357 datasets found

We have carried out a Chandra X-ray and multifrequency radio Very Long Baseline Array study of the active galactic nucleus (AGN) TXS0128+554, which is associated with the Fermi...

In this work, we exploit the luminosity of the broad-line region (BLR) for 50 Fermi blazars through matching the coordinates between the Sloan Digital Sky Survey catalog, Fermi...

We present the earliest astronomical observation of a high-energy neutrino error box of which the variability was discovered after high-energy-neutrino detection. The one...

The origin of high-energy emission in blazars jets (i.e., leptonic versus hadronic) has been a longstanding matter of debate. Here, we focus on one variant of hadronic models...

In order to study short timescale optical variability of {gamma}-ray blazar S5 0716+714, quasi-simultaneous spectroscopic and multiband photometric observations were performed...

The recently published fourth Fermi Large Area Telescope source catalog (4FGL) reports 5065 gamma-ray sources in terms of direct observational gamma-ray properties. Among the...

The relationship between galaxies and the state/chemical enrichment of the warm-hot intergalactic medium (WHIM) expected to dominate the baryon budget at low-z provides...

The typical blazar S5 0716+714 is very interesting due to its rapid and large-amplitude variability and high duty cycle of microvariability in the optical band. We analyze the...

Even with several thousand Fermi-Large Area Telescope (LAT) blazar detections, the {gamma}-ray emission mechanism is poorly understood. We explore correlated optical/{gamma}-ray...

X-ray polarization should provide new probes of magnetic field geometry and acceleration physics near the base of blazar jets, but near-future missions will have limited...

We present the photometric observations of blazars S5 0716+714 and 3C 273 with high temporal resolution (30-60s) in the I or R bands. The observations were performed with a...

We present results from a parsec-scale jet kinematics study of 409 bright radio-loud active galactic nuclei (AGNs) based on 15GHz Very Long Baseline Array (VLBA) data obtained...

We report a novel radio autocorrelation search for extraterrestrial intelligence. For selected frequencies across the terrestrial microwave window (1-10GHz), observations were...

We report the identification of blazar candidates behind the Magellanic Clouds. The objects were selected from the Magellanic Quasars Survey (MQS), which targeted the entire...

Relativistic effects dominate the emission of blazar jets complicating our understanding of their intrinsic properties. Although many methods have been proposed to account for...

Detection of the IceCube-170922A neutrino coincident with the flaring blazar TXS 0506+056, the first and only ~3{sigma} high-energy neutrino source association to date, offers a...

We have obtained a smooth time series for the electric vector position angle (EVPA) of the blazar OJ 287 at centimeter wavelengths, by making +/-n{pi} adjustments to archival...

We report on 16 BL Lacertae objects that were proposed to be at z>1. We present spectroscopic observations secured at the 10.4m GTC that allowed us to assess the redshift of...

We present the results from a detailed spectral and timing study of Mrk 421 based on the rich archival Swift data obtained during 2009-2012. Best fits of the 0.3-10keV spectra...

We present detailed results of Swift observations of the nearby TeV-detected blazar Mrk 421, based on the rich archival data obtained during 2005 March-2008 June. The best fits...