Astron. Astrophys. Suppl. Ser. 131, 451-467

50 $\mu$as resolution VLBI images of AGN's at $\lambda$3mm

F.T. Rantakyrö ^1,2 - L.B. Båå th³ - D.C. Backer⁴ - R.S. Booth⁵ - J.E. Carlstrom⁶ - D.T. Emerson⁷ - M. Grewing⁸ - H. Hirabayashi⁹ - M.W. Hodges⁶ - M. Inoue⁹ - H. Kobayashi⁹ - T.P. Krichbaum¹⁰ - A.J. Kus¹¹ - J.M. Moran¹² - M. Morimoto⁹ - S. Padin⁶ - R.L. Plambeck⁴ - R. Predmore¹³ - A.E.E. Rogers¹⁴ - C. Schalinski⁸ - A. Witzel¹⁰ - D. Woody⁶ - M.C.H. Wright⁴ - A. Zensus¹⁵

Send offprint request: F.T. Rantakyrö

1 - Istituto di RadioAstronomia-CNR, Via Gobetti 101, I-40129, Bologna, Italy
2 - Joint Institute for VLBI in Europe, Postbus 2, 7990AA Dwingeloo, The Netherlands
3 - Center for Imaging Technologies, Halmstad University, S-301 18 Halmstad, Sweden
4 - University of California, Berkeley CA 94720, U.S.A.
5 - Onsala Space Observatory, S-439 92 Onsala, Sweden
6 - Owens Valley Observatory, California Institute of Technology, Pasadena CA 91125, U.S.A.
7 - NRAO, 949 N. Cherry Ave., Campus Bldg. 65, Tucson AZ 85721-0655, U.S.A.
8 - IRAM, 300 rue de la Piscine, F-38406 St. Martin d'Hères, France
9 - Nobeyama Radio Observatory, Nobeyama, Minamisaku, Nagano 384-13, Japan
10 - Max-Planck-Institut für Radioastronomie, Auf dem Huegel 69, D-53121 Bonn, Germany
11 - Torun Radio Observatory, Nicolau Copernicus Observatory, Torun, Poland
12 - Center for Astrophysics, 60 Garden Street, Cambridge MA 02138, U.S.A.
13 - FCRAO, Dept. of Physics and Astronomy, 619 Lederle Graduate Research Center, Univ. of Mass., Box 34517, Amherst, MA, U.S.A.
14 - Northeast Radio Observatory Corp., Haystack Observatory, Westford MA 01886, U.S.A.
15 - NRAO, Socorro NM 87801, U.S.A.

Received July 3, 1997; accepted March 19, 1998

Abstract:

We present 15 images from the global mm-VLBI sessions in 1990 April at 100GHz and 1993 April at 86GHz. These observations probe the central engines of the 16 observed AGN's with up to 50 $\mu$as resolution. Among other sources previously observed with $\lambda$3mm VLBI we present the first $\lambda$3mm maps of 0735+178, 0748+126, 1055+018, 2145+067, and CTA102, in total we have been able to image 13 out of the 16 observed sources. 6 out of the 13 imaged sources observed exhibit curvature and rapid structural changes, although the low dynamic range in two thirds of the maps limits the detection of weak features. Most of the sources have unresolved cores even at this high resolution. There is substantial evidence that the observed sources can be grouped into two general groups: A misaligned population with parsec scale jets in the form of low pitch helices and an aligned population with straight jets with small changes in PA due to intrinsic bends.

Key words: galaxies: jets -- radio continuum: galaxies -- galaxies: active -- galaxies: nuclei