105 citations · 645 across the 18 of their papers we have counts for
9 papers · 1 filter
The Fastest Relativistic Jets: VLBA Observations of Blazars with Apparent Speeds Exceeding 25c
B. G. Piner, D. Bhattarai, P. G. Edwards +1
We have measured peak apparent speeds of 25.6 +/- 7.0c, 25.6 +/- 4.4c, and 28.2 +/- 6.6c in the jets of 0235+164, 0827+243, and 1406-076, respectively, based on six epochs of high-…
What Happened to the NGC 6251 Counterjet?
Dayton L. Jones, Ann E. Wehrle
We have used the VLBA to produce a high dynamic range image of the nucleus of NGC 6251 at 1.6 GHz and snapshot images at 5.0, 8.4, and 15.3 GHz to search for emission from a parsec…
Orientation and Speed of the Parsec-Scale Jet in NGC4261 (3C270)
B. Glenn Piner, Dayton L. Jones, Ann E. Wehrle
NGC4261 (3C270) is an elliptical galaxy containing a 300-parsec scale nuclear disk of gas and dust imaged by the Hubble Space Telescope (HST), around a central supermassive black h…
In the Shadow of the Accretion Disk: Higher Resolution Imaging of the Central Parsec in NGC 4261
Dayton L. Jones, Ann E. Wehrle, B. Glenn Piner +1
The physical conditions in the inner parsec of accretion disks believed to orbit the central black holes in active galactic nuclei can be probed by imaging the absorption (by ioniz…
Space VLBI at Low Frequencies
D. Jones, R. Allen, J. Basart +25
At sufficiently low frequencies, no ground-based radio array will be able to produce high resolution images while looking through the ionosphere. A space-based array will be needed…
The Radio Jets and Accretion Disk in NGC 4261
D. L. Jones, A. E. Wehrle, D. L. Meier +1
The structure of AGN accretion disks on sub-parsec scales can be probed through free-free absorption of synchrotron emission from the base of symmetric radio jets. We present new V…
VLBA Imaging of NGC 4261: Symmetric Parsec-scale Jets and the Inner Accretion Region
Dayton L. Jones, Ann E. Wehrle
We observed the nuclear region of NGC 4261 (3C270) with the VLBA at two frequencies (1.6 and 8.4 GHz) simultaneously. We find that the position angle of the parsec-scale radio axis…
PKS 1830-211: A Possible Compound Gravitational Lens
J. E. J. Lovell, J. E. Reynolds, D. L. Jauncey +11
Measurements of the properties of gravitational lenses have the power to tell us what sort of universe we live in. The brightest known radio Einstein ring/gravitational lens PKS 18…
Discovery of a Sub-Parsec Radio Counterjet in the Nucleus of Centaurus A
D. L. Jones, S. J. Tingay, D. W. Murphy +22
A sub-parsec scale radio counterjet has been detected in the nucleus of the closest radio galaxy, Centaurus A (NGC 5128), with VLBI imaging at 2.3 and 8.4 GHz. This is one of the f…