The locations of recent supernovae near the Sun from modelling 60Fe transport
The locations of recent supernovae near the Sun from modelling 60Fe transport
复制标题
根据 60Fe 传输模型得出的太阳附近近期超新星的位置
作者：
D. Breitschwerdt;J. Feige;M. Schulreich;M. Avillez;C. Dettbarn;B. Fuchs
深海地壳中的60 Fe特征表明，大约220万年前，一颗或多颗超新星在太阳附近爆炸。最近的同位素分析与发生在距离太阳60到130秒差距的核心坍缩或电子捕获超新星相一致。此外，宇宙射线光谱的特殊性指向了大约200万年前附近的超新星。太阳系所处的局部热等离子体气泡，起源于一个移动的超新星群中的14到20颗超新星，其幸存的成员现在在天蝎座-半人马座星协中。在这里，我们报告计算的最可能的轨迹和质量的超新星祖先，因此，他们的爆炸时间和地点。60 Fe信号来自两颗超新星，距离在90到100秒差距之间。最近的一次发生在230万年前，在现在的银河系坐标l = 327°，B = 11°，第二次最近的爆炸发生在大约150万年前，在l = 343°，B = 25°，质量分别是太阳质量的9.2倍和8.8倍。剩下的超新星，形成了局部气泡，贡献较小，因为它们发生在更远的距离和更长的时间（60 Fe的半衰期为260万年）。有不确定性有关的核合成产额和损失的60 Fe在运输过程中，但他们不影响的相对分布的60 Fe在地壳层，因此我们的模型再现测量的相对丰度非常好。
The signature of 60Fe in deep-sea crusts indicates that one or more supernovae exploded in the solar neighbourhood about 2.2 million years ago. Recent isotopic analysis is consistent with a core-collapse or electron-capture supernova that occurred 60 to 130 parsecs from the Sun. Moreover, peculiarities in the cosmic ray spectrum point to a nearby supernova about two million years ago. The Local Bubble of hot, diffuse plasma, in which the Solar System is embedded, originated from 14 to 20 supernovae within a moving group, whose surviving members are now in the Scorpius–Centaurus stellar association. Here we report calculations of the most probable trajectories and masses of the supernova progenitors, and hence their explosion times and sites. The 60Fe signal arises from two supernovae at distances between 90 and 100 parsecs. The closest occurred 2.3 million years ago at present-day galactic coordinates l = 327°, b = 11°, and the second-closest exploded about 1.5 million years ago at l = 343°, b = 25°, with masses of 9.2 and 8.8 times the solar mass, respectively. The remaining supernovae, which formed the Local Bubble, contribute to a smaller extent because they happened at larger distances and longer ago (60Fe has a half-life of 2.6 million years). There are uncertainties relating to the nucleosynthesis yields and the loss of 60Fe during transport, but they do not influence the relative distribution of 60Fe in the crust layers, and therefore our model reproduces the measured relative abundances very well.