Radiative Inefficiency in LINER Nuclei: Evidence for ADAF-like Accretion

Authors: Efe Yenice, Ahmet Selim Çevirgen

NGC 1097 (Source: Wikipedia)

Abstract

We present a brief analysis of the radiative properties of LINER nuclei, focusing on the physical origin of their low luminosity. Compared to classical active galactic nuclei, many LINERs, including NGC 1097, exhibit low Eddington ratios, weak or absent UV continua, and relatively hard X-ray spectra, indicating a fundamentally different accretion regime. These observational characteristics are consistent with radiatively inefficient accretion flows, in particular the Advection Dominated Accretion Flow (ADAF) model. In this regime, a significant fraction of the accretion energy may be advected inward or carried away by outflows rather than radiated, helping to explain the suppressed optical/UV emission and X ray-dominated spectral energy distribution. We conclude that some LINER nuclei can be interpreted as low-efficiency accretion states of supermassive black holes, distinct from standard thin-disk AGN.

Read online

Please click here to read this article online.

Download PDF

Lıner_adaf (2).pdf

Download PDF • 233KB

References

[1]  Nemmen, R. S., Storchi-Bergmann, T., Yuan, F., Eracleous, M., Terashima, Y., & Wilson, A. S. (2006). Radiatively inefficient accretion flow in the nucleus of NGC 1097. The Astrophysical Journal, 643(1), 652-659. https://doi.org/10.1086/500571.

[2] Ho, L. C. (2008). Nuclear activity in nearby galaxies. Annual Review of Astronomy and Astrophysics, 46, 475-539. https://doi.org/10.1146/annurev.astro.45.051806.110546.

[3] Narayan, R., & Yi, I. (1995). Advection-dominated accretion: Under fed black holes and neutron stars. The Astrophysical Journal, 452, 710. https://doi.org/10.1086/176343.

[4] Narayan, R., & McClintock, J. E. (2008). Advection-dominated accretion and the black hole event horizon. New Astronomy Reviews, 51(10–12), 733-751. https://doi.org/10.1016/j.newar.2008.03.002.

[5] Terashima, Y., & Wilson, A. S. (2003). Chandra Snapshot Observations of Low-Luminosity Active Galactic Nuclei with a Compact Radio Source. The Astrophysical Journal, 583(1), 145-158. https://doi.org/10.1086/345339.

[6] Fabbiano, G. (2006). Populations of X-ray sources in galaxies. Annual Review of Astronomy and Astrophysics, 44, 323-366. https://doi.org/10.1146/annurev.astro.44.051905.092519.