Parker, M. L.3; Wilkins, D. R.4; Fabian, A. C.3; Grupe, D.15; Dauser, T.6; Matt, G.7; Harrison, F. A.16; Brenneman, L.9; Boggs, S. E.10; Christensen, Finn Erland1; Craig, W. W.17; Gallo, L. C.4; Hailey, C. J.17; Kara, E.3; Komossa, S.12; Marinucci, A.7; Miller, J. M.13; Risaliti, G.9; Stern, D.16; Walton, D. J.16; Zhang, W. W.18
1 National Space Institute, Technical University of Denmark2 Astrophysics, National Space Institute, Technical University of Denmark3 University of Cambridge4 Saint Mary's University5 Pennsylvania State University6 Dr. Karl Remeis-Observatory and Erlangen Centre for Astroparticle Physics7 Università degli Studi Roma Tre8 California Institute of Technology9 Harvard-Smithsonian Center for Astrophysics10 University of California11 Columbia University12 Max-Planck-Institut13 University of Michigan14 NASA Goddard Space Flight Center15 Pennsylvania State University16 California Institute of Technology17 Columbia University18 NASA Goddard Space Flight Center
We present 3-50 keV NuSTAR observations of the active galactic nuclei Mrk 335 in a very low flux state. The spectrum is dominated by very strong features at the energies of the iron line at 5-7 keV and Compton hump from 10-30 keV. The source is variable during the observation, with the variability concentrated at low energies, which suggesting either a relativistic reflection or a variable absorption scenario. In this work, we focus on the reflection interpretation, making use of new relativistic reflection models that self consistently calculate the reflection fraction, relativistic blurring and angle-dependent reflection spectrum for different coronal heights to model the spectra. We find that the spectra can be well fitted with relativistic reflection, and that the lowest flux state spectrum is described by reflection alone, suggesting the effects of extreme light-bending occurring within similar to 2 gravitational radii (R-G) of the event horizon. The reflection fraction decreases sharply with increasing flux, consistent with a point source moving up to above 10 R-G as the source brightens. We constrain the spin parameter to greater than 0.9 at the 3 sigma confidence level. By adding a spin-dependent upper limit on the reflection fraction to our models, we demonstrate that this can be a powerful way of constraining the spin parameter, particularly in reflection dominated states. We also calculate a detailed emissivity profile for the iron line, and find that it closely matches theoretical predictions for a compact source within a few R-G of the black hole.
Monthly Notices of the Royal Astronomical Society, 2014, Vol 443, Issue 2, p. 1723-1732
ASTRONOMY; ACTIVE GALACTIC NUCLEI; X-RAY REFLECTION; ACCRETING BLACK-HOLES; XMM-NEWTON; FLUX STATE; LONG HARD; NGC 4051; IRAS 13224-3809; EMISSION-LINES; 1H 0707-495; galaxies: active; galaxies: individual: Mrk 335; galaxies: Seyfert