The LoTSS view of radio AGN in the local Universe
The LoTSS view of radio AGN in the local Universe
复制标题
本地宇宙中无线电 AGN 的 LoTSS 视图
DOI：
--
复制
发表时间：
2018
影响因子：
6.5
通讯作者：
A. Saxena
中科院分区：
文献类型：
--
作者：
J. Sabater;P. Best;M. Hardcastle;T. Shimwell;C. Tasse;W. Williams;M. Brüggen;R. Cochrane;J. Croston;F. Gasperin;K. Duncan;G. Gürkan;A. Mechev;L. Morabito;I. Prandoni;H. Röttgering;Daniel J. B. Smith;J. Harwood;B. Mingo;S. Mooney;A. Saxena
本文通过对LOFAR两米巡天（LoTSS）第一次数据发布（DR 1）与斯隆数字巡天（SDSS）DR 7主星系光谱样本的交叉比较，对本地射电源群进行了研究。LoTSS DR 1提供了424平方度天空的深层数据（150 MHz时的均方根噪声中值为71 μJy），足以探测该天空区域的10615个SDSS星系（32%）。本文提出了一种从星星形成（SF）辐射源中精确分离活动星系核（AGN）的改进方法，得到了2121个局域（z <0.3）射电AGN样本。 分别导出了射电活动星系核和SF星系的局域150 MHz光度函数，在1.4 GHz处与以前的研究结果吻合良好，表明所提出的分离方法是稳健的。射电活动星系核活动的普遍性被证实与恒星质量和黑洞质量有很强的依赖关系，在L150MHz ≥ 1021 W Hz−1的射电活动星系核活动中，最大质量的星系（> 1011M）的比例明显达到100%;因此，最大质量的星系总是在某种程度上被打开。 这些结果使得我们可以探测大质量星系的完整的爱丁顿尺度吸积率分布（占空比的代表），并且发现这个吸积率在Lmech/LEdd = 10−5处达到峰值。 超过50%的能量是在最高吸积率（Lmech/LEdd> 10−2.5）下的≤ 2%的时间内释放的。 恒星质量被证明是比黑洞质量更重要的无线电活动星系核活动的驱动力，这表明燃料气体和周围的晕之间可能存在联系。这一结果是符合模型，这些无线电活动星系核是必不可少的维持淬火状态的星系中心的热气晕。
This paper presents a study of the local radio source population, by cross-comparing the data from the first data release (DR1) of the LOFAR Two-Metre Sky Survey (LoTSS) with the Sloan Digital Sky Survey (SDSS) DR7 main galaxy spectroscopic sample. The LoTSS DR1 provides deep data (median rms noise of 71 μJy at 150 MHz) over 424 square degrees of sky, which is sufficient to detect 10 615 (32 per cent) of the SDSS galaxies over this sky area. An improved method to separate active galactic nuclei (AGN) accurately from sources with radio emission powered by star formation (SF) is developed and applied, leading to a sample of 2121 local (z < 0.3) radio AGN. The local 150 MHz luminosity function is derived for radio AGN and SF galaxies separately, and the good agreement with previous studies at 1.4 GHz suggests that the separation method presented is robust. The prevalence of radio AGN activity is confirmed to show a strong dependence on both stellar and black hole masses, remarkably reaching a fraction of 100 per cent of the most massive galaxies (> 1011 M⊙) displaying radio-AGN activity with L150 MHz ≥ 1021 W Hz−1; thus, the most massive galaxies are always switched on at some level. The results allow the full Eddington-scaled accretion rate distribution (a proxy for the duty cycle) to be probed for massive galaxies, and this accretion rate is found to peak at Lmech/LEdd ≈ 10−5. More than 50 per cent of the energy is released during the ≤2 per cent of the time spent at the highest accretion rates, Lmech/LEdd > 10−2.5. Stellar mass is shown to be a more important driver of radio-AGN activity than black hole mass, suggesting a possible connection between the fuelling gas and the surrounding halo. This result is in line with models in which these radio AGN are essential for maintaining the quenched state of galaxies at the centres of hot gas haloes.
影响因子：
6.5
作者：
T. Shimwell;H. Röttgering;P. Best;W. Williams;T. J. Dijkema;F. Gasperin;M. Hardcastle;G. Heald
通讯作者：
T. Shimwell;H. Röttgering;P. Best;W. Williams;T. J. Dijkema;F. Gasperin;M. Hardcastle;G. Heald
影响因子：
6.5
作者：
van Haarlem, M. P.;Wise, M. W.;van Zwieten, J.
通讯作者：
van Zwieten, J.