Extreme relativistic reflection in the active galaxy ESO 033-G002

Abstract

We present the first high signal-to-noise broad-band X-ray spectrum of the radio-quiet type-2 Seyfert ESO 033-G002, combining data from XMM-Newton and NuSTAR. The nuclear X-ray spectrum is complex, showing evidence for both neutral and ionized absorption, as well as reflection from both the accretion disc and more distant material, but our broad-band coverage allows us to disentangle all of these different components. The total neutral column during this epoch is N<SUB>H</SUB> ~ (5-6) × 10<SUP>22</SUP> $\rm \, cm^{-2}$, consistent with the optical classification of ESO 033-G002 as a type-2 Seyfert but not so large as to prevent us from robustly determining the properties of the innermost accretion flow. The ionized absorption - dominated by lines from Fe XXV and Fe XXVI - reveals a moderately rapid outflow (v<SUB>out</SUB> ~ 5400 $\rm \, km~s^{-1}$) which has a column comparable to the neutral absorption. We find the disc reflection from the innermost regions to be extreme, with a reflection fraction of R<SUB>frac</SUB> ~ 5. This requires strong gravitational lightbending and, in turn, both an extremely compact corona (within ~2 R<SUB>G</SUB> of the black hole) and a rapidly rotating black hole (a* > 0.96). Despite this tight size constraint, with a temperature of kT<SUB>e</SUB> = 40-70 keV the X-ray corona in ESO 033-G002 appears similar to other active galactic nucle in terms of its placement in the compactness-temperature plane, consistent with sitting close to the limit determined by runaway pair production. Finally, combining X-ray spectroscopy, timing, and updated optical spectroscopy, we also estimate the mass of the black hole to be log[M<SUB>BH</SUB>/M<SUB>⊙</SUB>] ~ 7.0-7.5.