论文标题
来自附近Starburst Galaxy NGC 253的宇宙射线253：低光度活性银核的影响
Cosmic rays from the nearby starburst galaxy NGC 253: the effect of a low luminosity active galactic nucleus
论文作者
论文摘要
NGC 253是雕塑家组附近的Starburst Galaxy，位于3.5 MPC的距离上，一些作者建议将其作为宇宙射线加速度的潜在位置，直到超高的能量。它的核区域被气体和灰尘掩盖了，这阻止了银河系是否与Starburst共存的超级质量黑洞。文献中已经提出了一些来源作为活性核的候选者。在这项工作中，我们旨在确定NGC 253核的超质量黑洞的存在可能对宇宙射线加速有可能。以此目的，我们将积聚流向推定的活性核进行建模，并通过黑洞发电机机制评估颗粒加速度的可行性。作为副产品，我们探讨了积聚流中非热颗粒对银河系高能发射的潜在贡献。我们发现，在三个最合理的核心候选核中，积聚流的发射会抑制黑洞发电机的机理。为了完全排除NGC 253中假定的核对宇宙射线加速度可能具有的影响，就需要更好地澄清核的真实性质。
NGC 253 is a nearby starburst galaxy in the Sculptor group located at a distance of 3.5 Mpc that has been suggested by some authors as a potential site for cosmic-ray acceleration up to ultra-high energies. Its nuclear region is heavily obscured by gas and dust, which prevents establishing whether or not the galaxy harbours a supermassive black hole coexisting with the starburst. Some sources have been proposed in the literature as candidates for an active nucleus. In this work, we aim at determining the implications that the presence of a supermassive black hole at the nucleus of NGC 253 might have on cosmic ray acceleration. With this aim, we model the accretion flow on to the putative active nucleus, and we evaluate the feasibility of particle acceleration by the black hole dynamo mechanism. As a by-product, we explore the potential contribution from non-thermal particles in the accretion flow to the high-energy emission of the galaxy. We found that in the three most plausible nucleus candidates, the emission of the accretion flow would inhibit the black hole dynamo mechanism. To rule out completely the influence that a putative nucleus in NGC 253 might have in cosmic-ray acceleration, a better clarification concerning the true nature of the nucleus is needed.
