Ionization Conditions in the Central Giant HII Region of NGC 5253

TL;DR

This study investigates the ionization conditions and chemical abundances in the central region of NGC 5253, revealing nitrogen excess in different gas components and linking broad emission lines to material expelled by super star clusters.

Contribution

It provides detailed 2D spectroscopic analysis of ionization and chemical patterns in NGC 5253, highlighting nitrogen excess and kinematic distinctions.

Findings

All kinematic components show nitrogen excess.

Broad component has larger nitrogen excess than narrow.

Broad component linked to expelled material from super star clusters.

Abstract

We are carrying out a detailed 2D spectroscopic study of the central 210 pc X 130 pc of the blue compact dwarf (BCD) galaxy NGC5253. This contribution presents the ionization conditions and chemical abundance patterns for the different kinematic components of the ionized gas detected in our previous work. All the kinematic components present an excess in nitrogen abundance. In particular, the broad velocity component has larger excess than the narrow one by a factor of ~1.4+-0.4 which is consistent with a scenario for the Giant HII Region where the broad component of the emission lines traces the material expelled by the two central Super Star Clusters while the narrow one is associated to previously existing ionized gas.