Login

NBIA Workshop on Radiation Transfer in Astrophysics

6–10 Jun 2022
Europe/Copenhagen timezone

Email inquiries to

Session

Stellar atmospheres

6 Jun 2022, 13:45

Presentation materials

There are no materials yet.

  1. 52. The Multi3D extension for DISPATCH: A task based approach to NLTE radiative transfer
    Richard Hoppe (MPIA Heidelberg)
    06/06/2022, 14:00
    Stellar Atmospheres
    Talk

    With next-generation astronomical facilities like WEAVE, 4MOST, and SDSS-V large datasets of high-quality stellar spectra will become available soon. The need for cutting edge 3D non-LTE radiative transfer codes is clear, but the demand for easy-to-use spectrum synthesis tools is even greater. We aim to provide both by supplying a non-LTE RT module based on the Multi3D code to the recently...

    Go to contribution page
  2. 31. 3D non-LTE radiative transfer in the solar atmosphere
    Jorrit Leenaarts
    06/06/2022, 14:20
    Stellar Atmospheres
    Talk

    Predictions made by radiation-MHD simulations of the solar atmosphere can be tested by comparing the emergent spectrum to observations. Comparison with observations of the intensity in spectral lines that form in the chromosphere require that non-LTE, non-equilibrium, 3D effects, and partially coherent scattering play important roles. If comparison with the full Stokes vector is required, then...

    Go to contribution page
  3. 75. Non-LTE stellar physics and its applications
    Ekaterina Magg (MPIA)
    06/06/2022, 15:30
    Stellar Atmospheres
    Talk

    One of the biggest assumptions in modelling stellar emission has been an assumption of local thermodynamical equilibrium, also known as LTE. While still widely spread, it has been shown to significantly bias results of stellar modelling, for example derived abundances.
    In this talk I will focus on what is known as Non-LTE modelling - modelling stellar radiation without assuming LTE.
    I will...

    Go to contribution page
  4. 53. Modelling the Milky Way's most metal-poor star
    Cis Lagae (Stockholm University)
    06/06/2022, 16:00
    Stellar Atmospheres
    Talk

    Late-type ultra metal-poor stars are thought to be formed from interstellar gas enriched by only one to few supernovae. As such, their elemental abundances and total metal content are important in understanding the limits of star formation in the early universe and the chemical evolution of the Milky Way. In this talk, I will present an updated chemical abundance analysis of the most...

    Go to contribution page
  5. 55. The handling of radiation transport in 3D simulations of cool giants
    Arief Ahmad (Uppsala University)
    06/06/2022, 16:20
    Stellar Atmospheres
    Talk

    Recent 3D simulations of cool giants and supergiants, specifically the asymptotic giant branch (AGB) and red supergiant (RSG) stars, with the CO5BOLD radiation-hydrodynamics code cover a wider range of stellar parameters and with greater temporal and spatial resolution than before. In these simulations, the hydrodynamical steps were handled straightforwardly with the Roe solver with 1D...

    Go to contribution page
  6. 74. Solar atmospheric modelling and diagnostics
    Mats Carlsson
    08/06/2022, 13:30
    Stellar Atmospheres
    Talk

    Radiation is the dominant energy transport mechanism in the solar atmosphere, and it is therefore important to have a good description of radiative transfer when modelling the solar atmosphere. For modelling purposes, it is only important to capture the radiative cooling/heating and not the details of the spectrum. For diagnostic purposes, we need the detailed spectrum and 3D radiative...

    Go to contribution page
  7. 94. Non-LTE impact of Ti I and Ti II on metal-poor type star abundances
    Mallinson Jack
    08/06/2022, 14:00
  8. 95. Stellar atmospheres
    Tatyana Sitnova
    08/06/2022, 14:20

    Title: Non-LTE zinc abundance in different spectral type stars and Galactic [Zn/Fe] trend
    Abstract: We present the non-LTE line formation calculations for Zn I-II in stars in a wide range of spectral types. The most accurate atomic data available to date were adopted, namely, quantum mechanical rate coefficients for inelastic collisions with hydrogen atoms and electronic collisions, and...

    Go to contribution page
Building timetable...