Variability and Proper Motion of X-ray Knots in the Jet of Centaurus A

Abstract

We report results from Chandra observations analyzed for evidence of variability and proper motion in the X-ray jet of Centaurus A. Using data spanning 15 years, collective proper motion of $11.3\pm 3.3$ mas yr${}^{-1}$, or $0.68\pm 0.20c$, is detected for the fainter X-ray knots and other substructure present within the jet. The three brightest knots (AX1A, AX1C, and BX2) are found to be stationary to an upper limit of $0.10c$. Brightness variations up to 27% are detected for several X-ray knots in the jet. For the fading knots, BX2 and AX1C, the changes in spectral slope expected to accompany synchrotron cooling are not found, ruling it out and placing upper limits of $\simeq 80\mu \mathrm{G}$ for each of their magnetic field strengths. Adiabatic expansion can account for the observed decreases in brightness. Constraints on models for the origin of the knots are established. Jet plasma overrunning an obstacle is favored as the generator of stationary knots, while moving knots are likely produced either by internal differences in jet speed or the late stages of jet interaction with nebular or cloud material.

arXiv commentAccepted to ApJ, 14 pages, 8 figures, 2 tables

References in corpus (43)

• On Uncertainties in Cross-Correlation Lags and the Reality of Wavelength-Dependent Continuum Lags in Active Galactic Nuclei
• MOJAVE. X. Parsec-Scale Jet Orientation Variations and Superluminal Motion in AGN
• The Structure and Dynamics of the Sub-parsec Scale Jet in M87 Based on 50 VLBA Observations Over 17 Years at 43 GHz
• VLBI Observations of a Complete Sample of Radio Galaxies. 10 Years Later
• Kinematics of the jet in M87 on scales of 100 -- 1000 Schwarzschild radii
• A High Resolution X-ray Image of the Jet in M 87
• Radio and X-ray observations of the jet in Centaurus A
• The Distance to NGC 5128 (Centaurus A)
• Dynamical models for jet deceleration in the radio galaxy 3C 31
• From the Blazar Sequence to the Blazar Envelope: Revisiting the Relativistic Jet Dichotomy in Radio-loud AGN
• On the Relationship between BL-Lacertae Objects and FRI Radio Galaxies
• High-Sensitivity 86GHz (3.5mm) VLBI Observations of M87: Deep Imaging of the Jet Base at a 10 Schwarzschild-Radius Resolution
• High-energy particle acceleration at the radio-lobe shock of Centaurus A
• Chandra observations of the X-ray jet in 3C66B
• Limb-Brightened Jet of 3C 84 Revealed by the 43-GHz Very-Long-Baseline-Array Observation
• Chandra Observations of the X-ray Jet in Centaurus A
• Chandra finds X-ray jets are common in low-power radio galaxies
• Discovery of Sub- to Superluminal Motions in the M87 Jet: An Implication of the Acceleration from Sub-relativistic to Relativistic Speeds
• On the deceleration of FRI jets: mass loading by stellar-winds
• New results on particle acceleration in the Centaurus A jet and counterjet from a deep Chandra observation
• TANAMI monitoring of Centaurus A: The complex dynamics in the inner parsec of an extragalactic jet
• Radio observations of active galactic nuclei with mm-VLBI
• Mass entrainment and turbulence-driven acceleration of ultra-high energy cosmic rays in Centaurus A
• How old are the stars in the halo of NGC 5128 (Centaurus A)?
• Ruling out IC/CMB X-rays in PKS 0637-752 and the Implications for TeV Emission from Large-Scale Quasar Jets
• Internal entrainment and the origin of jet-related broad-band emission in Centaurus A
• The X-ray Jet in Centaurus A: Clues on the Jet Structure and Particle Acceleration
• Optical Proper Motion Measurements of the M87 Jet: New Results from the Hubble Space Telescope
• The Cocoon Shocks of Cygnus A: Pressures and Their Implications for the Jets and Lobes
• Fermi Rules Out the IC/CMB Model for the Large Scale Jet X-ray Emission of 3C 273
• Long Term Monitoring of the Dynamics and Particle Acceleration of Knots in the Jet of Centaurus A
• A relativistic model of the radio jets in NGC 315
• Fermi non-detections of four X-ray jet sources and implications for the IC/CMB mechanism
• The infrared jet in Centaurus A: multiwavelength constraints on emission mechanisms and particle acceleration
• A Parsec Scale Accelerating Radio Jet in the Giant Radio Galaxy NGC315
• X-ray variability in M87
• Where Centaurus A gets its X-ray knottiness
• The Complex North Transition Region of Centaurus A: A Galactic Wind
• Numerical simulations of shocks encountering clumpy regions
• The jet and counterjet of 3C 270 (NGC 4261) viewed in the X-ray with Chandra
• Relativistic models of two low-luminosity radio jets: B2 0326+39 and B2 1553+24
• Parsec-scale shocks in the kiloparsec-scale jet of Centaurus A
• Optical Detection of the Pictor A Jet and Tidal Tail: Evidence against an IC/CMB jet

Cited by in corpus (21)

• Particle acceleration in astrophysical jets
• Resolving acceleration to very high energies along the Jet of Centaurus A
• Detection of Superluminal Motion in the X-Ray Jet of M87
• Particle acceleration in shearing flows: the self-generation of turbulent spine-sheath structures in relativistic MHD jet simulations
• Active Galactic Nuclei as potential Sources of Ultra-High Energy Cosmic Rays
• Blazars at Very High Energies: Emission Modelling
• Particle acceleration in shearing flows: the case for large-scale jets
• Offsets between X-ray and Radio Components in X-ray Jets: The AtlasX
• Discovery of Candidate X-ray Jets in High-Redshift Quasars
• The multi-phase environment in the centre of Centaurus A
• A 1D fluid model of the Centaurus A jet
• X-Ray-to-Radio Offset Inference from Low-Count X-Ray Jets
• Variability of extragalactic X-ray jets on kiloparsec scales
• Non-thermal emission resulting from a supernova explosion inside an extragalactic jet
• The Advanced X-ray Imaging Satellite
• Physical Conditions and Particle Acceleration in the Kiloparsec Jet of Centaurus A
• Astrophysical Evidence of Wakefield Acceleration in Galactic and Extragalactic Jets via Gamma Rays and UHECRs
• An Analysis of Soft X-ray Structures at Kiloparsec Distances from the Active Nucleus of Centaurus A Galaxy
• The origin of the very-high-energy radiation along the jet of Centaurus A
• Proper Motions in the sub-kiloparsec Jet of 3C 78: Novel Constraints on the Physical Nature of Relativistic Jets
• Distributed accelerators in the jet of Centaurus A: the origin of the spectral hardening of very high energy gamma-rays