Chemical Abundances in Stars

Start year
2010
Organizational Unit

Related grants:

    General
    Description

    Stellar spectroscopy allows us to determine the properties and chemical compositions of stars. From this information for stars of different ages in the Milky Way, it is possible to reconstruct the chemical evolution of the Galaxy, as well as the origin of the elements heavier than boron, created mainly in stellar interiors. It is also possible to study stellar formation, and the formation of the Galaxy, from the signature of the Galactic potential on the stellar orbits, and the distributions of mass, ages, and the abundance of heavy elements.

    Obtaining high-resolution spectra, as necessary for studies of chemical compositions, requires advanced and efficient instrumentation. This is particularly true for research that calls for large stellar samples, which demands the observation of hundreds or thousands of sources simultaneously. Efficiency requires that the data processing and analysis are performed in an automated way.

    The interpretation of spectra is based on physical models of the atmospheres of the stars, from where the light that we observe escapes the stars. The main ingredients for building such models are the fluid dynamics, and the properties of the atoms, ions, and molecules, especially regarding their interactions with the radiation coming from the stellar interior.

    Once we have a plausible model, it is possible to compute in detail how the radiation propagates through the stellar atmosphere, and the emergent spectrum, which can then be iteratively compared with the observations to refine the model.

    This project covers three different research fronts:

    - Improving model atmospheres and simulations of stellar spectra.

    - Developing tools for acquisition, reduction, and analysis of spectroscopic observations, in particular for the determination of chemical abundances in stars.

    - Designing, preparing, and executing spectroscopic studies of stars aimed at understanding a) the most relevant aspects of the physics of stellar atmospheres, b) the formation and evolution of stars, c) the origin of the chemical elements, and d) the formation, structure, and evolution of the Milky Way galaxy.

    Principal investigator
    Project staff
    Collaborators
    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. Complete the installation and commissioning of HORuS on GTC
    2. Discover two new stars with more than 100,000 times less iron than the Sun
    3. Complete the classification of all the APOGEE spectra with K-means
    4. Publish a complete collection of model stellar spectra for stars O to M
    5. Identify the signature of chemical diffusion in the atmospheres of the stars in the cluster M67

    Related publications

    The ELM Survey. II. Twelve Binary White Dwarf Merger Systems 2011ApJ...727....3K
    The ELM Survey. I. A Complete Sample of Extremely Low-mass White Dwarfs 2010ApJ...723.1072B
    The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III 2011ApJS..193...29A
    The Apache Point Observatory Galactic Evolution Experiment: First Detection of High-velocity Milky Way Bar Stars 2012ApJ...755L..25N
    Spectroscopy from Photometry Using Sparsity: The SDSS Case Study 2010ApJ...719.1759A
    SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way, and Extra-Solar Planetary Systems 2011AJ....142...72E
    SDSS J163030.58+423305.8: a 40-min orbital period detached white dwarf binary 2011MNRAS.418L.157K
    New ATLAS9 and MARCS Model Atmosphere Grids for the Apache Point Observatory Galactic Evolution Experiment (APOGEE) 2012AJ....144..120M
    Metallicity gradients of disc stars for a cosmologically simulated galaxy 2011MNRAS.415.1469R
    Lithium Abundances in nearby FGK Dwarf and Subgiant Stars: Internal Destruction, Galactic Chemical Evolution, and Exoplanets 2012ApJ...756...46R
    Insight into the Formation of the Milky Way through Cold Halo Substructure. III. Statistical Chemical Tagging in the Smooth Halo 2012ApJ...749...77S
    Insight into the Formation of the Milky Way through Cold Halo Substructure. II. The Elemental Abundances of ECHOS 2011ApJ...734...49S
    Granulation Signatures in the Spectrum of the Very Metal-poor Red Giant HD 122563 2010ApJ...725L.223R
    Fundamental Parameters and Chemical Composition of Arcturus 2011ApJ...743..135R
    Faint Near-ultraviolet/Far-ultraviolet Standards from Swift/UVOT, GALEX, and SDSS Photometry 2010ApJ...725.1215S
    Circumstellar Material in Type Ia Supernovae via Sodium Absorption Features 2011Sci...333..856S
    Bridging model and observed stellar spectra 2011MNRAS.411..807A
    Accurate Masses for the Primary and Secondary in the Eclipsing White Dwarf Binary NLTT 11748 2010ApJ...721L.158K
    A 12 Minute Orbital Period Detached White Dwarf Eclipsing Binary 2011ApJ...737L..23B
    Rapid Orbital Decay in the 12.75-minute Binary White Dwarf J0651+2844 2012ApJ...757L..21H

    Related talks

    No related talks were found.

    Related conferences

    No related conferences were found.
    No related news were found.
    Related projects
    Optical bench
    HORuS - High Optical Resolution Spectrograph
    High-resolution spectrograph for the 10-m Gran Telescopio Canarias (GTC) based on components from UES, a spectrograph which was in use at the 4.2-m William Herschel Telescope (WHT) between 1992 and 2001.
    Carlos
    Allende Prieto
    Gran Telescopio Canarias (GTC)
    SEVERO OCHOA 2016 - 2019
    The IAC is an internationalized Spanish research centre aiming to achieve major advances in the understanding of the laws that govern the origin and evolution of the various forms of matter/energy in the Universe. Outstanding results are expected in key areas of research such as Solar physics, Sun-Earth connections, Exoplanetary systems, Solar
    Rafael
    Rebolo López