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

The model atmosphere programs FASTWIND and CMFGEN are both elegantly designedto perform non-LTE analyses of the spectra of hot massive stars, and includesphericity and mass-loss. The two codes differ primarily in their approachtowards line blanketing, with CMFGEN treating all of the lines in the co-movingframe and FASTWIND taking an approximate approach which speeds up executiontimes considerably. Although both have been extensively used to model thespectra of O-type stars, no studies have used the codes to independently modelthe same spectra of the same stars and compare the derived physical properties.We perform this task on ten O-type stars in the Magellanic Clouds. For thelate-type O supergiants, both CMFGEN and FASTWIND have trouble fitting some ofthe He I lines, and we discuss causes and cures. We find that there is nodifference in the average effective temperatures found by the two codes for thestars in our sample, although the dispersion is large, due primarily to thevarious difficulties each code has with He I. The surface gravities determinedusing FASTWIND are systematically lower by 0.12 dex compared to CMFGEN, aresult we attribute to the better treatment of electron scattering by CMFGEN.This has implications for the interpretation of the origin of the so-calledmass discrepancy, as the masses derived by FASTWIND are on average lower thaninferred from stellar evolutionary models, while those found by CMFGEN are inbetter agreement.

A Bake-Off Between CMFGEN and FASTWIND: Modeling the Physical Properties of SMC and LMC O-type Stars