Evidence for an Optical Low-frequency Quasi-periodic Oscillation in the Kepler Light Curve of an Active Galaxy
Abstract
We report evidence for a quasi-periodic oscillation (QPO) in the optical light curve of KIC 9650712, a narrow-line Seyfert 1 galaxy in the original Kepler field. After the development and application of a pipeline for Kepler data specific to active galactic nuclei (AGNs), one of our sample of 21 AGNs selected by infrared photometry and X-ray flux demonstrates a peak in the power spectrum at log ν = -6.58 Hz, corresponding to a temporal period of t = 44 days. We note that although the power spectrum is well fit by a model consisting of a Lorentzian and a single power law, alternative continuum models cannot be ruled out. From optical spectroscopy, we measure the black hole mass of this AGN as log (M BH/M ⊙) = 8.17. We find that this frequency lies along a correlation between low-frequency QPOs and black hole mass from stellar and intermediate mass black holes to AGNs, similar to the known correlation in high-frequency QPOs.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2018
- DOI:
- 10.3847/2041-8213/aac88c
- arXiv:
- arXiv:1805.12154
- Bibcode:
- 2018ApJ...860L..10S
- Keywords:
-
- accretion;
- accretion disks;
- galaxies: active;
- galaxies: Seyfert;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 6 pages, 4 figures, Accepted for Publication in ApJ Letters