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 study a possibility of detection of circumstellar absorption lines of Na ID$_{1,2}$ and Ca II H,K in spectra of type IIP supernovae at the photosphericepoch. The modelling shows that the circumstellar lines of Na I doublet willnot be seen in type IIP supernovae for moderate wind density, e.g.,characteristic of SN 1999em, whereas rather pronounced Ca II lines with P Cygniprofile should be detectable. A similar model is used to describe Na I and CaII circumstellar lines seen in SN 1998S, type IIL with a dense wind. We showthat line intensities in this supernova are reproduced, if one assumes anultraviolet excess, which is caused primarily by the comptonization ofsupernova radiation in the shock wave.

Circumstellar Na I and Ca II lines in type IIP supernovae and SN 1998S