Centro de Astrobiología

The role of low-mass star clusters in the formation of massive stars
24-07-2014 TESIS DEL CAB

Víctor M. Rivilla defendió en la Sala de Grados del Módulo 8 de la Facultad de Ciencias de la Universidad Autónoma de Madrid su trabajo de tesis titulado "The role of low-mass star clusters in the formation of massive stars" dirigido por Jesús Martín-Pintado obteniendo la calificación de Sobresaliente "Cum Laude".

Despite the importance of massive stars as the main source of energy  injection into the ISM of galaxies, their formation process is not  clearly understood. To distinguish between the different theories it  is crucial to establish how the parental cloud fragments by studying  the distribution of low-mass stars in massive star cradles. The  detection of this population is a challenge because it is highly  embedded in the natal molecular material. Only deep IR, X-ray and  radio/(sub)millimeter observations are able to penetrate into the  massive star cradles and reveal the stellar population.

I have analyzed deep X-ray and IR archival surveys towards 3 nearby  massive star forming regions (Orion, DR21 and Monoceros R2). I have  studied the properties of the low-mass stellar population (e.g.,  spatial distribution, clustering, stellar densities, extinction  distribution, evolutionary stages), and their feedback into the  star-forming environment. In particular, I have evaluated how the  outflow-driven turbulence in dense subclusters of low-mass stars can  affect the formation of massive stars. I discuss my results in the  context of the different massive star formation theories.

I will also present new Very Large Array (VLA) and Submillimeter Array  (SMA) observations of Orion and Monoceros R2, respectively. The  multi-epoch VLA continuum data has allowed to study the nature of the  radiovariability of Orion young stars. The SMA observations have  revealed bright continuum emission and molecular hot cores towards the  more massive stars and 11 previously unknown CO molecular outflows  from the embedded stellar cluster.

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