Integral field spectroscopy of (U)LIRGs and Post-Starburst QSOs : the role of mergers in galaxy evolution

Major gas-rich mergers are thought to be responsible of a dramatic evolution of galaxies. Attending to the changes in the morphology, Kormendy & Sanders (1992) propose that mergers of gas rich disks (U/LIRGs) lead to the formation of elliptical galaxies. Due to the large timescales needed to com...

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Detalles Bibliográficos
Autor: Cortijo Ferrero, Clara
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/133484
Acceso en línea:http://hdl.handle.net/10261/133484
Access Level:acceso abierto
Palabra clave:Galaxies
Espectroscopía astrofísica
Astronomía y Astrofísica
Descripción
Sumario:Major gas-rich mergers are thought to be responsible of a dramatic evolution of galaxies. Attending to the changes in the morphology, Kormendy & Sanders (1992) propose that mergers of gas rich disks (U/LIRGs) lead to the formation of elliptical galaxies. Due to the large timescales needed to complete the merger, we cannot study this process following the transformation of an individual system. Instead, we need to compare the properties of systems along the different stages of the merger sequence. However, identifying all the intermediate stages of a merger and placing them in the right evolutionary order it is not an easy task. Moreover, apart from the morphological changes, Sanders et al. (1988) propose there is also a change in the ionizing mechanism along the merger sequence, from dusty starbursts in the initial stages (U/LIRGs) to unobscured QSO activity in the final ones. While it is quite clear that mergers lead to massive starburst activity, sometimes hidden by dust, and therefore, U/LIRGs (Surace et al. 2000; Veilleux et al. 2002; Kim et al. 2013), it is not so clear if the QSOs activity is merger triggered and if so, when exactly during the merger it starts. The best approach is to find systems with intermediate properties in the proposed sequence, that is, galaxies hosting bright nuclear QSOs, showing morphological disturbance typical of a past merger and with an important post-starburst population, relics of the intense starburst activity triggered in the past. The best example of this kind of systems are post-starburst QSOs (Brotherton et al., 1999; Cales et al. 2011, 2013, 2015), which have been proposed to be the missing evolutionary link. They are, therefore, ideal laboratories to study connections between the starburst and AGN phenomenon.