2.7k citations · 6.9k across the 59 of their papers we have counts for
25 papers · 1 filter
A Multi-Epoch VLBI Survey of the Kinematics of CJF Sources; Part I: Model-Fit Parameters and Maps
S. Britzen, R. C. Vermeulen, G. B. Taylor +7
Context: This is the first of a series of papers presenting VLBI observations of the 293 Caltech-Jodrell Bank Flat-Spectrum (hereafter CJF) sources and their analysis. Aims: One of…
A Multi-epoch VLBI Survey of the Kinematics of Caltech-Jodrell Bank Flat-Spectrum Sources, Part II: Analysis of the Kinematics
S. Britzen, R. C. Vermeulen, R. M. Campbell +7
Context: This is the second of a series of papers presenting VLBI observations of the 293 Caltech-Jodrell Bank Flat-Spectrum (hereafter CJF) sources and their analysis. Aims: To ob…
Environment of compact extragalactic radio sources
A. Labiano, C. P. O'Dea, P. D. Barthel +1
We have studied the interrelation of young AGN with their hosts. The objects of study are the young and powerful GPS and CSS radio sources. Due to their small size, GPS and CSS sou…
Probing the polarization characteristics of SS433 on mas scales
Z. Paragi, R. C. Vermeulen, D. C. Homan +5
We present a status report of dedicated circular polarization (CP) global VLBI observations of SS433. The total intensity image of the source is presented. We do not detect linear…
The unfriendly ISM in the radio galaxy 4C12.50 (PKS 1345+12)
R. Morganti, T. A. Oosterloo, C. N. Tadhunter +4
The radio source 4C12.50 has often been suggested to be a prime candidate for the link between ultraluminous infrared galaxies and young radio galaxies. A VLBI study of the neutral…
Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei III. Kinematics of Parsec-Scale Radio Jets
K. I. Kellermann, M. L. Lister, D. C. Homan +6
We report the results of a 15 GHz (2 cm) multi-epoch VLBA program, begun in 1994 to study the outflow in radio jets ejected from quasars and active galaxies. The observed flow of 2…
Relativistic Phenomena in Active Galactic Nuclei
M. H. Cohen, M. L. Lister, R. C. Vermeulen
The idea that the radio jets in AGN contain material in relativistic motion is supported by many lines of observational evidence, including morphology, brightness temperature estim…
Variability and Velocity of Superluminal Sources
M. H. Cohen, M. A. Russo, D. C. Homan +5
We investigate the relation between the Doppler factor determined from variations in total flux at 22 and 37 GHz, and the apparent transverse velocity determined from VLBA observat…
Ionised, Atomic, and Molecular Gas around the Twin Radio Jets of NGC1052
R. C. Vermeulen, E. Ros, J. A. Zensus +3
The bright radio structure of the LINER elliptical galaxy NGC1052 is dominated by bi-symmetric jets on parsec scales. Features move outward on both sides of the core at v_{app}~0.2…
Motion Statistics in the CJ Survey -- The Status in October 2002
R. C. Vermeulen, S. Britzen, G. B. Taylor +4
In the Caltech-Jodrell Survey of bright flat-spectrum radio sources, 3-5 epochs have now been observed for nearly all 293 sources; a uniquely large sample. The derivation of compon…
HI Absorption in GPS/CSS Sources
Y. M. Pihlstroem, J. E. Conway, R. C. Vermeulen
Combining our own observations with data from the literature, we consider the incidence of HI absorption in Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources…
Superluminal Motion and Relativistic Beaming in Blazar Jets
K. I. Kellermann, M. L. Lister, D. C. Homan +5
High resolution radio observations remain the most direct way to study the formation and evolution of radio jets associated with the accretion onto massive black holes. We report p…
4C +12.50: A Superluminal Precessing Jet in the Recent Merger System IRAS 13451+1232
M. L. Lister, K. I. Kellermann, R. C. Vermeulen +3
We present the results of a multi-epoch VLBA study of the powerful radio source 4C +12.50 (PKS 1345+125) at a wavelength of 2 cm. This compact radio source is associated with a hid…
The shroud around the "compact, symmetric" radio jets in NGC 1052
R. C. Vermeulen, E. Ros, K. I. Kellermann +3
This is a paper on young jet material in a frustratingly complex environment. NGC 1052 has a compact, flat- or GHz-peaked-spectrum radio nucleus consisting of bi-symmetric jets, or…
The Equatorial Outflow of SS433
Z. Paragi, I. Fejes, R. C. Vermeulen +3
We present VLBI imaging results for SS433 from the period 1995-2000. An equatorial emission region is detected and confirmed in 7 experiments at 1.6 and 5 GHz. The structure of the…
Kinematics of parsec-scale structures in AGN: the 2cm VLBA Survey
E. Ros, K. I. Kellermann, M. L. Lister +5
We are investigating the kinematics of jets in active galactic nuclei on parsec scales by studying a representative population of sources. This study is being carried out using the…
Deep Westerbork 1.4 GHz Imaging of the Bootes Field
W. H. de Vries, R. Morganti, H. J. A. Rottgering +4
We present the results from our deep (16x12 hour) Westerbork Synthesis Radio Telescope (WSRT) observations of the approximately 7 square degree Bootes Deep Field, centered at 14h32…
Cold Gas Kinematics in an L* Spiral Galaxy at z=0.437: The Nature of Damped Lyman-alpha Absorbers
F. H. Briggs, A. G. de Bruyn, R. C. Vermeulen
Westerbork Radio Synthesis Telescope observations of the redshifted 21cm line absorber against the z_em = 0.871 double lobed quasar 3C196 show that the intervening absorber is an L…
Redshifts and Neutral Hydrogen Observations of Compact Symmetric Objects in the COINS Sample
A. B. Peck, G. B. Taylor, C. D. Fassnacht +2
Compact Symmetric Objects (CSOs) are young radio galaxies whose jet axes lie close to the plane of the sky, and whose appearance is therefore not dominated by relativistic beaming…
VLBA Absorption Imaging of Ionized Gas Associated with the Accretion Disk in NGC 1275
R. C. Walker, V. Dhawan, J. D. Romney +2
Nearly simultaneous VLBA observations of 3C 84, the radio source associated with NGC 1275, have been made at multiple frequencies to study the free-free absorption of the northern,…
The inner radio jet region and the complex environment of SS433
Z. Paragi, R. C. Vermeulen, I. Fejes +3
We present multi-frequency VLBA+VLA observations of SS433 at 1.6, 5 and 15 GHz. These observations provide the highest angular resolution radio spectral index maps ever made for th…
The Proper Motion of SgrA*: I. First VLBA Results
M. J. Reid, A. C. S. Readhead, R. C. Vermeulen +1
We observed Sgr A* and two extragalactic radio sources nearby in angle with the VLBA over a period of two years and measured relative positions with an accuracy approaching 0.1 mas…
Sub-milliarcsecond Imaging of Quasars and AGN
K. I. Kellermann, R. C. Vermeulen, J. A. Zensus +1
We have used the VLBA at 15 GHz to image the structure of 132 strong compact AGN and quasars with a resolution better than one milliarcsecond and a dynamic range typically exceedin…
Bi-Directional Relativistic Jets of the Radio Galaxy 1946+708: Constraints on the Hubble Constant
G. B. Taylor, R. C. Vermeulen
We present measurements of bi-directional motions in the jets of the radio galaxy 1946+708 at z=0.101. This is a Compact Symmetric Object with striking S-symmetry. Sensitive 15 GHz…