APM 08279+5255: An Ultraluminous Broad Absorption Line Quasar at a Redshift z = 3.87
APM 08279+5255: An Ultraluminous Broad Absorption Line Quasar at a Redshift z = 3.87
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DOI：
10.1086/306213
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发表时间：
1998-06
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影响因子：
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通讯作者：
M. Irwin;R. Ibata;G. Lewis;E. Totten
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文献类型：
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作者：
M. Irwin;R. Ibata;G. Lewis;E. Totten
我们报告了一个高亮度的宽吸收线类星体的发现，其红移为z = 3.87，与IRAS暗源目录源F08279+5255的位置在1“以内重合。类星体和IRAS源的偶然对准是极不可能的，我们认为光学和远红外通量是同一物体的不同表现。APM 08279+5255在R波段的星等为15.2等，在IRAS 60 μm波段的通量为0.51 Jy，它是（显然）已知的本征亮度最高的天体，LBol约为5 × 1015 L。光学CCD测光的系统，在良好的看到，表明该系统是轻微拉长的证据。虽然这些数据是一致的叠加类星体上的一个非常明亮的星系，我们认为，更可能的情况是，光学图像意味着存在两个未解决的点源。这样的配置表明，引力透镜可能在放大系统的内在性质方面发挥重要作用。两个离散源的点扩散函数拟合给出了~0.“4的分离和~1.1的强度比。类星体的光谱清楚地揭示了三个潜在的透镜星系的存在，在z = 1.18和z = 1.81的Mg II吸收系统，以及在z = 3.07的阻尼Lyα吸收系统。此外，还没有看到，透镜星系也可能存在。我们估计光学元件的总放大率为1040，但由于发射区的规模较大，预计红外放大率会明显降低。即使保守地假设所有波长都被放大了40倍，APM 08279+5255仍然拥有1014 L的惊人光度，这表明它属于少数但重要的高红移超亮天体，具有丰富的红外辐射。
We report on the discovery of a highly luminous, broad absorption line quasar at a redshift of z = 3.87, which is positionally coincident, within 1'', with the IRAS Faint Source Catalog source F08279+5255. A chance alignment of the quasar and the IRAS source is extremely unlikely, and we argue that the optical and far-infrared flux are different manifestations of the same object. With an R-band magnitude of 15.2 and an IRAS 60 μm flux of 0.51 Jy, APM 08279+5255 is (apparently) easily the most intrinsically luminous object known, with LBol ~ 5 × 1015 L☉. Optical CCD photometry of the system, taken in good seeing, shows evidence that the system is slightly elongated. Although these data are consistent with the superposition of the quasar on a vastly luminous galaxy, we argue that a more likely scenario is that the optical image implies the presence of two unresolved point sources. Such a configuration suggests that gravitational lensing may play a significant role in amplifying the intrinsic properties of the system. Point-spread function fitting of two discrete sources gives a separation of ~0.″4 and an intensity ratio ~1.1. The optical spectrum of the quasar clearly reveals the presence of three potential lensing galaxies, Mg II absorption systems at z = 1.18 and z = 1.81, and a damped Lyα absorption system at z = 3.07. Additional, as yet unseen, lensing galaxies may also be present. We estimate the total amplification of the optical component to be ≈ 40 but, owing to the larger scale of the emitting region, would expect the infrared amplification to be significantly less. Even making the conservative assumption that all wavelengths are amplified by a factor 40, APM 08279+5255 still possesses a phenomenal luminosity of ≳1014 L☉, indicating that it belongs to a small but significant population of high-redshift, hyperluminous objects with copious infrared emission.