Graph Theoretical Analysis of local ultraluminous infrared galaxies and quasars
arXiv:2307.14746 · doi:10.1016/j.ascom.2023.100742
Abstract
We present a methodological framework for studying galaxy evolution by utilizing Graph Theory and network analysis tools. We study the evolutionary processes of local ultraluminous infrared galaxies (ULIRGs) and quasars and the underlying physical processes, such as star formation and active galactic nucleus (AGN) activity, through the application of Graph Theoretical analysis tools. We extract, process and analyse mid-infrared spectra of local (z < 0.4) ULIRGs and quasars between 5-38 microns through internally developed Python routines, in order to generate similarity graphs, with the nodes representing ULIRGs being grouped together based on the similarity of their spectra. Additionally, we extract and compare physical features from the mid-IR spectra, such as the polycyclic aromatic hydrocarbons (PAHs) emission and silicate depth absorption features, as indicators of the presence of star-forming regions and obscuring dust, in order to understand the underlying physical mechanisms of each evolutionary stage of ULIRGs. Our analysis identifies five groups of local ULIRGs based on their mid-IR spectra, which is quite consistent with the well established fork classification diagram by providing a higher level classification. We demonstrate how graph clustering algorithms and network analysis tools can be utilized as unsupervised learning techniques for revealing direct or indirect relations between various galaxy properties and evolutionary stages, which provides an alternative methodology to previous works for classification in galaxy evolution. Additionally, our methodology compares the output of several graph clustering algorithms in order to demonstrate the best-performing Graph Theoretical tools for studying galaxy evolution.
Accepted for publication in Astronomy and Computing
References in corpus (21)
- Fast unfolding of communities in large networks
- Finding community structure in networks using the eigenvectors of matrices
- The Host Galaxies and Classification of Active Galactic Nuclei
- The Herschel view of the dominant mode of galaxy growth from z=4 to the present day
- Mid-IR Galaxy Classification Based on Silicate Obscuration and PAH Equivalent Width
- Dust in starburst nuclei and ULIRGs: SED models for observers
- A Spitzer IRS Low-Resolution Spectroscopic Search for Buried AGNs in Nearby Ultraluminous Infrared Galaxies - A Constraint on Geometry between Energy Sources and Dust -
- PAH Emission from Ultraluminous Infrared Galaxies
- CASSIS: The Cornell Atlas of Spitzer/Infrared Spectrograph Sources. II. High-resolution observations
- Modelling the spectral energy distribution of ULIRGs II: The energetic environment and the dense interstellar medium
- HELP: The Herschel Extragalactic Legacy Project
- Decomposing Dusty Galaxies. I. Multi-Component Spectral Energy Distribution Fitting
- HELP: A catalogue of 170 million objects, selected at 0.36-4.5 m, from 1270 deg. of prime extragalactic fields
- Star formation and nuclear activity in luminous infrared galaxies: An infrared through radio review
- Extreme star formation events in quasar hosts over
- A new look at local ultraluminous infrared galaxies: the atlas and radiative transfer models of their complex physics
- An Evolutionary Paradigm for Dusty Active Galaxies at Low Redshift
- Graph Database Solution for Higher Order Spatial Statistics in the Era of Big Data
- A hyperluminous obscured quasar at a redshift of z ~ 4.3
- Network Analysis of Cosmic Structures : Network Centrality and Topological Environment
- Classification of local ultraluminous infrared galaxies and quasars with kernel principal component analysis