arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1305.2138astro-ph.HE
收藏

从远距离硬谱Blazar的极高能Gamma-Ray辐射中解开强子和轻子级联方案

Disentangling Hadronic and Leptonic Cascade Scenarios from the Very-High-Energy Gamma-Ray Emission of Distant Hard-Spectrum Blazars

Hajime Takami, Kohta Murase, Charles D. Dermer

摘要:

最近来自\emph{Fermi}大面积望远镜的数据揭示了大约十几个遥远的硬光谱耀变体,它们具有与它们相关的极高能量(VHE; $\gtrsim 100$ GeV)光子,但其中大多数尚未被成像大气切伦科夫望远镜探测到。这些高能伽马射线光谱中的大多数,像其他极端高频峰值BL Lac天体的光谱一样,可以很好地解释为在源处发射的伽马射线或由超高能宇宙射线引起的级联,正如我们专门为KUV 00311 $-$ 1938所展示的那样。我们考虑了计划中的切伦科夫望远镜阵列(CTA)检测VHE源的前景,并展示了它如何通过测量样本中具有$z \lesssim 1$的几个光源的$\sim 500$ GeV以上的积分通量(取决于源红移)来区分这两种情况。超高能宇宙射线起源的强有力证据可以从CTA的VHE观测中获得。根据红移,如果经常引用的KUV 00311-1938($z = 0.61$)的红移是可信的,那么初步的H.E.S.S.数据支持由超高能宇宙射线引起的级联。硬光谱耀变体的精确红移测量对于这项研究至关重要。

英文摘要:

Recent data from the \emph{Fermi} Large Area Telescope have revealed about a dozen distant hard-spectrum blazars that have very-high-energy (VHE; $\gtrsim 100$ GeV) photons associated with them, but most of them have not yet been detected by imaging atmospheric Cherenkov telescopes. Most of these high-energy gamma-ray spectra, like those of other extreme high-frequency peaked BL Lac objects, can be well explained either by gamma rays emitted at the source or by cascades induced by ultra-high-energy cosmic rays, as we show specifically for KUV 00311$-$1938. We consider the prospects for detection of the VHE sources by the planned Cherenkov Telescope Array (CTA) and show how it can distinguish the two scenarios by measuring the integrated flux above $\sim 500$ GeV (depending on source redshift) for several luminous sources with $z \lesssim 1$ in the sample. Strong evidence for the origin of ultra-high-energy cosmic rays could be obtained from VHE observations with CTA. Depending on redshift, if the often quoted redshift of KUV 00311-1938 ($z = 0.61$) is believed, preliminary H.E.S.S. data favor cascades induced by ultra-high-energy cosmic rays. Accurate redshift measurements of hard-spectrum blazars are essential for this study.

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。

↑