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 paper investigates the milli-arcsecond scale structure of the present-daymass-loss of the post-Red Supergiant IRC+10420. We use three telescopes of theVLT Interferometer in combination with the AMBER near-infrared beam combiner tomeasure spectrally dispersed correlated fluxes in the K-band around the Brgamma transition. The resulting visibilities are compared to the predictedvisibilities of emission structures with various simple models in order toinfer the size of the observed emission region. The Br gamma line is resolvedby VLTI+AMBER on all three baselines, with the maximum projected baselineextending 69 meter and a P.A. ranging between 10 and 30 degrees. A differentialphase between line and continuum is detected on the longest baseline. The Brgamma emission region is found to have a diameter of 3.3 milli-arcseconds(FWHM), when compared to a Gaussian intensity distribution. A uniform disk anda ring-like intensity distribution do not fit the line visibilities. Comparingthe AMBER equivalent width of Br gamma with measurements from various epochs,we find that the stellar photosphere contributes about 60% of the totalcontinuum light at 2.2 micron. The remaining 40% continuum emission is found onscales larger than the 66mas AMBER field of view. Using simple arguments, andassuming optically thick line emission, we find that the line emitting regionis elongated. We briefly discuss the possibilities whether such a structure isdue to a bi-polar flow or a circumstellar disk. (Abridged).

Resolving the ionized wind of the post-Red Supergiant IRC +10 420 with VLTI/AMBER