@article{12149,
  author = {A. Amorim and W. Brandner and Y. Clenet and R. Davies and P. de Zeeuw and Jason Dexter and A. Eckart and F. Eisenhauer and N. Schreiber and F. Gao and P. Garcia and R. Genzel and S. Gillessen and D. Gratadour and S. Hönig and M. Kishimoto and S. Lacour and D. Lutz and F. Millour and H. Netzer and T. Ott and T. Paumard and K. Perraut and G. Perrin and B. Peterson and P. Petrucci and Oliver Pfuhl and M. Prieto and D. Rouan and J. Shangguan and T. Shimizu and M. Schartmann and A. Sternberg and O. Straub and C. Straubmeier and E. Sturm and L. Tacconi and K. Tristram and P. Vermot and S. von Fellenberg and I. Waisberg and F. Widmann and J. Woillez},
  title = {The spatially resolved broad line region of IRAS 09149-6206},
  abstract = {We present new near-infrared VLTI/GRAVITY interferometric spectra that spatially resolve the broad Brγ emission line in the nucleus of the active galaxy IRAS 09149-6206. We use these data to measure the size of the broad line region (BLR) and estimate the mass of the central black hole. Using an improved phase calibration method that reduces the differential phase uncertainty to 0.05 degree per baseline across the spectrum, we detect a differential phase signal that reaches a maximum of ~0.5 degree between the line and continuum. This represents an offset of ~120 μas (0.14 pc) between the BLR and the centroid of the hot dust distribution traced by the 2.3 μm continuum. The offset is well within the dust sublimation region, which matches the measured ~0.6 mas (0.7 pc) diameter of the continuum. A clear velocity gradient, almost perpendicular to the offset, is traced by the reconstructed photocentres of the spectral channels of the Brγ line. We infer the radius of the BLR to be ~65 μas (0.075 pc), which is consistent with the radius-luminosity relation of nearby active galactic nuclei derived based on the time lag of the Hβ line from reverberation mapping campaigns. Our dynamical modelling indicates the black hole mass is ∼1×108M⊙, which is a little below, but consistent with, the standard MBH-σ∗ relation.},
  year = {2020},
  journal = {Astronomy & Astrophysics},
  volume = {643},
  chapter = {A154},
  pages = {A154},
  month = {2020-11},
  url = {https://www.aanda.org/articles/aa/abs/2020/11/aa39067-20/aa39067-20.html},
  doi = {10.1051/0004-6361/202039067},
}