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arXiv 1503.08295astro-ph.GA
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3C 57是一个非典型的射电强类星体:射电强/射电静二分法的意义

3C 57 as an Atypical Radio-Loud Quasar: Implications for the Radio-Loud/Radio-Quiet Dichotomy

J. W. Sulentic, M. A. Martínez-Carballo, P. Marziani, A. del Olmo, G. M. Stirpe, S. Zamfir, I. Plauchu-Frayn

摘要:

波瓣主导的射电强(LD RL)类星体在4D特征向量1(4DE 1)参数空间中占据了一个有限的域,这意味着与大多数射电安静(RQ)类星体相比,该子类的几何/物理/运动学受到限制。我们讨论如何这个限制域的LD RL父母人口支持的概念,RQ-RL二分法之间的类型1源。3C 57是一个非典型的RL类星体,它既有不确定的射电形态,又位于RL类星体稀少的4DE 1空间区域。我们提出了新的无线电流量和光学光谱措施,旨在验证其非典型的光学/紫外光谱行为,并澄清其无线电结构。前者证实了3C 57脱离了4DE 1类星体的“主序”,具有极强的光学Fe Ⅱ发射(R_{FeII} ~ 1)和大的CIV 1549剖面蓝移(~ -1500 km/s)。这些参数值是典型的极端人口A源,几乎总是RQ。新的无线电测量表明,在50多年的时间尺度上,没有证据表明通量变化与核心主导形态的紧凑陡谱(CSS或年轻LD)一致。在4DE 1背景下,LD RL通常是低L/ L_{Edd}类星体,我们认为3C 57是一个演化的RL类星体(即大的黑洞质量)经历了一个主要的吸积事件,导致由强烈的FeII发射反映的复兴,可能表明显着的重金属富集,一个低红移源的高辐射热光度和由此产生的异常高的爱丁顿比导致了非典型的CIV 1549。

英文摘要:

Lobe-dominated radio-loud (LD RL) quasars occupy a restricted domain in the 4D Eigenvector 1 (4DE1) parameter space which implies restricted geometry/physics/kinematics for this subclass compared to the radio-quiet (RQ) majority of quasars. We discuss how this restricted domain for the LD RL parent population supports the notion for a RQ-RL dichotomy among Type 1 sources. 3C 57 is an atypical RL quasar that shows both uncertain radio morphology and falls in a region of 4DE1 space where RL quasars are rare. We present new radio flux and optical spectroscopic measures designed to verify its atypical optical/UV spectroscopic behaviour and clarify its radio structure. The former data confirms that 3C 57 falls off the 4DE1 quasar "main sequence" with both extreme optical FeII emission (R_{FeII} ~ 1) and a large CIV 1549 profile blueshift (~ -1500 km/s). These parameter values are typical of extreme Population A sources which are almost always RQ. New radio measures show no evidence for flux change over a 50+ year timescale consistent with compact steep-spectrum (CSS or young LD) over core-dominated morphology. In the 4DE1 context where LD RL are usually low L/L_{Edd} quasars we suggest that 3C 57 is an evolved RL quasar (i.e. large Black Hole mass) undergoing a major accretion event leading to a rejuvenation reflected by strong FeII emission, perhaps indicating significant heavy metal enrichment, high bolometric luminosity for a low redshift source and resultant unusually high Eddington ratio giving rise to the atypical CIV 1549.

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