之前的研究显示水超脉泽辐射更倾向位于被物质严重遮掩的活动星系核中,因此,作者选择了一个活动星系核样本,开展水超脉泽的搜寻工作.该样本主要基于它们的中红外辐射特性(谱和颜色特性)而被证认为活动星系核,并由于被严重遮掩而未能在之前的光学观测中被证认.作者申请并获准应用德国Effelsberg 100 m口径望远镜,于2014年1月开展了水超脉泽的搜寻工作.观测结果显示只有几个源的谱存在可能的脉泽辐射,根据观测结果的噪声水平和这些星系的距离,作者估算了每个源的水脉泽辐射光度的上限值,这将对以后更高灵敏度的搜寻工作提供指导.
H20 megamasers prefer to be heavily obscured, even Compton-thick (absorbing column density lar- ger than 10-24 cm-2) AGN (active galaxy nuclei). Among all unambiguously identified bona-fide Compton-thick AGN, more than half of them have been detected with H20 megamaser emission. Previous H20 megamaser searching mostly focused on optical identified AGN, which was insensitive to the identification of heavily dust- obscured AGN. Recently, Middle-Infrared (MIR) data, including MIR emission lines, color criteria and color excess, were found to be quite an effective method to identify dust-obscured AGN. Here we report a pilot survey for H20 megamasers in a sample of MIR-identified AGN, which was missing in previous optical-identified AGNs.