223 citations · 1.3k across the 23 of their papers we have counts for
23 papers
Parsec-scale polarimetry and kinematics of a spine-sheath jet in the neutrino-blazar TXS 0506+056
F. Eppel, P. Benke, C. Degli Agosti +10
In 2017, the blazar TXS 0506+056 showed a remarkable gamma-ray outburst simultaneously with a high-energy neutrino detection by IceCube from the same sky region. The significance o…
A hidden ultra-relativistic spine in the jet of a neutrino-associated blazar
Y. Y. Kovalev, F. Eppel, D. C. Homan +16
Supermassive black holes launch powerful jets of plasma that can accelerate particles to extreme energies, but the physical conditions required to produce high-energy neutrinos rem…
Compelling Evidence for a Harmonic in the Light Curve of the Supermassive Black Hole Binary Candidate PKS J1309+1154
A. C. S. Readhead, M. F. Aller, A. G. Sullivan +23
We recently discovered a supermassive black hole binary (SMBHB) candidate, PKS J1309+1154, in the combined 46-yr University of Michigan Radio Astronomy Observatory (UMRAO) plus Owe…
Multi-messenger flare in the quasar PKS 0446+11
Y. Y. Kovalev, M. F. Aller, A. K. Erkenov +15
The physical mechanisms driving neutrino and electromagnetic flares in blazars remain poorly understood. We investigate a prominent multi-messenger flare in the quasar PKS 1424+240…
A Search for Supermassive Black Hole Binary Candidates in 46-Year Radio Light Curves of 83 Blazars
B. Molina, P. Mróz, P. V. De la Parra +23
The combined University of Michigan Radio Astronomy Observatory (UMRAO) and Owens Valley Radio Observatory (OVRO) blazar monitoring programs at 14.5/15 GHz provide uninterrupted li…
Looking into the Jet Cone of the Neutrino-Associated Very High Energy Blazar PKS 1424+240
Y. Y. Kovalev, A. B. Pushkarev, J. L. Gomez +7
The acceleration process of massive particles as well as the production of very high energy (VHE) photons and neutrinos remains a fundamental challenge in astrophysics. We investig…
Exploring Compact Symmetric Objects with Complex Morphologies
E. E. Sheldahl, G. B. Taylor, S. E. Tremblay +9
Compact symmetric objects (CSOs) are a unique class of jetted active galactic nuclei (AGN) defined by sub-kpc radio emission, showing radio structure on both sides of the central e…
The Radio Spectra of High Luminosity Compact Symmetric Objects (CSO-2s): Implications for Studies of Compact Jetted Active Galactic Nuclei
P. V. de la Parra, A. C. S Readhead, T. Herbig +18
This paper addresses, for the first time, a key aspect of the phenomenology of Compact Symmetric Objects (CSOs) -- the characteristics of their radio spectra. We present a radio-sp…
PKS 2131-021 -- Discovery of Strong Coherent Sinusoidal Variations from Radio to Optical Frequencies: Compelling Evidence for a Blazar Supermassive Black Hole Binary
S. Kiehlmann, P. V. de la Parra, A. G. Sullivan +31
Haystack and Owens Valley Radio Observatory (OVRO) observations recently revealed strong, intermittent, sinusoidal total flux-density variations that maintained coherence between 1…
Compact Symmetric Objects -- II Confirmation of a Distinct Population of High-Luminosity Jetted Active Galaxies
S. Kiehlmann, A. C. S. Readhead, S. O'Neill +10
Compact Symmetric Objects (CSOs) are compact (<1 kpc), jetted Active Galactic Nuclei (AGN), whose jet axes are not aligned close to the line of sight, and whose observed emission i…
Reversals in the Direction of Polarization Rotation in OJ 287
M. H. Cohen, H. D. Aller, M. F. Aller +7
We have obtained a smooth time series for the Electric Vector Position Angle (EVPA) of the blazar OJ 287 at centimeter wavelengths, by making adjustments to archival value…
Why Haven't Many of the Brightest Radio Loud Blazars Been Detected by Fermi ?
M. L. Lister, M. F. Aller. H. D. Aller. T. Hovatta, W. Max-Morbeck +3
We use the complete MOJAVE 1.5 Jy sample of active galactic nuclei (AGN) to examine the gamma-ray detection statistics of the brightest radio-loud blazars in the northern sky. We f…
MOJAVE XII: Acceleration and Collimation of Blazar Jets on Parsec Scales
D. C. Homan, M. L. Lister, Y. Y. Kovalev +5
We report on the acceleration properties of 329 features in 95 blazar jets from the MOJAVE VLBA program. Nearly half the features and three-quarters of the jets show significant ch…
Studies of the Jet in BL Lacertae I. Recollimation Shock and Moving Emission Features
M. H. Cohen, D. L. Meier, T. G. Arshakian +7
Parsec-scale VLBA images of BL Lac at 15 GHz show that the jet contains a permanent quasi-stationary emission feature 0.26 mas (0.34 pc projected) from the core, along with numerou…
Discovery of a new TeV gamma-ray source: VER J0521+211
VERITAS Collaboration, S. Archambault, T. Arlen +83
We report the detection of a new TeV gamma-ray source, VER J0521+211, based on observations made with the VERITAS imaging atmospheric Cherenkov telescope array. These observations…
VLBA observations of a rare multiple quasar imaging event caused by refraction in the interstellar medium
A. B. Pushkarev, Y. Y. Kovalev, M. L. Lister +9
We report on the first detection of the theoretically-predicted rare phenomenon of multiple parsec-scale imaging of an active galactic nucleus induced by refractive effects due to…
Rapid TeV Gamma-Ray Flaring of BL Lacertae
T. Arlen, T. Aune, M. Beilicke +83
We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flar…
Chandra & HST Imaging of the Quasars PKS B0106+013 & 3C345: Inverse Compton X-rays and Magnetized Jets
Preeti Kharb, Matthew Lister, Herman Marshall +1
We present results from deep (70 ks) Chandra ACIS observations and Hubble Space Telescope ACS F475W observations of two highly optically polarized quasars belonging to the MOJAVE b…
Gamma-Ray and Parsec-Scale Jet Properties of a Complete Sample of Blazars From the MOJAVE Program
M. L. Lister, M. Aller, H. Aller +142
We investigate the Fermi LAT gamma-ray and 15 GHz VLBA radio properties of a joint gamma-ray- and radio-selected sample of AGNs obtained during the first 11 months of the Fermi mis…
Radio/gamma-ray time delay in the parsec-scale cores of active galactic nuclei
A. B. Pushkarev, Y. Y. Kovalev, M. L. Lister
We report the detection of a non-zero time delay between radio emission measured by the VLBA at 15.4 GHz and gamma-ray radiation (gamma-ray leads radio) registered by the Large Are…
PKS 1502+106: a new and distant gamma-ray blazar in outburst discovered by the Fermi Large Area Telescope
The Fermi LAT Collaboration, the Multifrequency Campaing Collaboration
The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope discovered a rapid (about 5 days duration), high-energy (E >100 MeV) gamma-ray outburst from a source id…
Relativistic beaming and gamma-ray brightness of blazars
T. Savolainen, D. C. Homan, T. Hovatta +5
We investigate the dependence of gamma-ray brightness of blazars on intrinsic properties of their parsec-scale radio jets and the implication for relativistic beaming. By combining…
Fermi Discovery of Gamma-Ray Emission from NGC 1275
LAT Collaboration, A. A. Abdo, H. D. Aller +6
We report the discovery of high-energy (E>100 MeV) gamma-ray emission from NGC 1275, a giant elliptical galaxy lying at the center of the Perseus cluster of galaxies, based on obse…