Resumo:
The study of chemical evolution is of great importance for comprehending the evolution
of the Universe. Models and observations indicate an inside-out scenario for the formation
of spiral galaxy disks. Chemical abundance gradients, in some cases, deviate from a simple
straight line with a negative slope, showing an inner drop and/or an outer flattening,
especially in galaxies of higher masses. In this work, we analyzed the oxygen abundance
gradients of spiral galaxies using observations from the Calar Alto Legacy Integral Field
Area (CALIFA) survey. Specifically, our focus was on the analysis of oxygen abundance
gradient profiles in H II regions displaying an inner drop, with a particular emphasis on
the inner radial gradient, employing an automatic fitting procedure. We attempted to
establish relationships between the physical properties of galaxies and bulges when an
inner drop is present, aiming to provide possible explanations for the occurrence of these
breaks in gradients. We observed that the selection criteria for H II regions available
in the literature affect the results, potentially significantly altering abundance gradient
profiles and identifying different galaxies with an inner drop. Moreover, we conducted an
analysis of abundance gradients, investigating the influence of diffuse ionized gas (DIG)
decontamination on oxygen abundance gradients characterized by an inner drop. Our
findings indicate that DIG, predominantly concentrated in the central regions of galaxies,
has the potential to modify the profiles of oxygen abundance gradients in the absence of
decontamination procedures.
