On the central black hole mass in Mkn 501
On the central black hole mass in Mkn 501
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DOI：
10.1051/0004-6361:20021482
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发表时间：
2002-10
影响因子：
6.5
通讯作者：
F. Rieger;K. Mannheim
中科院分区：
文献类型：
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作者：
F. Rieger;K. Mannheim
我们基于（i）对宿主星系的观测，（ii）高能（HE）发射机制，以及（iii）黑洞（BH）双星系统对射束辐射的调制，分析了 Mkn 501 中中心黑洞质量估计之间的明显不一致。虽然方法 (i) 似乎意味着中心质量 $\ga$ $ 5\times 10^8\, M_{\odot}$，但方法 (ii) 表明 BH 质量小于 $\simeq$ $ 6 \times 10^7\, M_{\odot}$。我们批判性地讨论从 (i) 推断出的估计，表明当前的不确定性可能允许中心质量低至 $\simeq$(2–$3)\times 10^8\,M_{\odot}$。我们证明，在这种情况下，通过假设二元 BH 系统，估计 (i) 和 (ii) 可能会一致，其中主导 HE 排放的射流源自质量较小的（次级）BH，如方法 (iii) 所示。另一方面，如果 Mkn 501 实际上具有 $10^9\, M_{\odot}$ 量级的高中心 BH 质量，则在几个 HE 发射模型的背景下似乎需要改变基本假设。我们表明，在这种情况下，如果主导发射的射流从更大的（初级）黑洞中出现，并且如果双星演化经历了超爱丁顿吸积和/或降低的转换效率阶段，那么（iii）之后的双星场景仍然是可能的。
We analyse the apparent disagreement between the mass estimates of the central black hole(s) in Mkn 501 based on (i) the observations of the host galaxy, (ii) the high energy (HE) emission mechanism, and (iii) the modulation of the beamed radiation by a black hole (BH) binary system. While method (i) seems to imply a central mass $\ga$ $ 5\times 10^8\, M_{\odot}$, method (ii) suggests a BH mass less than $\simeq$ $ 6 \times 10^7\, M_{\odot}$. We critically discuss the estimates inferred from (i) showing that current uncertainties may permit a central mass as low as $\simeq$(2–$3)\times 10^8\,M_{\odot}$. We demonstrate that in this case the estimates (i) and (ii) might be brought into agreement by assuming a binary BH system where the jet dominating the HE emission originates from the less massive (secondary) BH as suggested by method (iii). On the other hand, if Mkn 501 has in fact a high central BH mass of order $10^9\, M_{\odot}$, a change of fundamental assumptions seems to be required in the context of several HE emission models. We show, that in this case a binary scenario following (iii) may be still possible if the jet which dominates the emission emerges from the more massive (primary) BH and if the binary evolution passes through phases of super-Eddington accretion and/or decreased conversion efficiency.