银河宇宙射线是星际气体电离的普遍来源,与紫外线和X射线光子以及自然放射性竞争,确定分子云和周星盘中电子、离子和带电尘埃颗粒的丰度。我们模拟了银河系宇宙射线的不同成分与气体柱密度的传播。我们的研究集中在高密度的传播,在几克厘米$^{-2}$以上,特别是有关的内部地区的坍缩云和星周盘。初级和次级CR粒子(质子和较重的原子核,电子,正电子和光子)的传播计算在连续减速近似,扩散近似,或灾难性的近似,通过采用不同的传输制度的匹配程序。适当制度的选择取决于主要损失过程的性质,模拟为连续或灾难性的。CR电离速率由CR质子及其低于$\approx 130$ g cm $^{-2}$的次级电子和由高于$\approx600$ g cm $^{-2}$的光子衰变产生的电子/正电子对确定。我们表明,一个适当的描述的粒子运输是必不可少的计算在后一种情况下的电离率,因为电子/正电子差分通量敏感地依赖于质子和光子的通量。我们的研究结果表明,CR电离率在高密度环境中,如,例如,坍缩分子云的内部或星周盘的中平面,比以前假设的要大。它不会随着柱密度的增加而呈指数下降,而是由于控制次级粒子的产生和传播的不同过程的相互作用而遵循更复杂的行为。
英文摘要:
Galactic cosmic rays are a ubiquitous source of ionisation of the interstellar gas, competing with UV and X-ray photons as well as natural radioactivity in determining the fractional abundance of electrons, ions and charged dust grains in molecular clouds and circumstellar discs. We model the propagation of different components of Galactic cosmic rays versus the column density of the gas. Our study is focussed on the propagation at high densities, above a few g cm$^{-2}$, especially relevant for the inner regions of collapsing clouds and circumstellar discs. The propagation of primary and secondary CR particles (protons and heavier nuclei, electrons, positrons, and photons) is computed in the continuous slowing down approximation, diffusion approximation, or catastrophic approximation, by adopting a matching procedure for the different transport regimes. A choice of the proper regime depends on the nature of the dominant loss process, modelled as continuous or catastrophic. The CR ionisation rate is determined by CR protons and their secondary electrons below $\approx 130$ g cm$^{-2}$ and by electron/positron pairs created by photon decay above $\approx600$ g cm$^{-2}$. We show that a proper description of the particle transport is essential to compute the ionisation rate in the latter case, since the electron/positron differential fluxes depend sensitively on the fluxes of both protons and photons. Our results show that the CR ionisation rate in high-density environments, like, e.g., the inner parts of collapsing molecular clouds or the mid-plane of circumstellar discs, is larger than previously assumed. It does not decline exponentially with increasing column density, but follows a more complex behaviour due to the interplay of different processes governing the generation and propagation of secondary particles.
Massive stars exploding in a He-rich circumstellar medium XII. SN 2024acyl: A fast, linearly declining Type Ibn supernova with early flash-ionisation features
Yunnan Observatories, Chinese Academy of Sciences(中国科学院云南天文台);International Centre of Supernovae, Yunnan Key Laboratory(超新星国际中心,云南省重点实验室);INAF - Osservatorio Astronomico di Padova(意大利国家天体物理研究所帕多瓦天文台);Department of Astronomy, Kyoto University(京都大学天文学系);South-Western Institute for Astronomy Research, Yunnan University(云南大学西南天文研究所);Yunnan Key Laboratory of Survey Science, Yunnan University(云南大学云南省测绘科学重点实验室);School of Astronomy and Space Science, University of Chinese Academy of Sciences(中国科学院大学天文与空间科学学院);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);School of Electronic Science and Engineering, Chongqing University of Posts and Telecommunications(重庆邮电大学电子科学与工程学院);INAF - Osservatorio Astronomico di Brera(意大利国家天体物理研究所布雷拉天文台);INAF - Osservatorio Astronomico d’Abruzzo(意大利国家天体物理研究所阿布鲁佐天文台)
SN 2024acyl 是一种快速、线性衰减的 Type Ibn 超新星,具有早期闪光电离特征,其光谱和光变曲线特征支持由抛射物与 CSM 交互驱动的 SN 模型。
On the driver of relativistic effects strength in Seyfert galaxies
超大质量黑洞吸积盘中X射线谱线的研究是研究吸积流物理和几何的重要手段之一,同时也为黑洞的自旋提供了理论上的观测约束。[...]我们的目标是确定这种相对论性再处理功能的强度的最终物理驱动程序。我们首先将目前研究的塞弗特星系的硬X射线通量限制样本(FERO,de la Calle Perez et al. 2010)扩展到柱密度N_H=6x10^23 atoms/cm/cm的遮蔽天体。我们验证,没有线属性依赖于活动星系核的光学分类,预期从塞弗特统一方案。也没有相关的吸积盘的倾角,从正式拟合的线配置文件,和光学类型或宿主星系的方位角,这表明吸积盘和宿主星系平面的最里面的区域不对齐。[...].数据对线发射盘的详细电离状态不够敏感。然而,缺乏依赖性的线EW上的光度或静止帧质心能量排除了光盘电离在EW的动态范围在塞弗茨起着重要的作用。相对论性加宽的K-α铁线EW的动力学范围在附近的Seyferts似乎主要是由最里面的吸积流的属性。我们讨论了几种机制(光盘电离,光盘截断,由于轻度相对论外流电晕畸变),可以解释这一点。[...]观测数据仍然不矛盾的情况下调用不同的机制的光谱复杂性周围的铁线,最值得注意的是“部分覆盖”吸收的情况。(节略)。