Discovery of a wandering radio jet base after a large X-ray flare in the blazar Markarian 421

Abstract

We investigate the location of the radio jet bases ("radio cores") of blazars in radio images, and their stationarity by means of dense very long baseline interferometry (VLBI) observations. In order to measure the position of a radio core, we conducted 12 epoch astrometric observation of the blazar Markarian 421 with the VLBI Exploration of Radio Astrometry at 22 GHz immediately after a large X-ray flare, which occurred in the middle of 2011 September. For the first time, we find that the radio core is not stationary but rather changes its location toward 0.5 mas downstream. This angular scale corresponds to the de-projected length of a scale of $10^5$ Schwarzschild radii (Rs) at the distance of Markarian~421. This radio-core wandering may be a new type of manifestation associated with the phenomena of large X-ray flares.

arXiv comment6 pages, 4 figures, 1 table, has been published in ApJ Letters

References in corpus (27)

• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• Structured jets in TeV BL Lac objects and radiogalaxies
• MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. VI. Kinematics Analysis of a Complete Sample of Blazar Jets
• Probing the Inner Jet of the Quasar PKS 1510-089 with Multi-waveband Monitoring during Strong Gamma-ray Activity
• MOJAVE. X. Parsec-Scale Jet Orientation Variations and Superluminal Motion in AGN
• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei III. Kinematics of Parsec-Scale Radio Jets
• Internal shocks in the jets of radio-loud quasars
• A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279
• Radio Imaging of the Very-High-Energy Gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
• Alignment of Magnetized Accretion Disks and Relativistic Jets with Spinning Black Holes
• Innermost collimation structure of the M87 jet down to ~ten Schwarzschild radii
• The Jets of TeV Blazars at Higher Resolution: 43 GHz and Polarimetric VLBA Observations from 2005-2009
• Studies of the Jet in BL Lacertae I. Recollimation Shock and Moving Emission Features
• Radio and gamma-ray follow-up of the exceptionally high activity state of PKS 1510-089 in 2011
• Synoptic studies of seventeen blazars detected in very high-energy gamma-rays
• A strong radio brightening at the jet base of M87 during the elevated very-high-energy gamma-ray state in 2012
• Detection of jet precession in the active nucleus of M81
• VLBA monitoring of Mrk 421 at 15 GHz and 24 GHz during 2011
• Synchrotron and inverse-Compton emission from blazar jets - IV. BL Lac type blazars and the physical basis for the blazar sequence
• Very Long Baseline polarimetry and the gamma-ray connection in Markarian 421 during the broadband campaign in 2011
• The TeV blazar Markarian 421 at the highest spatial resolution
• On the location of the supermassive black hole in CTA 102
• Charge-starved, relativistic jets and blazar variability
• Probing the central black hole in M87 with gamma-rays
• Possible Detection of Apparent Superluminal inward motion in Markarian 421 after the Giant X-ray flare in February, 2010
• On invisible plasma content in radio-loud AGNs: The case of TeV blazar Markarian 421

Cited by in corpus (12)

• Significant core shift variability in parsec-scale jets of active galactic nuclei
• Precise radio astrometry and new developments for the next generation of instruments
• A connection between $\gamma$-ray and parsec-scale radio flares in the blazar 3C 273
• A parsec-scale wobbling jet in the high-synchrotron peaked blazar PG 1553+113
• Ejection of Double knots from the radio core of PKS 1510--089 during the strong gamma-ray flares in 2015
• Interferometric Monitoring of Gamma-ray Bright AGNs: OJ 287
• Discovery of off-axis jet structure of TeV blazar Mrk 501 with mm-VLBI
• Time variability of the core-shift effect in the blazar 3C 454.3
• Very-long-baseline interferometry study of the flaring blazar TXS 1508+572 in the early Universe
• Jet Archaeology and Forecasting: Image Variability and Magnetic Field Configuration
• The dynamics of the parsec-scale jet in the neutrino blazar PKS 0735+178
• Opacity effect on core-shift and the spectral properties of jets