arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0709.0501astro-ph
收藏

超新星的中子感生Gamma-Ray辐射

Neutrino-Induced Gamma-Ray Emission from Supernovae

Yu Lu, Yong-Zhong Qian

摘要:

在超新星核心坍缩期间,原中子星发射的反nu_e被氢包层中的质子吸收,产生中子和正电子。中子俘获质子和正电子湮灭,然后分别产生2.22和0.511 MeV的伽马射线。我们计算了这些伽马射线的通量,预计从超新星与11兆太阳祖。质子上中子俘获的通量在564 s的时间尺度上呈指数衰减,这是由质子和3 He核上的中子衰减和俘获决定的。对于距离为1千秒差距的超新星,峰值通量为2.38 × 10 ^{-7}/cm ^2/s。正电子湮没产生的γ射线通量则与反Nu_e光度的时间演化一致,持续时间约为10 s。对于距离为1千秒差距的超新星,这种情况下的峰值通量为6.8 × 10 ^{-5}/cm ^2/s。对上述伽马射线通量的探测超出了现有仪器的能力,甚至可能超出了那些计划在不久的将来使用的仪器的能力。然而,如果能够探测到这样的通量,它们不仅构成了一种新的信号,这种信号发生在中微子信号和超新星光学显示之间的几个小时的间隙中,而且还可以提供一种有用的探测超新星祖先表层条件的方法。

英文摘要:

During a core-collapse supernova, absorption of anti-nu_e emitted from the proto-neutron star by protons in the hydrogen envelope produces neutrons and positrons. Neutron capture on protons and positron annihilation then produce gamma rays of 2.22 and 0.511 MeV, respectively. We calculate the fluxes of these gamma rays expected from a supernova with an 11 M_sun progenitor. The flux from neutron capture on protons exponentially decays on a timescale of 564 s, which is determined by neutron decay and capture on protons and 3He nuclei. The peak flux is 2.38x10^{-7}/cm^2/s for a supernova at a distance of 1 kpc. In contrast, the gamma-ray flux from positron annihilation follows the time evolution of the anti-nu_e luminosity and lasts for ~10 s. The peak flux in this case is 6.8x10^{-5}/cm^2/s for a supernova at a distance of 1 kpc. Detection of the above gamma-ray fluxes is beyond the capability of current instruments, and perhaps even those planned for the near future. However, if such fluxes can be detected, they not only constitute a new kind of signals that occur during the gap of several hours between the neutrino signals and the optical display of a supernova, but may also provide a useful probe of the conditions in the surface layers of the supernova progenitor.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑