射电强窄线赛弗特1型星系辐射性质

项目名称： 射电强窄线赛弗特1型星系辐射性质

项目编号： No.11473054

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 顾敏峰

作者单位： 中国科学院上海天文台

项目金额： 95万元

中文摘要： 窄线赛弗特1型星系黑洞质量较小，吸积率较高，可能是年轻活动星系核，其中大约7%为射电强源，但其射电性质并不统一，有些源与致密陡谱源相似，另一些源与耀变体相似。VLBI观测，和探测到的伽马射线辐射证明相对论性喷流的存在，但目前对它们的喷流性质还知之甚少。射电强窄线赛弗特1型星系由于黑洞质量较小，吸积率较高，因此与典型射电强活动星系核有很大差别，为喷流形成机制的研究提供了新的观测依据。本项目将结合射电高分辨率观测，伽马射线辐射研究，多波段数据模型拟合，光变监测，研究：（1）大样本射电强窄线赛弗特1型星系致密射电结构和性质，喷流形成物理条件；（2）伽马射线辐射性质，产生机制；（3）射电强窄线赛弗特1型星系与致密陡谱源、耀变体之间关系，它们在活动星系核整体框架下的位置。研究结果将有助于深入探索活动星系核喷流形成机制。

中文关键词： 活动星系核；辐射机制；射电天文；多波段；伽玛射线

英文摘要： Narrow line Seyfert 1 galaxies (NLS1s) are often thought to be young active galactic nuclei (AGNs) with relatively small black hole masses and high accretion rates. About 7% NLS1s are radio-loud, however, radio-loud NLS1s (RLNLS1s) are inhomogeneous in their radio properties, with some associated with compact steep-spectrum (CSS) radio sources, and others resemble to blazars. Relativistic jets were shown to exist in a few RLNLS1s based on VLBI observations and confirmed by the gamma-ray flaring of some of them. These properties are unexpected, in light of the low black hole masses, high accretion rates, which however provide observational evidence of jet formation under such conditions. Up to now, little has been known on the jet properties of RLNLS1s. In this project, by combining VLBI radio observations with the investigations on gamma-ray emission, SED model fit, and variability monitoring, we will investigate: (1) the compact radio structure and properties, and the physical conditions of jet formation for a large sample of RLNLS1s; (2) the properties and mechanism of gamma-ray emission; (3) the relationship between RLNLS1s and CSSs, and blazars, and also the place of RLNLS1s in overall AGNs populations. The results will be great helpful for us to study deeply the jet formation in AGNs.

英文关键词： Active galactic nuclei;radiation mechanism;radio astronomy;multi wavelength;gamma-ray