W49A - Bipolar Morphology
Description
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).
Creator
Legacy Astronomical Images
Rights
NRAO/AUI/NSF does not hold full copyright for this image. Contact the archivist for details.
Type
Legacy Astronomical Image
Object Name
W49A
Investigators
Chris De Pree, Miller Goss, Jack Welch, David Wilner
Telescope
Very Large Array (VLA)
Observation Date
2001-00-00
Type of Observation
continuum
Center of Image
RA 19:10:15.650, Dec: 9:6:5.500 (J2000)
Field of View
0.002778 x 0.002778 degrees
Notes
Contact the archivist for a high resolution tif of this image.
Series
Galactic Sources Series
Unit
Star Forming Regions Unit
Citation
Legacy Astronomical Images, “W49A - Bipolar Morphology,” NRAO/AUI Archives, accessed August 17, 2024, https://www.nrao.edu/archives/items/show/33487.