Evolution of molecular clouds on galaxy-cloud scale revealed by gravitational network analysis : High-mass clouds may deplete nearby gas via accretion or merging

Fuente: arXiv
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Main Authors: Zhou, J. W., Li, Guang-Xing
Format: Preprint
Published: 2025
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author Zhou, J. W.
Li, Guang-Xing
author_facet Zhou, J. W.
Li, Guang-Xing
contents Observations show that molecular gas in spiral galaxies is organized into a network of interconnected systems through the gravitational coupling of multi-scale hub-filament structures. Building on this picture, we model molecular gas in the galaxy NGC 628 as a gravitational network, where molecular clouds are represented as nodes. Through analyzing this network, we can characterize both the gravitational interactions and the physical properties of the clouds using geometry-based network metrics. A strong correlation is observed between the geometric and physical properties of the nodes (clouds). High-mass clouds tend to exhibit less clustering and greater average separations, suggesting that they generally have fewer neighbors. During their formation and evolution, high-mass clouds may deplete nearby gas via accretion or merging, leading to more isolated characteristics within the network. This aligns with observations showing a decrease in the virial ratio of molecular clouds as their mass increases. For clouds at different evolutionary stages, less evolved clouds with lower mass are typically found in tighter gravitational subnetworks, with closer proximity to neighboring clouds. As a result, they are more prone to accretion or merging during evolution.
format Preprint
id arxiv_https___arxiv_org_abs_2501_18241
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Evolution of molecular clouds on galaxy-cloud scale revealed by gravitational network analysis : High-mass clouds may deplete nearby gas via accretion or merging
Zhou, J. W.
Li, Guang-Xing
Astrophysics of Galaxies
Observations show that molecular gas in spiral galaxies is organized into a network of interconnected systems through the gravitational coupling of multi-scale hub-filament structures. Building on this picture, we model molecular gas in the galaxy NGC 628 as a gravitational network, where molecular clouds are represented as nodes. Through analyzing this network, we can characterize both the gravitational interactions and the physical properties of the clouds using geometry-based network metrics. A strong correlation is observed between the geometric and physical properties of the nodes (clouds). High-mass clouds tend to exhibit less clustering and greater average separations, suggesting that they generally have fewer neighbors. During their formation and evolution, high-mass clouds may deplete nearby gas via accretion or merging, leading to more isolated characteristics within the network. This aligns with observations showing a decrease in the virial ratio of molecular clouds as their mass increases. For clouds at different evolutionary stages, less evolved clouds with lower mass are typically found in tighter gravitational subnetworks, with closer proximity to neighboring clouds. As a result, they are more prone to accretion or merging during evolution.
title Evolution of molecular clouds on galaxy-cloud scale revealed by gravitational network analysis : High-mass clouds may deplete nearby gas via accretion or merging
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2501.18241