AI 中文总结
研究宇宙射线对冷流的加热，通过耦合CR输运计算与冷流解析模型，发现外部CRs能改变冷流热状态，使其在特定条件下更易被扰乱，还会影响大质量星系气体供应和增长，为冷气体吸积引入选择性。
AI 中文摘要
近期观测表明宇宙网细丝中存在宇宙射线（CRs）。在宇宙正午期间，冷流从这些细丝向大质量星系供应气体流入。由于这些流预计被磁化，外部宇宙网CRs可能随流入气体夹带。本研究旨在确定外部供应的CRs群体是否能沉积能量改变或扰乱星系的冷气体供应。通过将光谱分辨的CR输运计算与星系晕中依赖红移的磁化冷流解析模型耦合，研究外部供应的CRs是否能通过此渠道改变气体供应。结果发现CR能量沉积可改变冷流的热状态。致密流核基本保持弹性，仅经历微弱加热，温度升高不到10倍，不足以克服流与星系晕周围介质（CGM）界面的辐射冷却。在更弥散的流以及最巨大晕在质心半径附近的部分混合界面气体中，CR加热变得足够强，辐射冷却无法再平衡，气体被加热至混合层温度或更高。这削弱了流的稳定性，使其更易被扰乱。完全蒸发仅在极端情况下可能。因此，冷流在更大的星系中心半径、更高的晕质量以及更弥散或部分混合的流物质中更容易受到CR加热。通过优先加热弥散气体，外部供应的CRs可能为冷气体吸积引入额外选择性，改变大质量星系的气体供应和增长。这些CRs削弱脆弱流并侵蚀其冷包层，可能导致存活的冷流成分在星系晕深处显得更薄且更尖锐受限。
英文摘要
Recent observations have demonstrated the presence of cosmic rays (CRs) in cosmic-web filaments. Cold streams supply gas inflows from these filaments into massive galaxies during the cosmic noon. As these streams are expected to be magnetised, external cosmic-web CRs may become entrained with this inflowing gas. We aim to determine whether this externally-supplied CR population can deposit energy to alter or disrupt the supply of cold gas to galaxies. We couple a spectrally-resolved CR transport calculation to a redshift-dependent analytical model of magnetised cold streams in galaxy haloes and investigate whether externally-supplied CRs can modify gas supply through this channel. We find CR energy deposition can alter the thermal state of cold streams. Dense stream cores remain largely resilient and only experience weak heating. Their temperature is raised by less than a factor of 10, which is insufficient to overcome radiative cooling at the stream-CGM interface. In more diffuse streams, and in partially mixed interface gas of the most massive haloes near the virial radius, CR heating becomes strong enough that radiative cooling can no longer balance it, and the gas is heated toward or above the mixing-layer temperature. This weakens the stability of the stream, making it more susceptible to disruption. Complete evaporation is possible only in extreme cases. Cold streams are therefore more vulnerable to CR heating at larger galactocentric radii, higher halo masses, and in more diffuse or partially-mixed stream material. By preferentially heating diffuse gas, externally supplied CRs may introduce additional selectivity into cold-gas accretion that modifies the gas supply and growth of massive galaxies. These CRs weaken fragile streams and erode their cold envelope, and may cause surviving cold flow components to appear thinner and more sharply confined far into galaxy haloes.
Comments23 pages, 13 figures, 1 table. Submitted to A&A
