The long-term evolution of the parsec scale jet of the quasar 3C345

Abstract

Abstract. The quasar 3C 345 is one of the best examples of an active galactic nucleus (AGN) showing structural and flux variability on parsec scales around a compact unresolved radio core. Over the past 30 years, it has been followed up closely from radio to gamma-ray wavebands with a special focus on very long baseline interferometry (VLBI) observations in the range of 1-100 GHz. The complex parsec-scale jet of 3C 345 exemplifies an archetypical 'superluminal' jet with an apparent helical morphology. Here we present first results from a study of the long-term jet evolution, especially focusing on the evolution of trajectories, kinematics, and emission in more than 20 enhanced emission regions embedded in the jet. A "closeup" on physical properties of individual features implies that the outer jet is most likely dominated by Kelvin-Helmholtz instability. Studies of general trends in properties of those features provide certain evidence for their apparent trajectories to result from an underlying (slowly evolving) pattern lit up by passages of plasma condensations ejected during the nuclear flares. The long-term evolution of this pattern indicates its possible relation either to the elliptical mode of Kelvin-Helmholtz instability or precession of the jet direction.

Radiative signatures of the relativistic Kelvin-Helmholtz instability

“…The Kelvin-Helmholtz instability (KHI) is one of the fundamental instabilities observed in plasmas. Originally studied in fluids [62,61], the plasma KHI nowadays plays an important role in such diverse fields as Astrophysics [22,57,54], Space Physics [35,39], Solar Physics [17,40,19], Planetary Physics [51,13], Fusion Research [9,53], and Laser-Plasma Physics [30,34,55].…”

Possible evidence for double precessing nozzle structure in QSO 3C345

“…3C345 (z=0.595) is an archetypal quasar and one of the best-studied blazars (e.g., Biretta et al 1986, Hardee et al 1987, Homan et al 2014, Jorstad et al 2005, 2013, Klare 2003, Klare et al 2005, Lobanov & Roland 2005, Qian et al 1991a, 2009, Schinzel et al 2010a, Schinzel 2011a, Schinzel et al 2011b, 2011c, Steffen et al 1996, Unwin et al 1997, Zensus et al 1997. Its emission spreads over the entire electromagnetic spectrum, from radio, IR, optical, UV, X-ray to high-energy γ-rays.…”

“…This phenomenon may be very important for understanding the properties of the central energy engine in its nucleus. The VLBI-kinematics of superluminal components in 3C345 has been analyzed by Schinzel (2011a) for a ∼30 years period, showing no trend for jet-precession. In this paper we investigate the VLBI-kinematics of 3C345 extending to ∼38 yr timeinterval, yielding some new significant results.…”

“…Sillanpää et al 1988, Babadzhanyants et al 1995, Kudryavtseva et al2006, Qian et al 2007) are important and could provide key information on the nature of the central engine in blazars. The position angle swings of superluminal components on parsec-scales observed by VLBI-monitoring observations could be used to search for periodicities in ejection of superluminal knots (e.g., Britzen et al 2001, Tateyama & Kingham 2004, Klare 2005, Schinzel et al 2012b, Qian et al 2009). In the case of QSO 3C345 and based on the position angle swing of its superluminal components, some authors argued for the existence of a jet precessing period: e.g., ∼8-10 yr (Lobanov & Zensus 1999, Klare et al 2005, Klare 2003), ∼9.5 yr (Lobanov & Roland 2005).…”

Szupernagy tömegű fekete lyuk kettősökre utaló jelek rádió-hangos aktív galaxismagok jeteiben

“…Így a beam-mérete θ = √ θ 2 min + θ 2 max . Ekkor az integrált fluxussűrűség hibáját megadhatjuk a következő módon [186]: ahol SN R = S p /σ p a jel/zaj arány. A komponens-méret hibája :…”