@article{13512,
  author = {GRAVITY Collaboration: and A. Amorim and G. Bourdarot and W. Brandner and Y. Cao and Y. Clenet and R. Davies and P. de Zeeuw and Jason Dexter and A. Drescher and A. Eckart and F. Eisenhauer and M. Fabricius and H. Feuchtgruber and N. Schreiber 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 K. Perraut and G. Perrin and B. Peterson and P. Petrucci and O. Pfuhl and A. Prieto and S. Rabien and D. Rouan and D. Santos and J. Shangguan and T. Shimizu and A. Sternberg and C. Straubmeier and E. Sturm and L. Tacconi and K. Tristram and F. Widmann and J. Woillez},
  title = {VLTI/GRAVITY interferometric measurements of the innermost dust structure sizes around active galactic nuclei⋆},
  abstract = {<p>We present new Very Large Telescope Interferometer (VLTI)/GRAVITY near-infrared interferometric measurements of the angular size of the innermost hot dust continuum for 14 type 1 active galactic nuclei (AGNs). The angular sizes are resolved on scales of ∼0.7 mas and the inferred ring radii range from 0.028 to 1.33 pc, comparable to those reported previously and a factor of 10−20 smaller than the mid-infrared sizes in the literature. Combining our new data with previously published values, we compiled a sample of 25 AGNs with bolometric luminosity ranging from 1042 to 1047 erg s−1, with which we studied the radius-luminosity (R − L) relation for the hot dust structure. Our interferometric measurements of radius are offset by a factor of 2 from the equivalent relation derived through reverberation mapping. Using a simple model to explore the dust structure’s geometry, we conclude that this offset can be explained if the 2 μm emitting surface has a concave shape. Our data show that the slope of the relation is in line with the canonical R ∝ L0.5 when using an appropriately non-linear correction for bolometric luminosity. In contrast, using optical luminosity or applying a constant bolometric correction to it results in a significant deviation in the slope, suggesting a potential luminosity dependence on the spectral energy distribution. Over four orders of magnitude in luminosity, the intrinsic scatter around the R − L relation is 0.2 dex, suggesting a tight correlation between the innermost hot dust structure size and the AGN luminosity.</p>},
  year = {2024},
  journal = {Astronomy & Astrophysics},
  volume = {690},
  pages = {A76},
  month = {2024-10},
  url = {"https://doi.org/10.1051/0004-6361/202450746"},
  doi = {"10.1051/0004-6361/202450746"},
}