VLTI/GRAVITY Interferometric Measurements of Innermost Dust Structure Sizes around AGNs

Autor: GRAVITY Collaboration, Amorim, A., Bourdarot, G., Brandner, W., Cao, Y., Clénet, Y., Davies, R., de Zeeuw, P. T., Dexter, J., Drescher, A., Eckart, A., Eisenhauer, F., Fabricius, M., Feuchtgruber, H., Schreiber, N. M. Förster, Garcia, P. J. V., Genzel, R., Gillessen, S., Gratadour, D., Hönig, S., Kishimoto, M., Lacour, S., Lutz, D., Millour, F., Netzer, H., Ott, T., Perraut, K., Perrin, G., Peterson, B. M., Petrucci, P. O., Pfuhl, O., Prieto, M. A., Rabien, S., Rouan, D., Santos, D. J., Shangguan, J., Shimizu, T., Sternberg, A., Straubmeier, C., Sturm, E., Tacconi, L. J., Tristram, K. R. W., Widmann, F., Woillez, J.
Rok vydání: 2024
Předmět:
Zdroj: A&A 690, A76 (2024)
Druh dokumentu: Working Paper
DOI: 10.1051/0004-6361/202450746
Popis: We present new VLTI/GRAVITY near-infrared interferometric measurements of the angular size of the innermost hot dust continuum for 14 type 1 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 10-20 smaller than the mid-infrared sizes in the literature. Combining our new data with previously published values, we compile a sample of 25 AGN with bolometric luminosity ranging from $10^{42}$ to $10^{47} \rm erg~s^{-1}$, with which we study the radius-luminosity (R-L) relation for the hot dust structure. Our interferometric measurements of radius are offset by a factor 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 um emitting surface has a concave shape. Our data show that the slope of the relation is in line with the canonical $R \propto L^{0.5}$ 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 innermost hot dust structure size and the AGN luminosity.
Comment: 14 pages, 5 figures, 4 tables, accepted for publication in A&A
Databáze: arXiv