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 results of an intensive spectroscopic campaign in the opticalwaveband revealing that Cyg OB2 #8A is an O6 + O5.5 binary system with a periodof about 21.9 d. Cyg OB2 #8A is a bright X-ray source, as well as a non-thermalradio emitter. We discuss the binarity of this star in the framework of acampaign devoted to the study of non-thermal emitters, from the radio wavebandto gamma-rays. In this context, we attribute the non-thermal radio emissionfrom this star to a population of relativistic electrons, accelerated by theshock of the wind-wind collision. These relativistic electrons could also beresponsible for a putative gamma-ray emission through inverse Comptonscattering of photospheric UV photons, thus contributing to the yetunidentified EGRET source 3EG J2033+4118.Comment: 8 pages, 4 figures, conference on "The Multiwavelength Approach to  Gamma-Ray Sources", to appear in Ap&S

On the Multiplicity of the O-Star Cyg OB2 #8a and its Contribution to the γ-ray Source 3EG J2033+4118