135 citations · 1.3k across the 68 of their papers we have counts for
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Cosmological Distance Measurements of High Redshift Blazars: OJ 248 (z=0.939) and 4C +38.41 (z=1.814)
Young-Bin Shin, Sang-Sung Lee, Sincheol Kang +3
In this study, we estimated the angular diameter distances to two high-redshift active galactic nuclei (AGNs), OJ 248 (z = 0.939) and 4C +38.41 (z = 1.814), using 43 GHz radio ligh…
SKAVLBI view of AGN jets in the early Universe
C. Spingola, M. Mezcua, Y. Liu +33
Active Galactic Nuclei (AGN) are among the brightest sources in the Universe, and those that are also jetted are uniquely valuable at the earliest epochs, because their relativisti…
A Unified Origin of Faraday Rotation toward 3C 84: The Circumnuclear Ambient Medium within the Parsec-Scale Bondi Radius of the Host Galaxy NGC 1275
Minchul Kam, Jongho Park, Sascha Trippe +11
We present multi-frequency polarimetric observations of 3C 84 obtained with the Korean VLBI Network at 43-141 GHz, the Very Long Baseline Array at 43 GHz, and the High Sensitivity…
The variability angular diameter distance and the intrinsic brightness temperature of active galactic nuclei
Whee Yeon Cheong, Sang-Sung Lee, Chanwoo Song +5
Context. It has recently been suggested that angular diameter distances derived from comparing the variability timescales of blazars to angular size measurements with very long bas…
Exploring connections between the VLBI and optical morphology of AGNs and their host galaxies
David Fernández Gil, Jeffrey A. Hodgson, Benjamin L'Huillier
We analyse VLBI and optical images of AGNs and their host galaxies and look for statistical correlations between the shape and orientation of the galaxy and the direction of the je…
A persistent double nuclear structure in 3C 84
Junghwan Oh, Jeffrey A. Hodgson, Sascha Trippe +11
3C 84 (NGC 1275) is the radio source at the center of the Perseus Cluster and exhibits a bright radio jet. We observed the source with the Global Millimeter VLBI Array (GMVA) betwe…
Pinpointing the jet apex in 3C 84
G. F. Paraschos, J. -Y. Kim, T. P. Krichbaum +4
Jets which are powered by an AGN are a crucial element in the study of their central black holes (BH) and their immediate surroundings. The formation of such jets is the subject of…
East Asian VLBI Network Observations of Active Galactic Nuclei Jets: Imaging with KaVA+Tianma+Nanshan
Yuzhu Cui, Kazuhiro Hada, Motoki Kino +74
The East Asian very-long-baseline interferometry (VLBI) Network (EAVN) is a rapidly evolving international VLBI array that is currently promoted under joint efforts among China, Ja…
Interferometric Monitoring of Gamma-ray Bright AGNs: OJ 287
Jee Won Lee, Sang-Sung Lee, Juan-Carlos Algaba +9
We present the results of simultaneous multi-frequency imaging observations at 22, 43, 86, and 129\,GHz of OJ\,287. We used the Korean VLBI Network as part of the Interferometric M…
Modelling the strongest silicate emission features of local type 1 AGN
M. Martínez-Paredes, O. González-Martín, D. Esparza-Arredondo +8
We measure the 10 and m silicate features in a sample of 67 local () type 1 active galactic nuclei (AGN) with available {\it Spitzer} spectra dominated by non-stellar p…
Origin and Evolution of the Multi-band Variability in the Flat Spectrum Radio Source 4C 38.41
Juan Carlos Algaba, Sang Sung Lee, Bindu Rani +13
The flat spectrum radio quasar 4C 38.41 showed a significant increase of its radio flux density during the period 2012 March - 2015 August which correlates with gamma-ray flaring a…
Jet Kinematics of the Quasar 4C +21.35 from Observations with the KaVA Very Long Baseline Interferometry Array
Taeseok Lee, Sascha Trippe, Motoki Kino +39
We present the jet kinematics of the flat spectrum radio quasar (FSRQ) 4C +21.35 using time-resolved KaVA very long baseline interferometry array radio maps obtained from September…
Spatially resolved origin of mm-wave linear polarization in the nuclear region of 3C 84
J. -Y. Kim, T. P. Krichbaum, A. P. Marscher +12
We report results from a deep polarization imaging of the nearby radio galaxy 3C84 (NGC1275). The source was observed with the Global Millimeter VLBI Array (GMVA) at 86…
Exploring the Nature of the 2016 γ-ray Emission in the Blazar 1749+096
Dae-Won Kim, Sascha Trippe, Sang-Sung Lee +9
Recent Fermi-Large Area Telescope (LAT) light curves indicate an active -ray state spanning about five months from 2016 June to 2016 October in the BL Lac object 1749+096 (OT 08…
A wide and collimated radio jet in 3C 84 on the scale of a few hundred gravitational radii
G. Giovannini, T. Savolainen, M. Orienti +22
Understanding the launching, acceleration, and collimation of jets powered by active galactic nuclei remains an outstanding problem in relativistic astrophysics. This is partly bec…
Long-term millimeter VLBI monitoring of M87 with KVN at milliarcsecond resolution: nuclear spectrum
Jae-Young Kim, Sang-Sung Lee, Jeffrey A. Hodgson +5
We study the centimeter- to millimeter-wavelength synchrotron spectrum of the core of the radio galaxy M87 at spatial scales using four years…
3 mm GMVA Observations of Total and Polarized Emission from Blazar and Radio Galaxy Core Regions
Carolina Casadio, Thomas P. Krichbaum, Alan P. Marscher +7
We present total and linearly polarized 3 mm Global mm-VLBI Array images of a sample of blazars and radio galaxies from the VLBA-BU-BLAZAR 7 mm monitoring program designed to probe…
The Millimeter-Radio Emission of BL Lacertae During Two gamma-ray Outbursts
Dae-Won Kim, Sascha Trippe, Sang-Sung Lee +13
We present a study of the inexplicit connection between radio jet activity and gamma-ray emission of BL Lacertae (BL Lac; 2200+420). We analyze the long-term millimeter activity of…
Interferometric Monitoring of Gamma-ray Bright AGNs: S5 0716+714
Jee Won Lee, Sang-Sung Lee, Jeffrey A. Hodgson +5
We present the results of very long baseline interferometry (VLBI) observations of gamma-ray bright blazar S5 0716+714 using the Korean VLBI Network (KVN) at the 22, 43, 86, and 12…
Interferometric Monitoring of Gamma-ray Bright AGNs I: Results of Single-epoch Multifrequency Observations
Sang-Sung Lee, Kyoaki Wajima, Juan-Carlos Algaba +12
We present results of single-epoch very long baseline interferometry (VLBI) observations of gamma-ray bright active galactic nuclei (AGNs) using the Korean VLBI Network (KVN) at 22…
From galaxy-scale fueling to nuclear-scale feedback: the merger-state of radio galaxies 3C293, 3C305 & 4C12.50
Bjorn Emonts, Raffaella Morganti, Montserrat Villar-Martin +5
Powerful radio galaxies are often associated with gas-rich galaxy mergers. These mergers may provide the fuel to trigger starburst and active galactic nuclear (AGN) activity. In th…
Localizing the rays from blazar PKS 1502+106
Vassilis Karamanavis, L. Fuhrmann, T. P. Krichbaum +7
Blazars are among the most variable objects in the universe. They feature energetic jets of plasma that launch from the cores of these active galactic nuclei (AGN), triggering acti…