Star forming regions linked to RCW78 and the discovery of a new IR bubble

• Autores: Cappa, Cristina Elisabeth; Rubio, R.; Romero, Gisela Andrea; Duronea, Nicolas Urbano; Firpo, Verónica
• Año de publicación: 2013
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: STAR FORMATION; BUBBLES; MOLECULAR GAS
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

With the aim of investigating the presence of molecular and dust clumps linked to two star forming regions identified  in the expanding molecular envelope of the stellar wind bubble RCW78, we analyzed the distribution of the molecular gas and cold dust. To accomplish this study we performed dust continuum observations at 870 mu m  and 13CO(2-1) line observations with the APEX telescope, using LABOCA and SHeFI-1 instruments, respectively, and analyzed Herschel images at 70, 160, 250, 350, and 500 mu m.  
These observations allowed us to identify cold dust clumps linked to region B (named the Southern clump) and region C (clumps 1 and 2) and an elongated Filament. Molecular gas was clearly detected linked to the Southern clump and the Filament. The velocity of the molecular gas is compatible with the location of the dense gas in the expanding envelope of RCW78. We estimate  dust temperatures and total masses for the dust condensations from  the emissions at different wavelengths in the far-IR and from the molecular line using LTE and the virial theorem. Masses obtained through different methods agree within a factor of 2-6. CC-diagrams and SED analysis of young stellar objects confirmed the presence of intermediate and low mass YSOs in the dust regions, indicating that moderate star formation is present.  In particular, a cluster of IR sources was identified inside the Southern clump. The IRAC image at 8 mu m revealed the existence of an infrared dust bubble of 16 arcsec in radius probably linked to the O-type star HD117797 located at 4 kpc. The distribution of the near and mid infrared emission  indicate that warm dust  is  associated with the bubble.    


Fil: Cappa, Cristina Elisabeth. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto Argentino de Radioastronomia (i);
Fil: Rubio, R.. Universidad de Chile;
Fil: Romero, Gisela Andrea. Universidad Nacional de la Plata. Facultad de Cs.astronomicas y Geofisicas;
Fil: Duronea, Nicolas Urbano. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - la Plata. Instituto Arg.de Radioastronomia (i);
Fil: Firpo, Verónica. Universidad de la Serena;