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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We investigate at a high angular resolution the spatial and kinematicstructure of the S255IR high mass star-forming region, which demonstratedrecently the first disk-mediated accretion burst in the massive young stellarobject. The observations were performed with ALMA in Band 7 at an angularresolution $ \sim 0.1^{\prime\prime}$, which corresponds to $ \sim 180 $ AU.The 0.9 mm continuum, C$^{34}$S(7-6) and CCH $N=4-3$ data show a presence ofvery narrow ($ \sim 1000 $ AU), very dense ($n\sim 10^7$ cm$^{-3}$) and warmfilamentary structures in this area. At least some of them represent apparentlydense walls around the high velocity molecular outflow with a wide openingangle from the S255IR-SMA1 core, which is associated with the NIRS3 YSO. Thiswide-angle outflow surrounds a narrow jet. At the ends of the molecular outflowthere are shocks, traced in the SiO(8-7) emission. The SiO abundance there isenhanced by at least 3 orders of magnitude. The CO(3-2) and SiO(8-7) data showa collimated and extended high velocity outflow from another dense core in thisarea, SMA2. The outflow is bent and consists of a chain of knots, which mayindicate periodic ejections possibly arising from a binary system consisting oflow or intermediate mass protostars. The C$^{34}$S emission shows evidence ofrotation of the parent core. Finally, we detected two new low mass compactcores in this area (designated as SMM1 and SMM2), which may representprestellar objects.

Dense Cores, Filaments and Outflows in the S255IR Region of High Mass Star Formation