Broadband X-Ray Spectral Analysis of the Double-nucleus Luminous Infrared Galaxy Mrk 463
Broadband X-Ray Spectral Analysis of the Double-nucleus Luminous Infrared Galaxy Mrk 463
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DOI：
10.3847/1538-4357/aabacb
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发表时间：
2018-03
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通讯作者：
S. Yamada;Y. Ueda;S. Oda;A. Tanimoto;M. Imanishi;Y. Terashima;C. Ricci
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作者：
S. Yamada;Y. Ueda;S. Oda;A. Tanimoto;M. Imanishi;Y. Terashima;C. Ricci
利用核光谱望远镜阵列（努斯塔）、Chandra和XMM-Newton对亮红外星系（LIRG）系统Mrk 463进行了宽带（0.4-70 keV）X射线光谱分析，该系统包含两个活动星系核（AGNs; Mrk 463 E和Mrk 463 W），间距为1.38 kpc。利用努斯塔探测其透射的大于10 keV的硬X射线连续谱，我们确认Mrk 463 E和Mrk 463 W具有内禀亮度分别为（1.6-2.2）× 1043和（0.5-0.6）× 1043 erg s−1（2-10 keV）的活动星系核，它们分别被8 × 1023和3 × 1023 cm−2的氢柱密度所遮蔽。两个核都显示出来自冷物质的强烈反射分量。Mrk 463 E的X射线（2-10 keV）与[O iv] 25.89 μm的光度比比正常Seyfert星系的光度比小10.5倍，表明内禀SED的X射线相对于UV光度是弱的。事实上，根据L′带（3.8 μm）、[O iv] 25.89 μm和[Ne v] 14.32 μm谱线估算的Mrk 463 E活动星系核的辐射热光度表明，辐射热光度与X射线光度之比很大，κ2-10 keV为110-410，埃丁顿比很大，λEdd为0.4-0.8。我们认为，合并引发了Mrk 463 E中黑洞的快速增长，该黑洞尚未被环核尘埃深埋。相比之下，Mrk 463 W的L′波段光度相对于X射线光度来说异常的小，这表明爱丁顿比很低（<10−3），它可能仍然处于合并驱动活动星系核活动的早期阶段。
We present a broadband (0.4–70 keV) X-ray spectral analysis of the luminous infrared galaxy (LIRG) system Mrk 463 observed with Nuclear Spectroscopic Telescope Array (NuSTAR), Chandra, and XMM-Newton, which contains double active galactic nuclei (AGNs; Mrk 463E and Mrk 463W) with a separation of ∼3.8 kpc. Detecting their transmitted hard X-ray >10 keV continua with NuSTAR, we confirm that Mrk 463E and Mrk 463W have AGNs with intrinsic luminosities of (1.6–2.2) × 1043 and (0.5–0.6) × 1043 erg s−1 (2–10 keV) obscured by hydrogen column densities of 8 × 1023 and 3 × 1023 cm−2, respectively. Both nuclei show strong reflection components from cold matter. The luminosity ratio between X-ray (2–10 keV) and [O iv] 25.89 μm of Mrk 463E is ∼5 times smaller than those of normal Seyfert galaxies, suggesting that the intrinsic SED is X-ray weak relative to the UV luminosity. In fact, the bolometric AGN luminosity of Mrk 463E estimated from L′-band (3.8 μm), [O iv] 25.89 μm, and [Ne v] 14.32 μm lines indicate a large bolometric-to-X-ray luminosity ratio, κ2–10 keV ≈ 110–410, and a high Eddington ratio, λEdd ∼ 0.4–0.8. We suggest that the merger triggered a rapid growth of the black hole in Mrk 463E, which is not yet deeply “buried” by circumnuclear dust. By contrast, the L′-band luminosity of Mrk 463W is unusually small relative to the X-ray luminosity, suggesting that the Eddington ratio is low (<10−3) and it might be still in an early phase of merger-driven AGN activity.