Asymmetric structure in Sgr A* at 3 mm from closure phase measurements with VLBA, GBT and LMT

Christiaan D. Brinkerink, Cornelia Müller, Heino Falcke, Geoffrey C. Bower, Thomas P. Krichbaum, Edgar Castillo, Adam T. Deller, Sheperd S. Doeleman, Raquel Fraga-Encinas, Ciriaco Goddi, Antonio Hernández-Gómez, David H. Hughes, Michael Kramer, Jonathan Léon-Tavares, Laurent Loinard, Alfredo Montaña, Monika Mościbrodzka, Gisela N. Ortiz-León, David Sanchez-Arguelles, Remo P.J. TilanusGrant W. Wilson, J. Anton Zensus

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)1382-1392
Number of pages11
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
StatePublished - Oct 21 2016
Externally publishedYes


  • Accretion, accretion discs
  • Galaxies: active
  • Galaxies: jets
  • Radio continuum: galaxies
  • Techniques: interferometric

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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