Multiwavelength campaign on Mrk 509
XI. Reverberation of the Fe Kα line
1 School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ, UK
2 INAF – IASF Bologna, via Gobetti 101, 40129 Bologna, Italy
3 SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
4 Dipartimento di Fisica, Università degli Studi Roma Tre, via della Vasca Navale 84, 00146 Roma, Italy
5 Sterrenkundig Instituut, Universiteit Utrecht, PO Box 80000, 3508 TA Utrecht, The Netherlands
6 Centro de Astrobiología (CSIC-INTA), Dep. de Astrofísica, LAEFF, PO Box 78, 28691 Villanueva de la Cañada, Madrid, Spain
7 UJF-Grenoble 1 / CNRS-INSU, Institut de Planétologie et d’Astrophysique de Grenoble (IPAG) UMR 5274, 38041 Grenoble, France
8 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
9 Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
10 Instituto de Astronomía, Universidad Católica del Norte, Avenida Angamos 0610, Casilla 1280, Antofagasta, Chile
11 Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK
12 Department of Physics, Virginia Tech, Blacksburg, VA 24061, USA
13 Department of Physics, Technion-Israel Institute of Technology, 32000 Haifa, Israel
14 Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, RH5 6NT, UK
15 Centrum Astronomiczne im. M. Kopernika, Rabiańska 8, 87-100 Toruń, Poland
16 ISDC Data Centre for Astrophysics, Astronomical Observatory of the University of Geneva, 16 ch. d’Ecogia, 1290 Versoix, Switzerland
17 Department of Astronomy and CRESST, University of Maryland, College Park, MD 20742, USA
18 X-ray Astrophysics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD, 20771, USA
Received: 20 April 2012
Accepted: 25 June 2012
Context. We report on a detailed study of the Fe K emission/absorption complex in the nearby, bright Seyfert 1 galaxy Mrk 509. The study is part of an extensive XMM-Newton monitoring consisting of 10 pointings (~60 ks each) about once every 4 days, and includes a reanalysis of previous XMM-Newton and Chandra observations.
Aims. We aim at understanding the origin and location of the Fe K emission and absorption regions.
Methods. We combine the results of time-resolved spectral analysis on both short and long time-scales including model-independent rms spectra.
Results. Mrk 509 shows a clear (EW = 58 ± 4 eV) neutral Fe Kα emission line that can be decomposed into a narrow (σ = 0.027 keV) component (found in the Chandra HETG data) plus a resolved (σ = 0.22 keV) component. We find the first successful measurement of a linear correlation between the intensity of the resolved line component and the 3–10 keV flux variations on time scales of years down to a few days. The Fe Kα reverberates the hard X-ray continuum without any measurable lag, suggesting that the region producing the resolved Fe Kα component is located within a few light days to a week (r ≲ 103rg) from the black hole (BH). The lack of a redshifted wing in the line poses a lower limit of ≥40 rg for its distance from the BH. The Fe Kα could thus be emitted from the inner regions of the BLR, i.e. within the ~80 light days indicated by the Hβ line measurements. In addition to these two neutral Fe Kα components, we confirm the detection of weak (EW ~ 8–20 eV) ionised Fe K emission. This ionised line can be modelled with either a blend of two narrow Fe xxv and Fe xxvi emission lines (possibly produced by scattering from distant material) or with a single relativistic line produced, in an ionised disc, down to a few rg from the BH. In the latter interpretation, the presence of an ionised standard α-disc, down to a few rg, is consistent with the source high Eddington ratio. Finally, we observe a weakening/disappearing of the medium- and high-velocity high-ionisation Fe K wind features found in previous XMM-Newton observations.
Conclusions. This campaign has made the first reverberation measurement of the resolved component of the Fe Kα line possible, from which we can infer a location for the bulk of its emission at a distance of r ~ 40–1000 rg from the BH.
Key words: accretion, accretion disks / black hole physics / methods: data analysis / galaxies: individual: Mrk 509 / galaxies: active / galaxies: Seyfert
© ESO, 2012