本文介绍了用XMM-Newton EPIC相机对超亮红外星系(HLIRG)IRAS 00182- 7112(F00183- 7111)的X射线观测结果。揭示了与原子核重合的发光硬X射线源,以及较弱的软X射线发射,该发射可能会从硬X射线中延伸或抵消。EPIC光谱是非常平坦的,并显示了Fe K $α$发射具有非常高的等效宽度:这两个都是一个埋,康普顿-厚AGN,这是看到只有在散射光的典型特征。也许该光谱最显著的特征是Fe K $α$线的能量是类He铁的能量,这使得IRAS 00182- 7112成为已知的第一个被电离的康普顿厚反射控制的隐藏活动星系核。采取适当的辐射热修正,我们发现,这个活动星系核可以很容易地主导FIR能量。核反射光谱是通过一个相对冷的吸收体看到的,其柱密度与斯皮策最近的观测结果一致。软X射线发射,可能是热的性质,并与恒星形成活动有关,被认为是未被吸收的。软X射线和弱PAH特征都给出了恒星形成速率$\sim 300 M_{\odot}$ yr $^{-1}$的估计,不足以为远红外辐射提供能量,也支持了这一HLIRG是活动星系核主导的观点。
英文摘要:
We present X-ray observations of the Hyperluminous Infrared Galaxy (HLIRG) IRAS 00182--7112 (F00183--7111) obtained using the XMM-Newton EPIC camera. A luminous hard X-ray source co-incident with the nucleus is revealed, along with weaker soft X-ray emission which may be extended or offset from the hard. The EPIC spectrum is extremely flat and shows Fe K$α$ emission with very high equivalent width: both are typical characteristics of a buried, Compton--thick AGN which is seen only in scattered light. Perhaps the most remarkable characteristic of the spectrum is that the Fe K$α$ line energy is that of He-like iron, making IRAS 00182--7112 the first hidden AGN known to be dominated by ionized, Compton thick reflection. Taking an appropriate bolometric correction we find that this AGN could easily dominate the FIR energetics. The nuclear reflection spectrum is seen through a relatively cold absorber with column density consistent with recent Spitzer observations. The soft X-ray emission, which may be thermal in nature and associated with star-forming activity, is seen unabsorbed. The soft X-rays and weak PAH features both give estimates of the star formation rate $\sim 300 M_{\odot}$ yr$^{-1}$, insufficient to power the FIR emission and supportive of the idea that this HLIRG is AGN-dominated.
BeppoSAX uncovers a type-2 QSO in the hyperluminous infrared galaxy IRAS 09104+4109
我们用BeppoSAX研究了红外发光星系IRAS 09104+4109在0.1至80 keV的非常宽的X射线波段。我们的观察表明,在低于8千电子伏的能量,我们归因于自由的自由发射从集群内(IC)周围的源等离子体的热分量的主导地位。在10千电子伏以上,我们发现的证据,存在过剩的流量相对于自由自由IC等离子体发射。这一点,加上在$\sim 6.4$ keV的中性铁线的边缘检测,给出了一个强烈的迹象,深埋在源内的活动星系核的存在。该成分最好用强吸收(N_H > 5 × 10^{24} cm^{-2})幂律加上未吸收反射光谱(0.15<R<0.3)来模拟,这也是冷铁谱线的原因。该活动星系核未被吸收的宽带(2-100 keV)X射线辐射为2.5 × 10 $^{46} erg/s, well within the range of quasar luminosities. Our results indicate that IRAS 09104+4109 is indeed the prototype of a rare class of sources, the luminous type-2 QSOs. The association of this source with a huge cooling-flow of $ \sim 1000 M_ \odot $。X射线数据表明,这种极…
On the lack of cold dust in IRAS P09104+4109 and IRAS F15307+3252 -- their spectral energy distributions and implications for finding dusty AGNs at high redshift
High-Resolution Molecular Line Observations of the Environment of the Class 0 Source B1-IRS
本文介绍了在距恒星形成区B1-IRS(IRAS 03301+3057)1cm处,用角分辨率~ 5”(=1750 AU)的VLA观测到的NH_3、CCS和H_2 O脉泽辐射。CCS排放在中心源周围分布成三个团。这些团块呈现出从红移到蓝移的速度梯度,朝向B1-IRS,可能是由于与嵌入的原恒星流出的相互作用。外流和它的动力源是由一个反射星云和一个相关的红外点源在2 MASS K波段图像检测跟踪。我们发现,这个红外点源与水脉泽发射分布在一个细长的结构(约450 AU大小)沿反射星云的主轴和跟踪该地区的流出基地。氨排放与CCS有着空间上的相关性。这是第一次在具有如此高的角分辨率的恒星形成区域中观察到这种关系,并说明了小空间尺度上依赖于时间的化学的重要性。与其他恒星形成区相比,CCS相对于氨的丰度较大,这表明B1-IRS天体非常年轻(<10 E +5年)。我们建议CCS丰度通过冲击诱导化学增强的可能性。