Transport-driven super-Jeans fragmentation in dynamical star-forming regions
Fuente:
arXiv
Guardado en:
| Autor principal: | |
|---|---|
| Formato: | Preprint |
| Publicado: |
2024
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866929227014602752 |
|---|---|
| author | Li, Guang-Xing |
| author_facet | Li, Guang-Xing |
| contents | The Jeans criterion is one cornerstone in our understanding of gravitational fragmentation. A critical limitation of the Jeans criterion is that the background density is assumed to be a constant, which is often not true in dynamic conditions such as star-forming regions. For example, during the formation phase of the high-density gas filaments in a molecular cloud, a density increase rate $\dot ρ$ implies a mass accumulation time of $t_{\rm acc}= ρ/ \dot ρ= - ρ(\nabla \cdot (ρ\vec{v}))^{-1}$. The system is non-stationary when the mass accumulation time becomes comparable to the free-fall time $t_{\rm ff} = 1 / \sqrt{G ρ}$. We study fragmentation in non-stationary settings, and find that accretion can significantly increase in the characteristic mass of gravitational fragmentation ( $λ_{\rm Jeans,\; aac}= λ_{\rm Jeans} (1 + t_{\rm ff} / t_{\rm acc})^{1/3}$, $m_{\rm Jeans,\, acc} = m_{\rm Jeans} (1 + t_{\rm ff} / t_{\rm acc})$). In massive star-forming regions, this mechanism of transport-driven super-jeans fragmentation can contribute to the formation of massive stars by causing order-of-magnitude increases in the mass of the fragments. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2401_16083 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Transport-driven super-Jeans fragmentation in dynamical star-forming regions Li, Guang-Xing Astrophysics of Galaxies The Jeans criterion is one cornerstone in our understanding of gravitational fragmentation. A critical limitation of the Jeans criterion is that the background density is assumed to be a constant, which is often not true in dynamic conditions such as star-forming regions. For example, during the formation phase of the high-density gas filaments in a molecular cloud, a density increase rate $\dot ρ$ implies a mass accumulation time of $t_{\rm acc}= ρ/ \dot ρ= - ρ(\nabla \cdot (ρ\vec{v}))^{-1}$. The system is non-stationary when the mass accumulation time becomes comparable to the free-fall time $t_{\rm ff} = 1 / \sqrt{G ρ}$. We study fragmentation in non-stationary settings, and find that accretion can significantly increase in the characteristic mass of gravitational fragmentation ( $λ_{\rm Jeans,\; aac}= λ_{\rm Jeans} (1 + t_{\rm ff} / t_{\rm acc})^{1/3}$, $m_{\rm Jeans,\, acc} = m_{\rm Jeans} (1 + t_{\rm ff} / t_{\rm acc})$). In massive star-forming regions, this mechanism of transport-driven super-jeans fragmentation can contribute to the formation of massive stars by causing order-of-magnitude increases in the mass of the fragments. |
| title | Transport-driven super-Jeans fragmentation in dynamical star-forming regions |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2401.16083 |