Ultracompact H II Regions with Extended Emission: The Complete View
| Autor: | de la Fuente, Eduardo, Porras, Alicia, Trinidad, Miguel A., Kurtz, Stanley E., Kemp, Simon N., Tafoya, Daniel, Franco, José, Rodríguez-Rico, Carlos |
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| Rok vydání: | 2019 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stz3482 |
| Popis: | In this paper we present the results of a morphological study performed on a sample of 28 ultracompact \hiirs~located near extended free-free emission, using radio continuum observations at 3.6~cm with the C and D VLA~configurations, with the aim of determining a direct connection between them. By using previously published observations in B and D VLA~configurations, we compiled a final catalogue of 21 ultracompact \hiirs ~directly connected with the surrounding extended emission. The observed morphology of most of the ultracompact \hiirs~in radio continuum emission is irregular (single or multi-peaked sources) and resembles a classical bubble structure in the Galactic plane with well-defined cometary arcs. Radio continuum images superimposed on colour composite \textit{Spitzer} images reinforce the assignations of direct connection by the spatial coincidence between the ultracompact components and regions of saturated 24~\micron~emission. We also find that the presence of extended emission may be crucial to understand the observed infrared-excess because an underestimation of ionizing Lyman photons was considered in previous works. Comment: 21 pages, 4 figures, to be Published on Monthly Notices of the Royal Astronomical Society (Accepted: December, 18, 2019) |
| Databáze: | arXiv |
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