Hydrodynamic simulations of the Disc of Gas Around Supermassive black holes (HDGAS) -II; The transition from neutral atomic to molecular gas phases

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Raouf, Mojtaba, Viti, Serena, Karimi, Reihaneh, Richings, Alexander J.
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909561994084352
author Raouf, Mojtaba
Viti, Serena
Karimi, Reihaneh
Richings, Alexander J.
author_facet Raouf, Mojtaba
Viti, Serena
Karimi, Reihaneh
Richings, Alexander J.
contents We use HDGAS hydrodynamic simulations to study the impact of active galactic nucleus (AGN) feedback on the conversion of atomic-gas to molecular-gas within the circumnuclear-disc (CND) of a typical AGN-dominated galaxy. The comparison of CI, CII, and CO line intensities and their ratios in the HDGAS post-processing radiative-transfer analysis reveals the complex interplay between AGN-activity, cold molecular gas properties, and the physical processes governing the evolution of star-formation in galaxies. Our results demonstrate that the CI/CO intensity ratio serves as a reliable indicator of the atomic-to-molecular gas transition. We present the probability distribution function (PDF) and abundance trends of various metal species related to molecular H$2$ gas, highlighting differences in clumpiness and intensity maps between AGN feedback and NoAGN models. The profile of the integrated intensity (moment-0) maps shows that the AGN-feedback model exhibits a lower CI/CO intensity ratio in the vicinity of the supermassive black hole (< 50 pc), indicating a smaller atomic-gas abundance and the presence of positive AGN-feedback. Our simulations have successfully predicted the presence of faint-CO emissions extending to larger radii from the galactic center. We also explore the relationships between CII/CO and CI/CII intensity ratios, as well as the ratios versus CO intensity, which provides insights into the "CO-dark" issues. One notable feature in the later time-scale of the AGN model is the presence of a "CO-dark" region, where the intensity of CO emission ($\rm I_{CO}$) is depleted relative to the H$_2$ column density ($N_{\rm H_2}$) compared to the NoAGN model.
format Preprint
id arxiv_https___arxiv_org_abs_2504_01776
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Hydrodynamic simulations of the Disc of Gas Around Supermassive black holes (HDGAS) -II; The transition from neutral atomic to molecular gas phases
Raouf, Mojtaba
Viti, Serena
Karimi, Reihaneh
Richings, Alexander J.
Astrophysics of Galaxies
We use HDGAS hydrodynamic simulations to study the impact of active galactic nucleus (AGN) feedback on the conversion of atomic-gas to molecular-gas within the circumnuclear-disc (CND) of a typical AGN-dominated galaxy. The comparison of CI, CII, and CO line intensities and their ratios in the HDGAS post-processing radiative-transfer analysis reveals the complex interplay between AGN-activity, cold molecular gas properties, and the physical processes governing the evolution of star-formation in galaxies. Our results demonstrate that the CI/CO intensity ratio serves as a reliable indicator of the atomic-to-molecular gas transition. We present the probability distribution function (PDF) and abundance trends of various metal species related to molecular H$2$ gas, highlighting differences in clumpiness and intensity maps between AGN feedback and NoAGN models. The profile of the integrated intensity (moment-0) maps shows that the AGN-feedback model exhibits a lower CI/CO intensity ratio in the vicinity of the supermassive black hole (< 50 pc), indicating a smaller atomic-gas abundance and the presence of positive AGN-feedback. Our simulations have successfully predicted the presence of faint-CO emissions extending to larger radii from the galactic center. We also explore the relationships between CII/CO and CI/CII intensity ratios, as well as the ratios versus CO intensity, which provides insights into the "CO-dark" issues. One notable feature in the later time-scale of the AGN model is the presence of a "CO-dark" region, where the intensity of CO emission ($\rm I_{CO}$) is depleted relative to the H$_2$ column density ($N_{\rm H_2}$) compared to the NoAGN model.
title Hydrodynamic simulations of the Disc of Gas Around Supermassive black holes (HDGAS) -II; The transition from neutral atomic to molecular gas phases
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2504.01776