The shape of the ionised gas abundance distribution in spiral galaxies
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Sánchez Menguiano, LauraEditorial
Universidad de Granada
Departamento
Universidad de Granada. Departamento de Física Teórica y del Cosmos; Consejo Superior de Investigaciones Científicas (CSIC). Instituto de Astrofísica de AndalucíaMateria
Galaxias espirales Regiones H II (Astrofísica) Gases ionizados Estrellas Formación Oxígeno
Materia UDC
53 53.084.83 2200 210104
Date
2018Fecha lectura
2017-12-20Referencia bibliográfica
Sánchez Menguiano, L. The shape of the ionised gas abundance distribution in spiral galaxies. Granada: Universidad de Granada, 2018. [http://hdl.handle.net/10481/49074]
Sponsorship
Tesis Univ. Granada. Programa Oficial de Doctorado en: Física y Matemáticas; Esta tesis doctoral se ha realizado con el apoyo del MINECO a través de la ayuda BES-2013-062927 (proyectos AYA2012-31935 y AYA2016-79724-C4-4-P).Abstract
The study of the gas-phase chemical composition of spiral galaxies has
proven to be a powerful tool to improve our knowledge on the evolution
of these complex systems. In particular, the analysis of Hii regions (regions
of ionised gas associated with star formation) is of great importance, as it
is through the birth and death of stars that the galaxies chemically evolve.
In this thesis we use two sets of high-quality integral field spectroscopic
(IFS) data from two different surveys, CALIFA and AMUSING, to characterise
the oxygen abundance distribution of the ionised gas in star-forming
(SF) regions of spiral galaxies. The first survey provides a sample of 122
disc galaxies extracted from a well-defined, statistically significant mother
sample, representative of galaxies in the Local Universe. The latter provides
a sample of 102 galaxies that allows us to complement the study based on
CALIFA data using a higher spatial resolution dataset.
The abundance distribution of the analysed galaxies is determined based
on the O3N2 strong-line indicator (although others are also tested). To
measure the emission lines involved we apply FIT3D, an extensively tested
code designed to deal with spatially resolved IFS data.
The study of the 2-dimensional (2D) ionised gas abundance distribution
is addressed by analysing separately the radial and azimuthal trends. The
large number of SF regions provided by both analysed samples, together
with the good coverage of the galaxy discs with high spatial resolution,
allow us to undertake this study as never done before. To sum up, this thesis comprises the most complete 2D characterisation
of the oxygen abundance distribution of the ionised gas in a large and statistically
significant sample of spiral galaxies up to date. We show that this
distribution display a wide range of features such as inner drops, outer flattenings,
and azimuthal variations, as opposed to the simplistic view of a single
radial decline. These features display clear trends with galaxy properties
such as spiral structure, mass, or bar presence. These results provide strong
constraints to chemical evolution models aimed at explaining the formation
and evolution of spiral galaxies, trying to do our bit in the comprehension
of the Universe around us.