected

      López-Corredoira, M. et al.

      Fecha de publicación:

      5
      2018
      Número de citas
      19
    • The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment

      The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014–2016 July) public

      Abolfathi, B. et al.

      Fecha de publicación:

      4
      2018
      Número de citas
      890
    • Chemical Abundances of Main-sequence, Turnoff, Subgiant, and Red Giant Stars from APOGEE Spectra. I. Signatures of Diffusion in the Open Cluster M67

      Detailed chemical abundance distributions for 14 elements are derived for eight high-probability stellar members of the solar metallicity old open cluster M67 with an age of ∼4 Gyr. The eight stars consist of four pairs, with each pair occupying a distinct phase of stellar evolution: two G dwarfs, two turnoff stars, two G subgiants, and two red

      Souto, D. et al.

      Fecha de publicación:

      4
      2018
      Número de citas
      55
    • The Metal-poor non-Sagittarius (?) Globular Cluster NGC 5053: Orbit and Mg, Al, and Si Abundances

      Metal-poor globular clusters (GCs) exhibit intriguing Al–Mg anti-correlations and possible Si–Al correlations, which are important clues to decipher the multiple-population phenomenon. NGC 5053 is one of the most metal-poor GCs in the nearby universe and has been suggested to be associated with the Sagittarius (Sgr) dwarf galaxy, due to its

      Tang, B. et al.

      Fecha de publicación:

      3
      2018
      Número de citas
      23
    • J0023+0307: A Mega Metal-poor Dwarf Star from SDSS/BOSS

      Only a handful of stars have been identified with an iron abundance [Fe/H]

      Aguado, D. S. et al.

      Fecha de publicación:

      2
      2018
      Número de citas
      46
    • Stellar Multiplicity Meets Stellar Evolution and Metallicity: The APOGEE View

      We use the multi-epoch radial velocities acquired by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey to perform a large-scale statistical study of stellar multiplicity for field stars in the Milky Way, spanning the evolutionary phases between the main sequence (MS) and the red clump. We show that the distribution of

      Badenes, C. et al.

      Fecha de publicación:

      2
      2018
      Número de citas
      116
    • A view of the H-band light-element chemical patterns in globular clusters under the AGB self-enrichment scenario

      We discuss the self-enrichment scenario by asymptotic giant branch (AGB) stars for the formation of multiple populations in globular clusters (GCs) by analysing data set of giant stars observed in nine Galactic GCs, covering a wide range of metallicities and for which the simultaneous measurements of C, N, O, Mg, Al, and Si are available. To this

      Dell'Agli, F. et al.

      Fecha de publicación:

      4
      2018
      Número de citas
      25
    • An UXor among FUors: Extinction-related Brightness Variations of the Young Eruptive Star V582 Aur

      V582 Aur is an FU Ori-type young eruptive star in outburst since ∼1985. The eruption is currently in a relatively constant plateau phase, with photometric and spectroscopic variability superimposed. Here we will characterize the progenitor of the outbursting object, explore its environment, and analyze the temporal evolution of the eruption. We are

      Ábrahám, P. et al.

      Fecha de publicación:

      1
      2018
      Número de citas
      22
    • A photometric study of globular clusters observed by the APOGEE survey

      In this paper, we describe the photometric and spectroscopic properties of multiple populations in seven northern globular clusters. In this study, we employ precise ground-based photometry from the private collection of Stetson, space photometry from the Hubble Space Telescope (HST), literature abundances of Na and O, and Apache Point Observatory

      Mészáros, Sz. et al.

      Fecha de publicación:

      4
      2018
      Número de citas
      5
    • Disentangling the Galactic Halo with APOGEE. I. Chemical and Kinematical Investigation of Distinct Metal-poor Populations

      We find two chemically distinct populations separated relatively cleanly in the [Fe/H]–[Mg/Fe] plane, but also distinguished in other chemical planes, among metal-poor stars (primarily with metallicities [{Fe}/{{H}}]< -0.9) observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and analyzed for Data Release 13 (DR13) of the

      Hayes, C. R. et al.

      Fecha de publicación:

      1
      2018
      Número de citas
      125

    Charlas relacionadas

    No se han encontrado charlas relacionadas.

    Congresos relacionados

    No se han encontrado congresos relacionados.
    Proyectos relacionados
    banco óptico
    HORuS - High Optical Resolution Spectrograph

    Espectrógrafo de alta resolución en operación en el Gran Telescopio Canarias (GTC) de 10m. usando componentes del espectrógrafo UES, utilizado en el Telescopio William Herschel (WHT) de 4.2 m. entre los años 1992 y 2001.

    Carlos
    Allende Prieto
    Gran Telescopio Canarias (GTC)
    SEVERO OCHOA 2016 - 2019

    El Gobierno español concede la Acreditación como Centro de Excelencia Severo Ochoa con el fin de reconocer, premiar y promover la investigación científica de alto nivel en los centros y unidades españoles que tengan un alto nivel de excelencia en el ámbito internacional. Los objetivos específicos del Programa Severo Ochoa son: - Mejorar la

    Rafael
    Rebolo López