 |
|
| EPoS Contribution |
|
A Keplerian-like disk around the forming O-type star AFGL 4176
Katharine Johnston U Leeds, Leeds, UK | |
| I will present our ALMA line and continuum observations at 1.2mm with ~0.3" resolution that uncover a Keplerian-like disk around the forming O-type star AFGL 4176. The first-moment maps, pixel-to-pixel line modelling and position-velocity diagrams of the CH3CN J = 13-12 K-line emission all show a velocity gradient along the major axis of the source, coupled with an increase in velocity at small radii, consistent with Keplerian-like rotation. I will also present APEX 12CO observations that show a large-scale outflow from AFGL4176 perpendicular to the major axis of mm1, supporting the disk interpretation. Finally, I will present our radiative transfer modelling of the ALMA data, showing that a Keplerian disk surrounding an O7 star, with a disk mass and radius of 12 Msol and 2000 AU that reproduces the line and continuum data, further supporting our conclusion that our observations have uncovered a Keplerian-like disk around an O-type star. | |
 | |
| Caption: First-moment map of the CH3CN J = 13-12, K = 3 emission from AFGL 4176 mm1 in colourscale. The contours show 1.2mm continuum emission (starting at 10sigma). The beam is shown in the bottom left corner. A gradient in velocity of the CH3CN line is clearly seen along the major axis of the continuum emission, exhibiting that expected from a Keplerian velocity field, where the peak velocities are seen either side of the continuum peak position (Figure adapted from Johnston et al. 2015). | |
| Collaborators: T. Robitaille, MPIA, DE H. Beuther, MPIA, DE H. Linz, MPIA, DE P. Boley, Ural Federal U, RU R. Kuiper, MPIA/Eberhard Karls U, DE E. Keto, Harvard-Smithsonian CfA, US M. Hoare, U Leeds, GB |
Key publication
Suggested Session: Massive Star Formation |