High-Velocity Molecular Clouds in M83

Fuente: arXiv
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Main Authors: Nagata, Maki, Egusa, Fumi, Maeda, Fumiya, Tokuda, Kazuki, Kohno, Kotaro, Morokuma-Matsui, Kana, Koda, Jin
Format: Preprint
Published: 2025
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_version_ 1866908428471894016
author Nagata, Maki
Egusa, Fumi
Maeda, Fumiya
Tokuda, Kazuki
Kohno, Kotaro
Morokuma-Matsui, Kana
Koda, Jin
author_facet Nagata, Maki
Egusa, Fumi
Maeda, Fumiya
Tokuda, Kazuki
Kohno, Kotaro
Morokuma-Matsui, Kana
Koda, Jin
contents High-velocity clouds (HVCs), which are gas clouds moving at high velocity relative to the galactic disk, may play a critical role in galaxy evolution, potentially supplying gas to the disk and triggering star formation. In this study, we focus on the nearby face-on barred spiral galaxy M83, where high spatial resolution, high-sensitivity CO (1-0) data are available. We identified molecular clouds and searched for clouds with velocities deviating by more than 50km/s from the disk velocity field as HVCs. A total of 10 HVCs were detected -- nine redshifted and one blueshifted -- clearly highlighting an asymmetry in their velocity distribution. These HVCs have radii of 30-80 pc, masses on the order of $10^5 M_\odot$, and velocity dispersions of 3-20 km/s, displaying a tendency toward higher velocity dispersion compared to disk molecular clouds in M83. Most of the HVCs do not overlap with the candidates of supernova remnants, and the energy needed to drive HVCs at such high velocities exceeds single supernova energy. Together with the asymmetry in their velocity distribution, we thus conclude that most of the HVCs found in this study are inflow from outside the M83's disk.
format Preprint
id arxiv_https___arxiv_org_abs_2505_12757
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle High-Velocity Molecular Clouds in M83
Nagata, Maki
Egusa, Fumi
Maeda, Fumiya
Tokuda, Kazuki
Kohno, Kotaro
Morokuma-Matsui, Kana
Koda, Jin
Astrophysics of Galaxies
High-velocity clouds (HVCs), which are gas clouds moving at high velocity relative to the galactic disk, may play a critical role in galaxy evolution, potentially supplying gas to the disk and triggering star formation. In this study, we focus on the nearby face-on barred spiral galaxy M83, where high spatial resolution, high-sensitivity CO (1-0) data are available. We identified molecular clouds and searched for clouds with velocities deviating by more than 50km/s from the disk velocity field as HVCs. A total of 10 HVCs were detected -- nine redshifted and one blueshifted -- clearly highlighting an asymmetry in their velocity distribution. These HVCs have radii of 30-80 pc, masses on the order of $10^5 M_\odot$, and velocity dispersions of 3-20 km/s, displaying a tendency toward higher velocity dispersion compared to disk molecular clouds in M83. Most of the HVCs do not overlap with the candidates of supernova remnants, and the energy needed to drive HVCs at such high velocities exceeds single supernova energy. Together with the asymmetry in their velocity distribution, we thus conclude that most of the HVCs found in this study are inflow from outside the M83's disk.
title High-Velocity Molecular Clouds in M83
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2505.12757