相关论文: Calibrating the {\alpha} parameter of convective e…
Convective boundary mixing (CBM) is ubiquitous in stellar evolution. It is a necessary ingredient in the models in order to match observational constraints from clusters, binaries and single stars alike. We compute `effective overshoot'…
One of the key ingredients in establishing the relation between input signal and output flux from a spectrometer is accurate determination of the spectrophotometric calibration. In the case of spectrometers onboard satellites, the accuracy…
I describe recent progress in terms of 3D hydrodynamical model atmospheres and 3D line formation and their applications to stellar abundance analyses of late-type stars. Such 3D studies remove the free parameters inherent in classical 1D…
The best way to check the validity of our theories (models) is by direct comparison with the experiment (observations). In this study, we address the numerical inaccuracies intrinsic to the process of comparing theory and observations. To…
The B/C ratio is used in cosmic-ray physics to constrain the transport parameters. However, from the same set of data, the various published values show a puzzling large scatter of these parameters. We investigate the impact of using…
Many phenomenologically successful cosmological galaxy formation simulations employ kinetic winds to model galactic outflows, a crucial ingredient in obtaining predictions that agree with various observations. Yet systematic studies of how…
This article investigates the problem of estimating stellar atmospheric parameters from spectra. Feature extraction is a key procedure in estimating stellar parameters automatically. We propose a scheme for spectral feature extraction and…
A model is developed for the transport of heat and solute in a system of double-diffusive layers under astrophysical conditions (viscosity and solute diffusivity low compared with the thermal diffusivity). The process of formation of the…
As part of a larger program aimed at better quantifying the uncertainties in stellar computations, we attempt to calibrate the extent of convective overshooting in low to intermediate mass stars by means of eclipsing binary systems. We…
The fine structure constant, $\alpha$, sets the strength of the electromagnetic force. The Standard Model of particle physics provides no explanation for its value, which could potentially vary. The wavelengths of stellar absorption lines…
Multidimensional hydrodynamic simulations of shell convection in massive stars suggest the development of aspherical perturbations that may be amplified during iron core-collapse. These perturbations have a crucial and qualitative impact on…
In this work we have used 3D hydrodynamical (CO5BOLD) and 1D hydrostatic (LHD) stellar atmosphere models to study the importance of convection and horizontal temperature inhomogeneities in stellar abundance work related to late-type giants.…
A detailed spectroscopic study of the ISO-SWS data of the red giant Alpha Tau is presented, which enables not only the accurate determination of the stellar parameters of Alpha Tau, but also serves as a critical review of the ISO-SWS…
We perform spectral fitting for a set of O-type stars based on self-consistent wind solutions, which provide mass-loss rate and velocity profiles directly derived from the initial stellar parameters. The great advantage of this…
We investigate early galaxy evolution by modeling self-consistently their radially-resolved evolution of gas, stars, heavy elements, and dust content. Our model successfully reproduces various observed properties of JWST-identified galaxies…
Relations between temperature, T, and optical depth, tau, are often used for describing the photospheric transition from optically thick to optically thin in stellar structure models. We show that this is well justified, but also that…
Context. Departures from local thermodynamic equilibrium (LTE) distort the calcium abundance derived from stellar spectra in various ways, depending on the lines used and the stellar atmospheric parameters. The collection of atomic data…
The accurate measurement of stellar masses over a wide range of galaxy properties is essential for better constraining models of galaxy evolution. Emission line galaxies (ELGs) tend to have better redshift estimates than continuum-selected…
Oxygen is a powerful tracer element of Galactic chemical evolution. Unfortunately, only a few oxygen lines are available in the ultraviolet-infrared stellar spectra for the reliable determination of its abundance. Moreover, oxygen…
Numerical 3D radiative (M)HD simulations of solar convection are used to understand the physical properties of the solar photosphere. To validate this approach, it is important to check that no excessive thermodynamic fluctuations arise as…