the 3d morphology of vy canis majoris: kinematics, polarimetry, …€¦ · kinematics,...

Minnesota IR Group

The 3D Morphology of VY Canis Majoris:Kinematics, Polarimetry, and the Line-of-

Sight Distribution of the Ejecta

Terry Jay Jones, Roberta M. Humphreys, and L. Andrew Helton – University of Minnesota

Changfeng Gui and Xiang Huang –University of Connectitcut

Minnesota IR GroupRichards et al. 1998 (Merlin)

Minnesota IR Group

SiO J = 1 – 0

Shinnaga et al. 2003

658nm HST image

Minnesota IR Group

High resolution imaging with HST/WFPC2 in 2 epochs

High resolution spectroscopy (Keck)

Polarimetry with HST/ACS/HRC

Radial Velocities + Proper Motion = Total Motion

Polarimetry = Independent Placement in 3D

The Data Set

Minnesota IR Group

Proper motions of selected clumps, arcs and features in the reflection nebulosity surrounding VYCMa

Minnesota IR Group

NW Arc500yrs

Arc 1800yrs

Arc 2 – 460yrs

SW Knots250yrs

S Knots160yrs

S Arc480yrs

Minnesota IR Group

Minnesota IR Group

Total Intensity Photometric Color Fractional Polarization

Note: Most features in the intensity map are also distinctive in the fractional polarization map = distinct features

Minnesota IR Group

NW Arc

Arc 1Arc 2

S Arc

Fractional Polarization

Minnesota IR Group

Conclusions

• The arcs and knots appear to be separate geometric objects.

• They do not display any clear association with a simple bipolar outflow geometry.

• There is good agreement between the 3D geometry derived from two independent techniques.

• Some sort of magnetic phenomena near the star?