High Resolution VLA Continuum and Radio Recombination Line Emission in W49A
Abstract
Radio continuum observations show that some Galactic UC HII regions can vary significantly in radio flux density on time scales of 10-20 years. In 2018, we reported such variations in W49A at 3.6 cm with the B-configuration at ~0.8″ resolution. W49A/G2 decreased by 20% in peak intensity (from 71 ± 4 mJy/beam to 57 ± 3 mJy/beam), and 40% in integrated flux (from 0.109 ± 0.011 Jy to 0.067 ± 0.007 Jy) between 1994 and 2015. In this poster, we present new high-sensitivity A-configuration 7 mm (~0.05″ resolution) and 3.6 cm (~0.15″ resolution) radio continuum images of the W49A region, and identify a number of previously unresolved sources and morphologies at 3.6 cm. In addition, we present new high-resolution radio recombination line (RRL) data at 7 mm and 3.6 cm associated with W49A/G2 and other sources in the region.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23530802D