W49A - Bipolar Morphology

The bipolar W49A/A region as imaged with the VLA at (a) 3.6 cm, (b) 6 cm, and (c) 7 mm. This comparison indicates the importance of multifrequency, subarcsecond resolution imaging in determining the nature of UC HII regions like W49A/A. Source A has a distinctly bipolar morphology at the resolution of the 3.6 cm observations (beam =0.8"). The high-resolution 6 cm VLA image (beam =0.4"; Welch et al. 1987) indicates that the bipolar lobes are strongly edge-brightened. Finally a high-resolution (beam =0.04") 7 mm view of the source indicates that the central peak is itself an edge-brightened shell , having a center-to-edge brightness ratio consistent with an inclined ring of emission (see De Pree et al. 2000).

Legacy Astronomical Images

NRAO/AUI/NSF does not hold full copyright for this image. Contact the archivist for details.

Legacy Astronomical Image

W49A

Chris De Pree, Miller Goss, Jack Welch, David Wilner

Very Large Array (VLA)

2001-00-00

continuum

RA 19:10:15.650, Dec: 9:6:5.500 (J2000)

0.002778 x 0.002778 degrees

Contact the archivist for a high resolution tif of this image.

Galactic Sources Series

Star Forming Regions Unit