Impacts of the Metagalactic Ultraviolet Background on Circumgalactic Medium Absorption Systems

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Taira, Elias, Kopenhafer, Claire, Oshea, Brian W., Manning, Alexis, Fuhrman, Evelyn, Peeples, Molly S., Tumlinson, Jason, Smith, Britton D.
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866908272853778432
author Taira, Elias
Kopenhafer, Claire
Oshea, Brian W.
Manning, Alexis
Fuhrman, Evelyn
Peeples, Molly S.
Tumlinson, Jason
Smith, Britton D.
author_facet Taira, Elias
Kopenhafer, Claire
Oshea, Brian W.
Manning, Alexis
Fuhrman, Evelyn
Peeples, Molly S.
Tumlinson, Jason
Smith, Britton D.
contents Among the many different pieces of physics that go into simulations of the circumgalactic medium (CGM), the metagalactic ultraviolet background (UVB) plays a significant role in determining the ionization state of different metal species. However, the UVB is uncertain with multiple models having been developed by various research groups over the past several decades. In this work, we examine how different UVB models influence the ionic column densities of CGM absorbers. We use these UVB models to infer ion number densities in the FOGGIE galaxy simulations at $z=2.5$ and use the Synthetic Absorption Line Surveyor Application (SALSA) package to identify absorbers. Absorbers are then matched across UVB models based on their line of sight position so that their column densities can be compared. From our analysis, we find that changing the UVB model produces significant changes in ionization, specifically at lower gas densities and higher temperatures where photoionization dominates over collisional ionization. We also find that the scatter of column density differences between models tends to increase with increasing ionization energy, with the exception of \hi, which has the highest scatter of all species we examined.
format Preprint
id arxiv_https___arxiv_org_abs_2503_11775
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Impacts of the Metagalactic Ultraviolet Background on Circumgalactic Medium Absorption Systems
Taira, Elias
Kopenhafer, Claire
Oshea, Brian W.
Manning, Alexis
Fuhrman, Evelyn
Peeples, Molly S.
Tumlinson, Jason
Smith, Britton D.
Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
Among the many different pieces of physics that go into simulations of the circumgalactic medium (CGM), the metagalactic ultraviolet background (UVB) plays a significant role in determining the ionization state of different metal species. However, the UVB is uncertain with multiple models having been developed by various research groups over the past several decades. In this work, we examine how different UVB models influence the ionic column densities of CGM absorbers. We use these UVB models to infer ion number densities in the FOGGIE galaxy simulations at $z=2.5$ and use the Synthetic Absorption Line Surveyor Application (SALSA) package to identify absorbers. Absorbers are then matched across UVB models based on their line of sight position so that their column densities can be compared. From our analysis, we find that changing the UVB model produces significant changes in ionization, specifically at lower gas densities and higher temperatures where photoionization dominates over collisional ionization. We also find that the scatter of column density differences between models tends to increase with increasing ionization energy, with the exception of \hi, which has the highest scatter of all species we examined.
title Impacts of the Metagalactic Ultraviolet Background on Circumgalactic Medium Absorption Systems
topic Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2503.11775