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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We investigate the importance of the pseudo-continuum bound-free opacity fromhydrogen atoms in the atmospheres of cool white dwarfs. This source ofabsorption, when calculated by the occupation probability formalism applied inthe modeling of white dwarf atmospheres with $T_{\rm eff}\rm <17000 K$,dominates all other sources of opacity at optical wavelengths. This isunrealistic and not observed. On the other hand, a significant flux suppressionin the blue part of the spectra of cool white dwarfs has been reported, andmainly interpreted as a result of the pseudo-continuum absorption from atomichydrogen. We investigate this problem by proposing a new, more realisticapproach to calculating this source of opacity. We show that this absorption isorders of magnitude smaller than that predicted by current methods. Therefore,we rule out the pseudo-continuum opacity as a source of the flux deficiencyobserved in the spectra of cool white dwarfs.Comment: 11 pages, 5 gigures, accepted for publication in the Astrophysical  Journa

The Pseudocontinuum Bound‐Free Opacity of Hydrogen and Its Importance in Cool White Dwarf Atmospheres