CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

EXTERNALLY HEATED PROTOSTELLAR CORES in the OPHIUCHUS STAR-FORMING REGION

Johan E. Lindberg ; Steven B. Charnley ; Jes K. Jørgensen ; Martin A. Cordiner ; Per Bjerkeli (Institutionen för rymd- och geovetenskap, Onsala rymdobservatorium)
Astrophysical Journal (0004637X). Vol. 835 (2017), 1, p. 3.
[Artikel, refereegranskad vetenskaplig]

We present APEX 218 GHz observations of molecular emission in a complete sample of embedded protostars in the Ophiuchus star-forming region. To study the physical properties of the cores, we calculate H2CO and c-C3H2 rotational temperatures, both of which are good tracers of the kinetic temperature of the molecular gas. We find that the H2CO temperatures range between 16 K and 124 K, with the highest H2CO temperatures toward the hot corino source IRAS 16293-2422 (69-124 K) and the sources in the ? Oph A cloud (23-49 K) located close to the luminous Herbig Be star S1, which externally irradiates the ? Oph A cores. On the other hand, the c-C3H2 rotational temperature is consistently low (7-17 K) in all sources. Our results indicate that the c-C3H2 emission is primarily tracing more shielded parts of the envelope whereas the H2CO emission (at the angular scale of the APEX beam; 3600 au in Ophiuchus) mainly traces the outer irradiated envelopes, apart from in IRAS 16293-2422, where the hot corino emission dominates. In some sources, a secondary velocity component is also seen, possibly tracing the molecular outflow.

Nyckelord: astrochemistry; ISM: individual objects (Ophiuchus); ISM: molecules; radiative transfer; stars: formation



Denna post skapades 2017-03-16. Senast ändrad 2017-03-16.
CPL Pubid: 248579

 

Läs direkt!


Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för rymd- och geovetenskap, Onsala rymdobservatorium (2010-2017)

Ämnesområden

Fysik

Chalmers infrastruktur