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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Deeply embedded protostars are actively fed from their surrounding envelopesthrough their protostellar disk. The physical structure of such early disksmight be different from that of more evolved sources due to the activeaccretion. We present 1.3 and 3\,mm ALMA continuum observations at resolutionsof 6.5\,au and 12\,au respectively, towards the Class 0 source IRAS 16293-2422B. The resolved brightness temperatures appear remarkably high, with $T_{\rm b}>$ 100\,K within $\sim$30\,au and $T_{\rm b}$ peak over 400\,K at 3\,mm. Bothwavelengths show a lopsided emission with a spectral index reaching values lessthan 2 in the central $\sim$ 20\,au region. We compare these observations witha series of radiative transfer calculations and synthetic observations ofmagnetohydrodynamic and radiation hydrodynamic protostellar disk models formedafter the collapse of a dense core. Based on our results, we argue that the gaskinematics within the disk may play a more significant role in heating the diskthan the protostellar radiation. In particular, our radiation hydrodynamicsimulation of disk formation, including heating sources associated withgravitational instabilities, is able to generate the temperatures necessary toexplain the high fluxes observed in IRAS 16293B. Besides, the low spectralindex values are naturally reproduced by the high optical depth and high innertemperatures of the protostellar disk models. The high temperatures in IRAS16293B imply that volatile species are mostly in the gas phase, suggesting thata self-gravitating disk could be at the origin of a hot corino.

The young protostellar disk in IRAS16293-2422 B is hot and shows signatures of gravitational instability