Detection of reactive ions in the ultracompact H II regions Monoceros R2 and G29.96-0.02
We report the first detection of the reactive ions CO+ and HOC+ toward ultracompact (UC) H II regions, particularly in Mon R2 and G29.96-0.02. We have observed two positions in Mon R2, namely, the peak of the UC H II region and the surrounding high-density molecular cloud. CO + and HOC+ were detecte...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2003 |
| País: | España |
| Institución: | Universidad Europea (UEM) |
| Repositorio: | ABACUS. Repositorio de Producción Científica |
| Idioma: | inglés |
| OAI Identifier: | oai:abacus.universidadeuropea.com:11268/5683 |
| Acceso en línea: | http://hdl.handle.net/11268/5683 |
| Access Level: | acceso abierto |
| Palabra clave: | Galaxias Estrellas Astrofísica Galaxia |
| Sumario: | We report the first detection of the reactive ions CO+ and HOC+ toward ultracompact (UC) H II regions, particularly in Mon R2 and G29.96-0.02. We have observed two positions in Mon R2, namely, the peak of the UC H II region and the surrounding high-density molecular cloud. CO + and HOC+ were detected at the UC H II region but not at the molecular cloud, as expected if both ions arise in the photodissociation region (PDR) surrounding the UC H II region. The measured column densities are on the order of 1011 cm-2 in both sources, which yields a strikingly low [HCO+]/[HOC+] abundance ratio of 460 in Mon R2. These values are similar to those found in some other well-known PDRs, like NGC 7023 and the Orion bar. We briefly discuss the chemical implications of these results. |
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