论文标题
用ATCA和Vlass观察到的窄线seyfert的无线电光谱
Radio spectra of narrow-line Seyfert 1 galaxies observed with ATCA and VLASS
论文作者
论文摘要
我们介绍了29个无线电定价（RQ）样品和三个窄线seyfert 1星系（NLS1S）样品的无线电光谱分析，该样品在5.5 GHz和9.0 GHz的澳大利亚望远镜紧凑型阵列中检测到了29个窄线1个星系（NLS1S）。样品以l_bol/l_edd> 0.15为特征。 29 RQ NLS1中25个的无线电坡度陡峭（Alpha_5.5-9.0 <-0.5），如较早的RQ High L_BOL/L_EDD AGN的早期研究所示。这种陡峭的无线电发射可能与AGN驱动的流出有关，这可能在高L_BOL/L_EDD AGN中更为普遍。在三个RL NLS1中的两个中，无线电斜率是平坦的或倒置的（Alpha_5.5-9.0> -0.5），表明具有紧凑的光学厚度来源，可能是相对论的射流。还编制了3.0 GHz，1.4 GHz和0.843 GHz的档案数据，在三个或更多频段中检测到17个NLS1的样本。在九个对象中，无线电光谱以较低的频率变平，中位斜率为alpha_5.5-9.0 = -1.21 +/- 0.17，直至Alpha_3.0-5.5 = -0.97 +/- 0.27，并触及Alpha_1.1.4-3.0 = -0.63 +/-0.16 +/-0.16。抛物线拟合表明〜1 GHz的光谱转换率为中间，这意味着在源中的同步体自我吸收，其大小仅为1 PC，可能是紧凑的风或弱喷气机。两个物体显示出在3 GHz或5 GHz上方的Alpha <-2的显着光谱陡峭，这可能表明从过去的几年到几十年前，从过去的无线电发射等离子体发射出来的遗物发射。最后，两个对象呈现一个与星形成活性一致的单光谱斜率。
We present radio spectral analyses for a sample of 29 radio-quiet (RQ) and three radio-loud (RL) narrow-line Seyfert 1 galaxies (NLS1s) detected with the Australia Telescope Compact Array at both 5.5 GHz and 9.0 GHz. The sample is characterized by L_bol/L_Edd > 0.15. The radio slopes in 25 of the 29 RQ NLS1s are steep (alpha_5.5-9.0 < -0.5), as found in earlier studies of RQ high L_bol/L_Edd AGN. This steep radio emission may be related to AGN-driven outflows, which are likely more prevalent in high L_bol/L_Edd AGN. In two of the three RL NLS1s, the radio slopes are flat or inverted (alpha_5.5-9.0 > -0.5), indicating a compact optically-thick source, likely a relativistic jet. Archival data at 3.0 GHz, 1.4 GHz, and 0.843 GHz are also compiled, yielding a sample of 17 NLS1s detected in three bands or more. In nine objects, the radio spectra flatten at lower frequencies, with median slopes of alpha_5.5-9.0 = -1.21 +/- 0.17, flattening to alpha_3.0-5.5 = -0.97 +/- 0.27, and to alpha_1.4-3.0 = -0.63 +/- 0.16. A parabolic fit suggests a median spectral turnover of ~ 1 GHz, which implies synchrotron self-absorption in a source with a size of only a fraction of 1 pc, possibly a compact wind or a weak jet. Two objects show significant spectral steepening to alpha < -2 above 3 GHz or 5 GHz, which may suggest relic emission from past ejection of radio emitting plasma, of the order of a few years to a few decades ago. Finally, two objects present a single spectral slope consistent with star-forming activity.
