First 230? GHz VLBI fringes on 3C 279 using the APEX Telescope (Research Note)
Journal article, 2015
Aims. We report about a 230? GHz very long baseline interferometry (VLBI) fringe finder observation of blazar 3C 279 with the APEX telescope in Chile, the phased submillimeter array (SMA), and the SMT of the Arizona Radio Observatory (ARO). Methods. We installed VLBI equipment and measured the APEX station position to 1? cm accuracy (1σ). We then observed 3C 279 on 2012 May 7 in a 5? h 230? GHz VLBI track with baseline lengths of 2800? Mλ to 7200? Mλ and a finest fringe spacing of 28.6? μas. Results. Fringes were detected on all baselines with signal-to-noise ratios of 12 to 55 in 420? s. The correlated flux density on the longest baseline was ∼0.3? Jy beam-1, out of a total flux density of 19.8? Jy. Visibility data suggest an emission region ≤ 38? μas in size, and at least two components, possibly polarized. We find a lower limit of the brightness temperature of the inner jet region of about 1010? K. Lastly, we find an upper limit of 20% on the linear polarization fraction at a fringe spacing of ∼ 38? μas. Conclusions. With APEX the angular resolution of 230? GHz VLBI improves to 28.6? μas. This allows one to resolve the last-photon ring around the Galactic Center black hole event horizon, expected to be 40? μas in diameter, and probe radio jet launching at unprecedented resolution, down to a few gravitational radii in galaxies like M 87. To probe the structure in the inner parsecs of 3C 279 in detail, follow-up observations with APEX and five other mm-VLBI stations have been conducted (March 2013) and are being analyzed.
Telescopes
Galaxies: individual: 3C 279
Galaxies: jets
Instrumentation: high angular resolution
Author
Jan Wagner
Korea Astronomy and Space Science Institute
Max Planck Society
A. Roy
Max Planck Society
T.P. Krichbaum
Max Planck Society
W. Alef
Max Planck Society
A. Bansod
Max Planck Society
A. Bertarini
Max Planck Society
University of Bonn
R. Güsten
Max Planck Society
D. Graham
Max Planck Society
J. Hodgson
Max Planck Society
R. Märtens
Max Planck Society
K. Menten
Max Planck Society
D. Muders
Max Planck Society
H. Rottmann
Max Planck Society
G. Tuccari
Max Planck Society
Istituto nazionale di astrofisica (INAF)
A. Weiss
Max Planck Society
G. Wieching
Max Planck Society
M. Wunderlich
Max Planck Society
A.J. Zensus
Max Planck Society
J.P. Araneda
European Southern Observatory Santiago
O. Arriagada
European Southern Observatory Santiago
M. Cantzler
European Southern Observatory Santiago
C. Duran
European Southern Observatory Santiago
F.M. Montenegro-Montes
European Southern Observatory Santiago
R. Olivares
European Southern Observatory Santiago
P. Caro
Per Bergman
Chalmers, Earth and Space Sciences, Onsala Space Observatory
John Conway
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Rüdiger Haas
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Jan Johansson
Chalmers, Earth and Space Sciences, Space Geodesy and Geodynamics
Michael Lindqvist
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Hans Olofsson
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Miroslav Pantaleev
Chalmers, Earth and Space Sciences, Onsala Space Observatory
S. Buttaccio
Istituto nazionale di astrofisica (INAF)
R. Cappallo
Massachusetts Institute of Technology (MIT)
G. Crew
Massachusetts Institute of Technology (MIT)
S. Doeleman
Massachusetts Institute of Technology (MIT)
V. Fish
Massachusetts Institute of Technology (MIT)
R.S. Lu
Massachusetts Institute of Technology (MIT)
C. Ruszczyk
Massachusetts Institute of Technology (MIT)
J. SooHoo
Massachusetts Institute of Technology (MIT)
M. Titus
Massachusetts Institute of Technology (MIT)
R. Freund
University of Arizona
D. P. Marrone
University of Arizona
P. Strittmatter
University of Arizona
L. Ziurys
University of Arizona
R. Blundell
Harvard-Smithsonian Center for Astrophysics
R. Primiani
Harvard-Smithsonian Center for Astrophysics
J. Weintroub
Harvard-Smithsonian Center for Astrophysics
K. Young
Harvard-Smithsonian Center for Astrophysics
M. Bremer
Institut de Radioastronomie Millimétrique (IRAM)
S. Sánchez
Institut de Radioastronomie Millimétrique (IRAM)
A.P. Marscher
Boston University
R. Chilson
Academia Sinica
K. Asada
Academia Sinica
M. Inoue
Academia Sinica
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 581 A32Subject Categories
Fusion, Plasma and Space Physics
DOI
10.1051/0004-6361/201423613