Discovery of high-frequency iron K lags in Ark 564 and Mrk 335
Abstract
We use archival XMM-Newton observations of Ark 564 and Mrk 335 to calculate the frequency-dependent time lags for these two well-studied sources. We discover high-frequency Fe K lags in both sources, indicating that the red wing of the line precedes the rest-frame energy by roughly 100 and 150 s for Ark 564 and Mrk 335, respectively. Including these two new sources, Fe K reverberation lags have been observed in seven Seyfert galaxies. We examine the low-frequency lag-energy spectrum, which is smooth, and shows no feature of reverberation, as would be expected if the low-frequency lags were produced by distant reflection off circumnuclear material. The clear differences in the low- and high-frequency lag-energy spectra indicate that the lags are produced by two distinct physical processes. Finally, we find that the amplitude of the Fe K lag scales with black hole mass for these seven sources, consistent with a relativistic reflection model where the lag is the light travel delay associated with reflection of continuum photons off the inner disc.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2013
- DOI:
- 10.1093/mnras/stt1055
- arXiv:
- arXiv:1306.2551
- Bibcode:
- 2013MNRAS.434.1129K
- Keywords:
-
- black hole physics;
- galaxies: active;
- X-rays: galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 10 pages, 12 figures, accepted for publication in MNRAS