Title: Understanding the Baryon Cycle: Fueling Star Formation via Inflows in Milky Way-like Galaxies Show Chinese title

Title: 理解重子循环：通过流入为类似银河系的星系中的恒星形成提供燃料

Abstract: Galaxies are not isolated systems; they continuously interact with their surroundings by ejecting gas via stellar feedback and accreting gas from the environment. Understanding the interplay between outflows from the disc and the surrounding circumgalactic medium (CGM) is key to learning how star-forming galaxies evolve. Our goal is to understand how gas in the CGM is accreted onto the inner regions of the disc, making it available for the formation of stars, exploring the connection between stellar feedback and gas accretion from the CGM in Milky Way-like galaxies. We focus on the distribution of vertical and radial gas flows to and from the disc as a function of galactocentric radius, and examine the implications of these processes for the evolution of such galaxies. We use the Arepo code coupled with the SMUGGLE sub-grid model to perform hydrodynamic N-body simulations of 9 different galaxies surrounded by a hot CGM. Each simulation features a gaseous disc with different mass and scale length, allowing us to examine how disc structure impacts gas dynamics. We find evidence of a crucial link between stellar feedback and gas accretion from the CGM, which together play an essential role in sustaining ongoing star formation in the disc. In particular, the ejection of gas from the disc plane by stellar feedback leads to the generation of a baryon cycle in which the CGM gas is mainly accreted onto the external regions of the disc ($ \approx 3-10$ M$_{\odot}$ yr$^{-1}$ of gas is accreted into the whole disc). From these regions it is then transported to the centre with radial mass rates $\approx 1-4$ M$_{\odot}$ yr$^{-1}$ on average, owing to angular momentum conservation, forming new stars and starting the whole cycle again. We find that both vertical accretion onto the inner regions of the disc and the radial transport of gas from the disc outskirts are necessary to sustain star formation. Show Chinese abstract

Abstract: 星系并非孤立系统；它们通过恒星反馈抛出气体并从周围环境中吸积气体，从而持续与周边环境相互作用。 理解盘风与周围星系际介质（CGM）之间的相互作用对于了解恒星形成星系的演化至关重要。 我们的目标是理解星系际介质中的气体是如何被吸积到盘的内区，使其可用于恒星形成，并探索类似银河系的星系中恒星反馈与星系际介质气体吸积之间的联系。 我们着重研究了垂直和径向气体流动在星系中心距（galactocentric radius）不同情况下的分布，并探讨这些过程对星系演化的影响。 我们使用Arepo代码结合SMUGGLE子网格模型，对9个被热CGM包围的不同星系进行了流体力学N体模拟。 每个模拟都具有不同质量和尺度长度的气盘，这使我们可以研究盘结构如何影响气体动力学。 我们发现了恒星反馈与星系际介质气体吸积之间存在关键联系，二者共同在维持盘中持续恒星形成方面发挥着重要作用。 特别是，恒星反馈将气体从盘面喷射出去，导致一个重子循环的产生，在该循环中，CGM气体主要被吸积到盘的外部区域（$ \approx 3-10$M$_{\odot}$年$^{-1}$的气体被吸积到整个盘中）。 然后由于角动量守恒，这些区域的气体以平均径向质量率$\approx 1-4$M$_{\odot}$年$^{-1}$被输运到中心，形成新恒星并开始新的循环。 我们发现，维持恒星形成既需要盘内区的垂直吸积，也需要从盘外围向外输送气体。