Brinkerink, Christiaan D., Müller, Cornelia, Falcke, Heino, Bower, Geoffrey C., Krichbaum, Thomas P., Castillo, Edgar, Deller, Adam T., Doeleman, Sheperd S., Fraga-Encinas, Raquel, Goddi, Ciriaco, Hernández-Gómez, Antonio, Hughes, David H., Kramer, Michael, Léon-Tavares, Jonathan, Loinard, Laurent, Montaña, Alfredo, Moscibrodzka, Monika, Ortiz-León, Gisela N., Sanchez-Arguelles, David, Tilanus, Remo P. J., Wilson, Grant W., and Zensus, J. Anton. 2016. "Asymmetric structure in Sgr A* at 3 mm from closure phase measurements with VLBA, GBT and LMT." Monthly Notices of the Royal Astronomical Society, 462 1382–1392. https://doi.org/10.1093/mnras/stw1743.
We present the results of a closure phase analysis of 3 mm very long baseline interferometry measurements performed on Sagittarius A* (Sgr A*). We have analysed observations made in 2015 May using the Very Long Baseline Array, the Robert C. Byrd Green Bank Telescope and the Large Millimeter Telescope Alfonso Serrano and obtained non-zero closure phase measurements on several station triangles - indicative of a non-point-symmetric source structure. The data are fitted with an asymmetric source structure model in Sgr A*, represented by a simple two-component model, which favours a fainter component due east of the main source. This result is discussed in light of a scattering screen with substructure or an intrinsically asymmetric source.
