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 Atacama Large Millimeter/submillimeter Array (ALMA) line andcontinuum observations at 1.2mm with ~0.3" resolution that uncover aKeplerian-like disk around the forming O-type star AFGL 4176. The continuumemission from the disk at 1.21 mm (source mm1) has a deconvolved size of870+/-110 AU x 330+/-300 AU and arises from a structure ~8 M_sun in mass,calculated assuming a dust temperature of 190 K. The first-moment maps,pixel-to-pixel line modeling, assuming local thermodynamic equilibrium (LTE),and position-velocity diagrams of the CH3CN J=13-12 K-line emission all show avelocity gradient along the major axis of the source, coupled with an increasein velocity at small radii, consistent with Keplerian-like rotation. The LTEline modeling shows that where CH3CN J=13-12 is excited, the temperatures inthe disk range from ~70 to at least 300 K and that the H2 column density peaksat 2.8x10^24 cm^-2. In addition, we present Atacama Pathfinder Experiment(APEX) 12CO observations which show a large-scale outflow from AFGL 4176perpendicular to the major axis of mm1, supporting the disk interpretation.Finally, we present a radiative transfer model of a Keplerian disk surroundingan O7 star, with a disk mass and radius of 12 M_sun and 2000 AU, thatreproduces the line and continuum data, further supporting our conclusion thatour observations have uncovered a Keplerian disk around an O-type star.

A Keplerian-like disk around the forming O-type star AFGL 4176