Quasi-periodicities of the BL Lacertae Object PKS 2155-304
Abstract
We have searched for periodicities in our VRIJHK photometry of PKS 2155-304, which covers the years 2005-2012. A peak of the Fourier spectrum with high significance is found at T ~ 315 days, confirming the recent findings by Zhang et al. The examination of the gamma-ray light curves from the Fermi archives yields a significant signal at ~2T, which, while nominally significant, involves data spanning only ~6T. Assuming a black hole mass of 109 M ⊙, the Keplerian distance corresponding to the quasi-period T is ~1016 cm, about 50 Schwarzschild radii.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 2014
- DOI:
- 10.1088/2041-8205/793/1/L1
- arXiv:
- arXiv:1408.0015
- Bibcode:
- 2014ApJ...793L...1S
- Keywords:
-
- BL Lacertae objects: general;
- BL Lacertae objects: individual: PKS 2155–304;
- galaxies: active;
- methods: statistical;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 11 pages, 1 figure