English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present the first grid of mean three-dimensional (3D) spectra forpure-hydrogen (DA) white dwarfs based on 3D model atmospheres. We use CO5BOLDradiation-hydrodynamics 3D simulations instead of the mixing-length theory forthe treatment of convection. The simulations cover the effective temperaturerange of 6000 < Teff (K) < 15,000 and the surface gravity range of 7 < log g <9 where the large majority of DAs with a convective atmosphere are located. Werely on horizontally averaged 3D structures (over constant Rosseland opticaldepth) to compute <3D> spectra. It is demonstrated that our <3D> spectra can besmoothly connected to their 1D counterparts at higher and lower Teff where the3D effects are small. Analytical functions are provided in order to convertspectroscopically determined 1D effective temperatures and surface gravities to3D atmospheric parameters. We apply our improved models to well studiedspectroscopic data sets from the Sloan Digital Sky Survey and the White DwarfCatalog. We confirm that the so-called high-log g problem is not present whenemploying <3D> spectra and that the issue was caused by inaccuracies in the 1Dmixing-length approach. The white dwarfs with a radiative and a convectiveatmosphere have derived mean masses that are the same within ~0.01 Msun, inmuch better agreement with our understanding of stellar evolution. Furthermore,the 3D atmospheric parameters are in better agreement with independent Teff andlog g values from photometric and parallax measurements.

Spectroscopic analysis of DA white dwarfs with 3D model atmospheres