Identification of specific molecular species and investigation of their distribution around two deeply embedded protostars (IRAS 16293-2422) observed with ALMA

Grieco, Francesco (2016) Identification of specific molecular species and investigation of their distribution around two deeply embedded protostars (IRAS 16293-2422) observed with ALMA. [Laurea magistrale], Università di Bologna, Corso di Studio in Astrofisica e cosmologia [LM-DM270]
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Abstract

In this project I have worked with high spatial and spectral resolution data on the protostellar binary system IRAS 16293-2422 obtained with Atacama Large Millimeter-submillimeter Array (ALMA). I focused in particular on one of the two sources, IRAS 16293A, which is a Class 0 protostar. IRAS 16293A has a much more complicated structure than its companion, it has indeed two outflows, along NE-SW and E-W directions, and the continuum emission appears to be one at sub-mm wavelengths but split into two at mm and cm wavelengths. Line emission toward this source is also characterized by FWHMs much higher than those observed toward IRAS 16293B, causing some lines to blend. Thus, in order to give a contribution toward the clarification of how these dynamics work, I investigated how different species are affected through studying their distribution and velocity. To do this I mapped integrated emission (Moment 0 maps) and velocity distribution (Moment 1 maps) for 33 different transitions from various species. It turned out that all species peak close to the continuum source (which represents the accretion disk) but most of the peaks present an offset towards South West, probably because of the influence of NE-SW outflow. Moreover, using rotational diagrams, I have been able to estimate methanol temperature and column density in every pixel around Source A. The temperature map doesn’t show increasing temperatures towards the center, as one would expect getting closer to the protostar, but warmer zones in the eastern and in the western part of methanol emitting region, where all methanol lines show kinetic deformation. Furthermore, methanol transitions Moment 0 maps are characterized by the presence of a horizontally elongated structure, in the lower part of methanol emitting region. I discuss how both these methanol emission features are compatible with the action of shocks generated by E-W outflow.

Abstract
Tipologia del documento
Tesi di laurea (Laurea magistrale)
Autore della tesi
Grieco, Francesco
Relatore della tesi
Correlatore della tesi
Scuola
Corso di studio
Ordinamento Cds
DM270
Parole chiave
protostellar,Class 0,IRAS 16293-2422,ALMA,distribution,outflow,methanol
Data di discussione della Tesi
16 Dicembre 2016
URI

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