First 230? GHz VLBI fringes on 3C 279 using the APEX Telescope (Research Note)
Artikel i vetenskaplig tidskrift, 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.

Instrumentation: high angular resolution

Telescopes

Galaxies: jets

Galaxies: individual: 3C 279

Författare

Jan Wagner

Korea Astronomy and Space Science Institute

Max Planck Institut fur Radioastronomie

A. Roy

Max Planck Institut fur Radioastronomie

T.P. Krichbaum

Max Planck Institut fur Radioastronomie

W. Alef

Max Planck Institut fur Radioastronomie

A. Bansod

Max Planck Institut fur Radioastronomie

A. Bertarini

Max Planck Institut fur Radioastronomie

Universitat Bonn

R. Güsten

Max Planck Institut fur Radioastronomie

D. Graham

Max Planck Institut fur Radioastronomie

J. Hodgson

Max Planck Institut fur Radioastronomie

R. Märtens

Max Planck Institut fur Radioastronomie

K. Menten

Max Planck Institut fur Radioastronomie

D. Muders

Max Planck Institut fur Radioastronomie

H. Rottmann

Max Planck Institut fur Radioastronomie

G. Tuccari

Istituto Nazionale Di Astrofisica, Rome

Max Planck Institut fur Radioastronomie

A. Weiss

Max Planck Institut fur Radioastronomie

G. Wieching

Max Planck Institut fur Radioastronomie

M. Wunderlich

Max Planck Institut fur Radioastronomie

A.J. Zensus

Max Planck Institut fur Radioastronomie

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, Rymd- och geovetenskap, Onsala rymdobservatorium

John Conway

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Rüdiger Haas

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Jan Johansson

Chalmers, Rymd- och geovetenskap, Rymdgeodesi och geodynamik

Michael Lindqvist

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Hans Olofsson

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

Miroslav Pantaleev

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

S. Buttaccio

Istituto Nazionale Di Astrofisica, Rome

R. Cappallo

MIT Haystack Observatory

G. Crew

MIT Haystack Observatory

S. Doeleman

MIT Haystack Observatory

V. Fish

MIT Haystack Observatory

R.S. Lu

MIT Haystack Observatory

C. Ruszczyk

MIT Haystack Observatory

J. SooHoo

MIT Haystack Observatory

M. Titus

MIT Haystack Observatory

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

IRAM Institut de RadioAstronomie Millimetrique

S. Sánchez

Instituto de Radioastronomia Milimetrica

A.P. Marscher

Boston University

R. Chilson

Institute of Astrophysics and Astronomy, Academia Sinica Taiwan

K. Asada

Institute of Astrophysics and Astronomy, Academia Sinica Taiwan

M. Inoue

Institute of Astrophysics and Astronomy, Academia Sinica Taiwan

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 581 A32

Ämneskategorier

Fusion, plasma och rymdfysik

DOI

10.1051/0004-6361/201423613