Three-dimensional hydrodynamical CO5BOLD model atmospheres of red giant stars VI. First chromosphere model of a late-type giant

@article{Wedemeyer2017ThreedimensionalHC,
  title={Three-dimensional hydrodynamical CO5BOLD model atmospheres of red giant stars VI. First chromosphere model of a late-type giant},
  author={Sven Wedemeyer and Arūnas Ku{\vc}inskas and Jonas Klevas and Hans-G. Ludwig},
  journal={arXiv: Solar and Stellar Astrophysics},
  year={2017}
}
Although observational data unequivocally point out to the presence of chromospheres in red giant stars, no attempts have been made so far to model them using 3D hydrodynamical model atmospheres. We therefore compute an exploratory 3D hydrodynamical model atmosphere for a cool red giant in order to study the dynamical and thermodynamic properties of its chromosphere, as well as the influence of the chromosphere on its observable properties. 3D radiation hydrodynamics simulations are carried out… 

Figures from this paper

Spatially resolving the thermally inhomogeneous outer atmosphere of the red giant Arcturus in the 2.3 μm CO lines

Aim. The outer atmosphere of K giants shows thermally inhomogeneous structures consisting of the hot chromospheric gas and the cool molecular gas. We present spectro-interferometric observations of

Using the CIFIST grid of CO5BOLD 3D model atmospheres to study the effects of stellar granulation on photometric colours. I. Grids of 3D corrections in the UBVRI, 2MASS, Hipparcos, Gaia, and SDSS systems

The atmospheres of cool stars are temporally and spatially inhomogeneous due to the effects of convection.The influence of this inhomogeneity, referred to as granulation, on colours has never been

Constraining Stellar Parameters and Atmospheric Dynamics of the Carbon AGB star V Oph

Molecules and dust produced by the atmospheres of cool evolved stars contribute to a significant amount of the total material found in the interstellar medium. To understand the mechanism behind the

Mass loss of stars on the asymptotic giant branch

As low- and intermediate-mass stars reach the asymptotic giant branch (AGB), they have developed into intriguing and complex objects that are major players in the cosmic gas/dust cycle. At this

Multiple populations within globular clusters in Early-type galaxies Exploring their effect on stellar initial mass function estimates

It is now well-established that most (if not all) ancient globular clusters host multiple popula- tions, that are characterised by distinct chemical features such as helium abundance variations along

Internal Gravity Waves in the Magnetized Solar Atmosphere. II. Energy Transport

In this second paper of the series on internal gravity waves (IGWs), we present a study of the generation and propagation of IGWs in a model solar atmosphere with diverse magnetic conditions. A

Stellar Activity–Phenomenology and General Principles

  • J. Linsky
  • Physics, Geology
    Lecture Notes in Physics
  • 2019
In this chapter, the different types of stellar activity whose underlying cause is heating and particle acceleration by magnetic processes are described.

References

SHOWING 1-10 OF 43 REFERENCES

Modelling chromospheric line profiles as diagnostics of velocity fields in ω Centauri red giant stars

Context. Mass loss of ∼0.1−0.3 Mfrom Population II red giant stars (RGB) is a requirement of stellar evolution theory in order to account for several observational evidences in globular clusters.

A grid of MARCS model atmospheres for late-type stars. I. Methods and general properties

Context. In analyses of stellar spectra and colours, and for the analysis of integrated light from galaxies, a homogeneous grid of model atmospheres of late-type stars and corresponding flux spectra

CHROMOSPHERIC MODELS AND THE OXYGEN ABUNDANCE IN GIANT STARS

Realistic stellar atmospheric models of two typical metal-poor giant stars in Omega Centauri, which include a chromosphere (CHR), influence the formation of optical lines of O i: the forbidden lines

Goddard High-Resolution Spectrograph Observations of Cool Low-Gravity Stars. IV. A Comparison of the K5 III stars α Tauri and γ Draconis

The Goddard High-Resolution Spectrograph (GHRS) has observed the K5 III star α Tau in the 2330 Å region on three separate occasions. These spectra show marked changes with time, with the UV continuum

Structure of the outer layers of cool standard stars

Context. Among late-type red giants, an interesting change occurs in the structure of the outer atmospheric layers as one moves to later spectral types in the Hertzsprung-Russell diagram: a

Solar Chemical Abundances Determined with a CO5BOLD 3D Model Atmosphere

In the last decade, the photospheric solar metallicity as determined from spectroscopy experienced a remarkable downward revision. Part of this effect can be attributed to an improvement of atomic

Structure of the solar chromosphere. III. Models of the EUV brightness components of the quiet sun

Skylab observations of the quiet Sun in the EUV wavelength range 40--140 nm show the inhomogeneous structure of the chromosphere. We use these observations to determine separate chromospheric models

MASS OUTFLOW AND CHROMOSPHERIC ACTIVITY OF RED GIANT STARS IN GLOBULAR CLUSTERS. I. M15

High-resolution spectra of 110 selected red giant stars in the globular cluster M15 (NGC 7078) were obtained with Hectochelle at the MMT telescope in 2005 May, 2006 May, and 2006 October. Echelle

The outer atmosphere of α Tau – III. Inhomogeneities deduced from cold CO fluorescence

Ultraviolet spectra of α Tau obtained with the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope show clusters of CO emission lines which are excited by the O i (uv2)