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 the radio/X-ray correlation in Cyg X-3. It has been known that thesoft and hard X-ray fluxes in the hard spectral state are correlated positivelyand negatively, respectively, with the radio flux. We show that this impliesthat the observed $\sim$1--100 keV flux (which is a fair approximation to thebolometric flux) is completely uncorrelated with the radio flux. We can recovera positive correlation (seen in other sources and expected theoretically) ifthe soft X-rays are strongly absorbed by a local medium. Then, however, theintrinsic X-ray spectrum of Cyg X-3 in its hard state becomes relatively soft,similar to that of an intermediate spectral state of black-hole binaries, butnot to their true hard state. We also find the radio spectra in the hard stateof Cyg X-3 are hard on average, and the flux distributions of the radioemission and soft X-rays can be described by sums of two log-normal functions.We compare Cyg X-3 with other X-ray binaries using colour-colour,colour-Eddington ratio and Eddington ratio-radio flux diagrams. We find Cyg X-3to be spectrally most similar to GRS 1915+105, except that Cyg X-3 issubstantially more radio loud, which appears to be due to its jet emissionenhanced by interaction with the powerful stellar wind from the Wolf-Rayetdonor.

The radio/X-ray correlation in Cyg X-3 and the nature of its hard spectral state