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/

Zendy Plus

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

Zendy Tools

Zendy Open

Some astrophysical observations of molecular hydrogen point to a broadeningof the velocity distribution for molecules at excited rotational levels. Thiseffect is observed in both Galactic and high redshift clouds. Analysis of H_2,HD, and CI absorption lines has revealed the broadening effect in theabsorption system of QSO 1232+082 (z_{abs}=2.33771). We analyze line broadeningmechanisms by considering in detail the transfer of ultraviolet radiation (inthe resonance lines of the Lyman and Werner H_2 molecular bands) for variousvelocity distributions at excited rotational levels. The mechanism we suggestincludes the saturation of the lines that populate excited rotational levels(radiative pumping) and manifests itself most clearly in the case ofdirectional radiation in the medium. Based on the calculated structure of amolecular hydrogen cloud in rotational level populations, we have considered anadditional mechanism that takes into account the presence of aphotodissociation region. Note that disregarding the broadening effects weinvestigated can lead to a significant systematic error when the data areprocessed.

Directional Radiation and Photodissociation Regions in Molecular Hydrogen Clouds