TY - JOUR
AU - A. Amorim
AU - W. Brandner
AU - Y. Clenet
AU - R. Davies
AU - P. de Zeeuw
AU - Jason Dexter
AU - A. Eckart
AU - F. Eisenhauer
AU - N. Schreiber
AU - F. Gao
AU - P. Garcia
AU - R. Genzel
AU - S. Gillessen
AU - D. Gratadour
AU - S. Hönig
AU - M. Kishimoto
AU - S. Lacour
AU - D. Lutz
AU - F. Millour
AU - H. Netzer
AU - T. Ott
AU - T. Paumard
AU - K. Perraut
AU - G. Perrin
AU - B. Peterson
AU - P. Petrucci
AU - Oliver Pfuhl
AU - M. Prieto
AU - D. Rouan
AU - J. Shangguan
AU - T. Shimizu
AU - M. Schartmann
AU - A. Sternberg
AU - O. Straub
AU - C. Straubmeier
AU - E. Sturm
AU - L. Tacconi
AU - K. Tristram
AU - P. Vermot
AU - S. von Fellenberg
AU - I. Waisberg
AU - F. Widmann
AU - J. Woillez
AB - 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.
BT - Astronomy & Astrophysics
DA - 2020-11
DO - 10.1051/0004-6361/202039067
N2 - 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.
PY - 2020
SE - A154
EP - A154
T2 - Astronomy & Astrophysics
TI - The spatially resolved broad line region of IRAS 09149-6206
UR - https://www.aanda.org/articles/aa/abs/2020/11/aa39067-20/aa39067-20.html
VL - 643
ER -