EXPANDED VERY LARGE ARRAY OBSERVATIONS OF THE NEBULA AROUND G79.29+0.46
- INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania (Italy)
- Department of Physics and Astronomy, Universita di Catania and INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania (Italy)
- Spitzer Science Center, California Institute of Technology, Mail Code 314-6, Pasadena, CA 91125 (United States)
We have observed the radio nebula surrounding the Galactic luminous blue variable candidate G79.29+0.46 with the Expanded Very Large Array (EVLA) at 6 cm. These new radio observations allow a morphological comparison between the radio emission, which traces the ionized gas component, and the mid-IR emission, a tracer of the dust component. The InfraRed Array Camera (8 {mu}m) and the Multiband Imaging Photometer for Spitzer (24 {mu}m and 70 {mu}m) images have been reprocessed and compared with the EVLA map. We confirm the presence of a second shell at 24 {mu}m and also provide evidence for its detection at 70 {mu}m. The differences between the spatial morphology of the radio and mid-IR maps indicate the existence of two dust populations, the cooler one emitting mostly at longer wavelengths. Analysis of the two dusty, nested shells have provided us with an estimate of the characteristic timescales for shell ejection, providing important constraints for stellar evolutionary models. Finer details of the ionized gas distribution can be appreciated thanks to the improved quality of the new 6 cm image, most notably the highly structured texture of the nebula. Evidence of interaction between the nebula and the surrounding interstellar medium can be seen in the radio map, including brighter features that delineate regions where the shell structure is locally modified. In particular, the brighter filaments in the southwest region appear to frame the shocked southwestern clump reported from CO observations.
- OSTI ID:
- 21565444
- Journal Information:
- Astrophysical Journal Letters, Vol. 739, Issue 1; Other Information: DOI: 10.1088/2041-8205/739/1/L11; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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