BAT AGN Spectroscopic Survey – III. An observed link between AGN Eddington ratio and narrow-emission-line ratios
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Archivos
Fecha
2016-09
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
OXFORD UNIV PRESS
Nombre de Curso
Licencia CC
Licencia CC
Resumen
We investigate the observed relationship between black hole mass (M-BH), bolometric luminosity (L-bol) and Eddington ratio (lambda(Edd)) with optical emission-line ratios ([N II] lambda 6583/H alpha, [S II] lambda lambda 6716, 6731/H alpha, [O I] lambda 6300/H alpha, [O III] lambda 5007/H beta, [Ne III] lambda 3869/H beta and He II lambda 4686/H beta) of hard X-ray-selected active galactic nuclei (AGN) from the BAT AGN Spectroscopic Survey. We show that the [N II] lambda 6583/H alpha ratio exhibits a significant correlation with lambda(Edd) (R-Pear = -0.44, p-value = 3 x 10(-13), sigma = 0.28 dex), and the correlation is not solely driven by M-BH or L-bol. The observed correlation between [N II] lambda 6583/H alpha ratio and M-BH is stronger than the correlation with L-bol, but both are weaker than the lambda(Edd) correlation. This implies that the large-scale narrow lines of AGN host galaxies carry information about the accretion state of the AGN central engine. We propose that [N II] lambda 6583/H alpha is a useful indicator of Eddington ratio with 0.6 dex of rms scatter, and that it can be used to measure lambda(Edd) and thus M-BH from the measured L-bol, even for high-redshift obscured AGN. We briefly discuss possible physical mechanisms behind this correlation, such as the mass-metallicity relation, X-ray heating, and radiatively driven outflows.
Notas
Indexación: Web Of Science; Scopus.
Palabras clave
Black hole physics, Galaxies: active, Galaxies: nuclei, Quasars: general
Citación
Mon Not R Astron Soc (2017) 464 (2): 1466-1473