Non-LTE Radiative Transfer with Turbospectrum

Abstract

Physically realistic models of stellar spectra are needed in a variety of astronomical studies, from the analysis of fundamental stellar parameters, to studies of exoplanets and stellar populations in galaxies. Here we present a new version of the widely-used radiative transfer code Turbospectrum, which we update with the capacity to perform spectrum synthesis for lines of multiple chemical elements in Non-Local Thermodynamic Equilibrium (NLTE). We use the code in the analysis of metallicites and abundances of the Gaia FGK benchmark stars, using one-dimensional MARCS atmospheric models and the averages of 3D radiation-hydrodynamics simulations of stellar surface convection. We show that the new more physically realistic models offer a better description of the observed data and make the program and the associated microphysics data publicly available, including grids of NLTE departure coefficients for H, O, Na, Mg, Si, Ca, Ti, Mn, Fe, Co, Ni, Sr, and Ba.

References in corpus (46)

• The chemical composition of the Sun
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The NextGen Model Atmosphere grid for $3000\le \Teff \le 10000\K$
• First stars V - Abundance patterns from C to Zn and supernova yields in the early Galaxy
• The GALAH+ Survey: Third Data Release
• Spectroscopy Made Easy: Evolution
• Simulations of stellar convection with CO5BOLD
• Non-LTE calculations for neutral Na in late-type stars using improved atomic data
• NLTE line formation of Fe for late-type stars. I. Standard stars with 1D and <3D> model atmospheres
• Gaia FGK Benchmark Stars - Metallicity
• The Abundances of Neutron Capture Species in the Very Metal-Poor Globular Cluster M15: An Uniform Analysis of RGB and RHB Stars
• Gaia FGK Benchmark Stars: Effective temperatures and surface gravities
• The formation of the Halpha line in the solar chromosphere
• The Stagger-grid: A Grid of 3D Stellar Atmosphere Models - I. Methods and General Properties
• Observational constraints on the origin of the elements. IV: The standard composition of the Sun
• A non-LTE study of neutral and singly-ionized calcium in late-type stars
• Non-LTE line formation of Fe in late-type stars - III. 3D non-LTE analysis of metal-poor stars
• Atomic data for the Gaia-ESO Survey
• NLTE analysis of Co I/Co II lines in spectra of cool stars with new laboratory hyperfine splitting constants
• The APOGEE Data Release 16 Spectral Line List
• Observational constraints on the origin of the elements. I. 3D NLTE formation of Mn lines in late-type stars
• The Gaia FGK Benchmark Stars - High resolution spectral library
• Ionization balance of Ti in the photospheres of the Sun and four late-type stars
• Non-LTE line formation for heavy elements in four very metal-poor stars
• Red Supergiant Stars as Cosmic Abundance Probes: II. NLTE Effects in J-band Silicon Lines
• Fe I Oscillator Strengths for the Gaia-ESO Survey
• Non-local thermodynamic equilibrium stellar spectroscopy with 1D and <3D> models - I. Methods and application to magnesium abundances in standard stars
• NLTE analysis of Sr lines in spectra of late-type stars with new R-matrix atomic data
• The GALAH Survey: Non-LTE departure coefficients for large spectroscopic surveys
• Solar oxygen abundance
• Fe I Oscillator Strengths for Transitions from High-lying Even-Parity Levels
• Why one-dimensional models fail in the diagnosis of average spectra from inhomogeneous stellar atmospheres
• Non-LTE line formation of Fe in late-type stars IV: Modelling of the solar centre-to-limb variation in 3D
• Inelastic O+H collisions and the OI 777nm solar centre-to-limb variation
• NLTE model calculations for the solar atmosphere with an iterative treatment of opacity distribution functions
• The Stagger-grid: A Grid of 3D Stellar Atmosphere Models - II. Horizontal and Temporal Averaging and Spectral Line Formation
• NLTE Chemical abundances in Galactic open and globular clusters
• Observational constraints on the origin of the elements II. 3D non-LTE formation of Ba ii lines in the solar atmosphere
• A NLTE line formation for neutral and singly-ionised titanium in model atmospheres of the reference A-K stars
• Influence of inelastic collisions with hydrogen atoms on the non-LTE modelling of Ca I and Ca II lines in late-type stars
• The Gaia-ESO survey: 3D NLTE abundances in the open cluster NGC 2420 suggest atomic diffusion and turbulent mixing at the origin of chemical abundance variations
• The chemical composition of globular clusters in the Local Group
• The Gaia-ESO survey: Hydrogen lines in red giants directly trace stellar mass
• Probing 3D and NLTE models using APOGEE observations of globular cluster stars
• NLTE 1.5D Modeling of Red Giant Stars

Cited by in corpus (31)

• PySME -- Spectroscopy Made Easier
• Constraining atmospheric parameters and surface magnetic fields with $\text{ZeeTurbo}$: an application to SPIRou spectra
• Observational constraints on the origin of the elements. VII. NLTE analysis of Y II lines in spectra of cool stars and implications for Y as a Galactic chemical clock
• Korg: a modern 1D LTE spectral synthesis package
• Observational constraints on the origin of the elements. V. Non-LTE abundance ratios of [Ni/Fe] in Galactic stars and enrichment by sub-Chandrasekhar mass SNe
• NLTE analysis of the methylidyne radical (CH) molecular lines in metal-poor stellar atmospheres
• The GALAH survey: Tracing the Milky Way's formation and evolution through RR Lyrae stars
• 1D non-LTE corrections for chemical abundance analyses of very metal-poor stars
• Titans metal-poor reference stars II. Red giants and CEMP stars
• Observational constraints on the origin of the elements. IX. 3D NLTE abundances of metals in the context of Galactic Chemical Evolution Models and 4MOST
• Evidence of Gaia Enceladus experiencing at least two passages around the Milky Way
• NLTE abundances of Eu for a sample of metal-poor stars in the Galactic Halo and Metal-poor Disk with 1D and <3D> models
• LOTUS: A (non-)LTE Optimization Tool for Uniform derivation of Stellar atmospheric parameters
• Discovery of a pair of very metal-poor stars enriched in neutron-capture elements: The proto-disk r-II star BPS CS 29529-0089 and the Gaia-Sausage-Enceladus r-I star TYC 9219-2422-1
• Stellar Population Astrophysics (SPA) with the TNG: NLTE atmospheric parameters and abundances of giant stars in 33 Open Clusters
• The GALAH survey: Improving chemical abundances using star clusters
• Performance of the Stellar Abundances and atmospheric Parameters Pipeline adapted for M dwarfs I. Atmospheric parameters from the spectroscopic module
• M3DIS -- A grid of 3D radiation-hydrodynamics stellar atmosphere models for stellar surveys. II. Carbon-enhanced metal-poor stars
• Rare Find: Discovery and chemo-dynamical properties of two s-process enhanced RR Lyrae stars
• Oxygen Isotope Ratios in Hydrogen-Deficient Carbon Stars: A Correlation with Effective Temperature and Implications for White Dwarf Merger Outcomes
• Abundance analysis of benchmark M dwarfs
• Chemical composition of planetary hosts: II. Abundances of neutron-capture elements
• The metal-poorest tail of the Galactic halo: hypothesis on its origin from precise spectral analysis
• Exploring the History of Stellar Mergers with Chemistry: Examining the Origins of Massive $\alpha$-Enriched Stars using Carbon Isotope Ratios
• Th/Eu abundance ratio of red giants in the Kepler Field
• Calibration of the [C/N] and [Y/Mg] chemical clocks with asteroseismic ages from the TESS space mission
• Disentangling Milky Way halo populations at low metallicities using [Al/Fe]
• Investigating non-LTE abundances of Neodymium (Nd) in metal-poor FGK stars
• Quantifying Element Importance for Mass Recovery from Population III Supernova Yield Fits
• Observational constraints on the origin of the elements. X. Combining NLTE and machine learning for chemical diagnostics of 4 million stars in the 4MIDABLE-HR survey
• A method to derive self-consistent NLTE astrophysical parameters for 4 million high-resolution 4MOST stellar spectra in half a day with invertible neural networks