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arXiv · 1906.04179

An observational link between AGN Eddington ratio and [NII]{\lambda}6583/Ha at 0.6<z<1.7

Kyuseok Oh·Yoshihiro Ueda·Masayuki Akiyama·Hyewon Suh·Michael J. Koss·Daichi Kashino·Günther Hasinger
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Abstract

We present an observed relationship between Eddington ratio ({\lambda}Edd) and optical narrow-emission-line ratio ([N II]{\lambda}6583/H{\alpha}) of X-ray-selected broad-line active galactic nuclei (AGN) at 0.6 < z < 1.7. We use 27 near-infrared spectra from the Fiber Multi-Object Spectrograph along with 26 sources from the literature. We show that the {\lambda}Edd and [N II]{\lambda}6583/H{\alpha} ratio at 0.6 < z < 1.7 exhibits a similar anti-correlation distribution of {\lambda}Edd-[N II]{\lambda}6583/H{\alpha} as has been found for local ( = 0.036), ultra-hard X-ray selected AGN. The observed distribution implies that there is a consistent relationship from local to z \sim 1.7 which corresponds from the present time to 4 Gyr old. Further study of high redshift low Eddington ratio AGN (log{\lambda}Edd < -2) is necessary to determine fully whether the {\lambda}Edd-[N II]{\lambda}6583/H{\alpha} anti-correlation still holds in high-redshift AGN at low Eddington ratios.

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Kyuseok Oh, Yoshihiro Ueda, Masayuki Akiyama, Hyewon Suh, Michael J. Koss, Daichi Kashino, Günther Hasinger. 2019-06-10. An observational link between AGN Eddington ratio and [NII]{\lambda}6583/Ha at 0.6<z<1.7. https://doi.org/10.3847/1538-4357%2Fab288b

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