3D spectral synthesis for Bernd Freytag's CO⁵BOLD models of supergiant stars

Synthetic spectrum (LTE with scattering) for model st35gm04n33 integrated over the upper XY face (Z=117).

Movie that shows model st35gm04n33 from one face going in monochromatic light (in log scale) going through the spectrum.

The very first time series for model st35gm04n33 consisting of three time steps.

The longest computed time series to date (different model).

Different presentation of spectral time series.

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The A-star puzzle

Many previous attempts to reproduce line asymmetry in A-stars failed: the hydrodynamical models would predict steeper blue wing (like on the Sun) while the observations show the opposite. The new models computed with CO⁵BOLD code in "box-in-star" framework and an accurate disk integration using several rays qualitatively match the observations. The effects on different spectral lines should be further investigated.

The at80g40n20 surface brightness in various wavelengths for one small segment of the stellar surface.

Points used in disk integration of the flux spectra.

Specific intensity profiles for various points on the stellar disk marked on the figure above (upper group of curves). Disk integrated profile (green line) compared to the Solar spectrum (black line). Note the opposite direction of line asymmetry in A-star and in the Sun (bottom two curves).

Comparison with the observations using 1D static models (upper panel) and 3D dynamic models (bottom panel). 1D models do not come anywhere near the observations.

SME tar file The official release of the SME is here. You can download it now following the link on the left. We do not exclude some bugs and back-compatibility issues but together we will prevail.

Here is the HARPSpol HD209100 data