Alternative diagnostic diagrams for active galactic nuclei based on optical emission lines

• Grant number: 19/16488-9
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2019
• End date: July 31, 2021
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Claudia Lucia Mendes de Oliveira
• Grantee: Catarina Pasta Aydar
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Nuclei of galaxies with emission lines are usually classified into two broad categories: H II Regions and Active Galactic Nuclei (AGN), depending on the nature of the ionizing source. In order to classify galaxies in these categories as well as in some subcategories, diagnostic diagrams, also called BPT diagrams, are often used. These diagrams are based on axes that correspond to the ratios of the intensities of a forbidden line to a Balmer line. This strategy is subject to several limitations. We propose to study a strategy that involves these same pairs of lines, combined in a different way. The objective is to demonstrate that more reliable information can be obtained on the classification of objects. As a first goal we seek to investigate whether the objects classified as Transition are, in fact, Composite Objects or intrinsically distinct from the two main categories. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

AYDAR, Catarina Pasta. Diagnostic diagrams for the classification of galactic nuclei: comparison of traditional and alternative diagrams. 2021. Master's Dissertation - Universidade de São Paulo (USP). Instituto Astronômico e Geofísico (IAG/SBD) São Paulo.