2004/03/18 by M. Nikołajuk, M. Nikolajuk, I. E. Papadakis +1 · 1 citation
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2004.07829.x
published as Mon.Not.Roy.Astron.Soc. 350 (2004) L26 · 5 pages, 1 figure, 1 table, accepted for publication in MNRAS Letter. Added minor change on page 5 - corrected mistake (1/T < nu => 1/T > nu)
arxiv created 2004/03/18 · openalex publication_date 2004/04/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29
We propose a new method of estimation of the black hole masses in active galactic nuclei (AGN) based on the normalized excess variance, σ2nxs. We derive a relation between σ2nxs, the length of the observation, T, the light-curve bin size, Δt, and the black hole mass, assuming that (i) the power spectrum above the high-frequency break, νbf, has a slope of −2, (ii) the high-frequency break scales with black hole mass, (iii) the power-spectrum amplitude (in frequency–power space) is universal and (iv) σ2nxs is calculated from observations of length T < 1/νbf. Values of black hole masses in AGN obtained with this method are consistent with estimates based on other techniques such as reverberation mapping or the MBH–stellar velocity dispersion relation. The method is formally equivalent to methods based on power spectrum scaling with mass, but the use of σ2nxs has the big advantage of being applicable to relatively low-quality data.