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arXiv 0706.3485astro-ph
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我们应该在哪个壳层型信噪比中寻找来自p-p碰撞的伽马射线和中微子?

In which shell-type SNRs should we look for gamma-rays and neutrinos from p-p collisions?

Boaz Katz, Eli Waxman

摘要:

我们提出了一个简单的分析模型的各种贡献的非热发射从壳型信噪比,并表明,该模型的结果再现以及以前的详细计算的结果。我们表明,\geq 1 TeV的伽马射线发射从壳型SNR RX J1713.7-3946和RX J0852.0-4622是由CMB光子(可能是红外环境光子)的逆康普顿散射加速电子占主导地位。π介子衰变(由于质子-质子碰撞)只占观测到的辐射通量的一小部分(\lesssim 10^-2),因为假设贡献更大,则意味着非热射电和X射线同步辐射以及热X射线韧致辐射远远超过观测到的射电和X射线通量。π衰变主导\geq 1 TeV通量的模型通过假设极低的电子加速效率K_ep \lesssim 10^-4(K_ep是给定能量下被加速的电子数与被加速的质子数之比)来避免隐含的过量同步辐射(但不是隐含的过量热X射线韧致辐射)。我们认为,对附近星系信噪比的观测结果表明K_ep \gtrsim 10^-3的下限,因此排除了K_ep值\lesssim 10^-4的可能性(假设信噪比具有共同的典型K_ep值)。这表明,与强的非热X射线发射相比,具有强的热X射线发射的SNR更适合于搜索质子-质子碰撞产生的伽马射线和中微子。特别是,它表明,从上述信噪比的中微子流量可能太低,无法检测到现有的和计划中的中微子天文台(摘要)。

英文摘要:

We present a simple analytic model for the various contributions to the non-thermal emission from shell type SNRs, and show that this model's results reproduce well the results of previous detailed calculations. We show that the \geq 1 TeV gamma ray emission from the shell type SNRs RX J1713.7-3946 and RX J0852.0-4622 is dominated by inverse-Compton scattering of CMB photons (and possibly infra-red ambient photons) by accelerated electrons. Pion decay (due to proton-proton collisions) is shown to account for only a small fraction, \lesssim10^-2, of the observed flux, as assuming a larger fractional contribution would imply nonthermal radio and X-ray synchrotron emission and thermal X-ray Bremsstrahlung emission that far exceed the observed radio and X-ray fluxes. Models where pion decay dominates the \geq 1 TeV flux avoid the implied excessive synchrotron emission (but not the implied excessive thermal X-ray Bremsstrahlung emission) by assuming an extremely low efficiency of electron acceleration, K_ep \lesssim 10^-4 (K_ep is the ratio of the number of accelerated electrons and the number of accelerated protons at a given energy). We argue that observations of SNRs in nearby galaxies imply a lower limit of K_ep \gtrsim 10^-3, and thus rule out K_ep values \lesssim 10^-4 (assuming that SNRs share a common typical value of K_ep). It is suggested that SNRs with strong thermal X-ray emission, rather than strong non-thermal X-ray emission, are more suitable candidates for searches of gamma rays and neutrinos resulting from proton-proton collisions. In particular, it is shown that the neutrino flux from the SNRs above is probably too low to be detected by current and planned neutrino observatories (Abridged).

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。

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