Superluminal non-ballistic jet swing in the quasar NRAO 150 revealed by mm-VLBI

Agudo, I.; Bach, U.; Krichbaum, T. P.; Marscher, A. P.; Gonidakis, I.; Diamond, P. J.; Perucho, M.; Alef, W.; Graham, D. A.; Witzel, A.; Zensus, J. A.; Bremer, M.; Acosta–Pulido, J. A.; Barrena, R.

doi:10.1051/0004-6361:20078448

Cited by 81 publications

(115 citation statements)

References 28 publications

(36 reference statements)

Supporting

Mentioning

109

Contrasting

Order By: Relevance

“…Jet rotation has so far not been directly detected in AGN jets, with the reported rotational speeds clearly related to the rotation of patterns inside the flow (e.g. Lobanov et al 2003;Agudo et al 2007Agudo et al , 2012Cohen et al 2015) resulting from plasma instability in the flow. If our measured rotation is associated with conserved angular momentum in the jet and if the jet is launched from the accretion disk via the BP mechanism, its direction should be the same as the rotational direction of the disk itself.…”

Section: Interpretation Of the Jet Rotationmentioning

confidence: 99%

Kinematics of the jet in M 87 on scales of 100–1000 Schwarzschild radii

Mertens

Lobanov

Walker

et al. 2016

A&A

226

266

View full text Add to dashboard Cite

Context. Very long baseline interferometry (VLBI) imaging of radio emission from extragalactic jets provides a unique probe of physical mechanisms governing the launching, acceleration, and collimation of relativistic outflows. Aims. VLBI imaging of the jet in the nearby active galaxy M 87 enables morphological and kinematic studies to be done on linear scales down to ∼ 100 Schwarzschild radii (R s ). Methods. The two-dimensional structure and kinematics of the jet in M 87 (NGC 4486) have been studied by applying the Waveletbased Image Segmentation and Evaluation (WISE) method to 11 images obtained from multi-epoch Very Long Baseline Array (VLBA) observations made in January-August 2007 at 43 GHz (λ = 7 mm).Results. The WISE analysis recovers a detailed two-dimensional velocity field in the jet in M 87 at sub-parsec scales. The observed evolution of the flow velocity with distance from the jet base can be explained in the framework of MHD jet acceleration and Poynting flux conversion. A linear acceleration regime is observed up to z obs ∼ 2 mas. The acceleration is reduced at larger scales, which is consistent with saturation of Poynting flux conversion. Stacked cross correlation analysis of the images reveals a pronounced stratification of the flow. The flow consists of a slow, mildly relativistic layer (moving at β ∼ 0.5 c), associated either with instability pattern speed or an outer wind, and a fast, accelerating stream line (with β ∼ 0.92, corresponding to a bulk Lorentz factor γ ∼ 2.5). A systematic difference of the apparent speeds in the northern and southern limbs of the jet is detected, providing evidence for jet rotation. The angular velocity of the magnetic field line associated with this rotation suggests that the jet in M87 is launched in the inner part of the disk, at a distance r 0 ∼ 5 R s from the central engine.Conclusions. The combined results of the analysis imply that MHD acceleration and conversion of Poynting flux to kinetic energy play the dominant roles in collimation and acceleration of the flow in M 87.

show abstract

Section: Interpretation Of the Jet Rotationmentioning

confidence: 99%

Kinematics of the jet in M 87 on scales of 100–1000 Schwarzschild radii

Mertens

Lobanov

Walker

et al. 2016

A&A

226

266

View full text Add to dashboard Cite

show abstract

“…4 observations were taken from the CJF-survey (Britzen et al 2007). S5 0716+714 was used as calibrator source for observations targeted at NRAO 150 (Agudo et al 2007) in 6 epochs. Part of the data presented here have already been analyzed and discussed by Bach et al (2005).…”

Section: Introductionmentioning

confidence: 99%

Non-radial motion in the TeV blazar S5 0716+714

Britzen¹,

Kam²,

Witzel³

et al. 2009

A&A

Self Cite

View full text Add to dashboard Cite

Context. Flat-spectrum radio sources often show a core-jet structure on pc-scales. Individual jet components reveal predominantly outward directed motion. For the BL Lac object S5 0716+714 conflicting apparent velocities have been reported in the literature. This object is an intra-day variable source and suited to investigate a possible correlation between kinematic properties and flux-density variability on different timescales. Aims. We study the kinematics in the pc-scale jet of S5 0716+714 to determine the apparent speeds of the jet components based on a much improved data set. In addition, we search for correlations between the radio flux-density light curves and the morphological changes detected along the VLBI jet. Methods. We (re-)analyze 50 VLBI observations obtained with the VLBA at 5 different frequencies (5-43 GHz) between 1992.73 and 2006.32. The data have been parameterized using circular Gaussian components. We analyze the jet component motion in detail taking care not only to account for motion in the radial but also in the orthogonal direction. We study the evolution of the jet ridge line and investigate the spectral properties of the individual components. We search for correlations between radio band light curves and the kinematic properties of the jet components. Results. We present an alternative kinematic scenario for jet component motion in S5 0716+714. We present evidence for the apparent stationarity of jet components (with regard to their core separation) with time. Jet components, however, do seem to move significantly non-radially with regard to their position angle and in a direction perpendicular to the major axis of the jet. We discuss a possible correlation between the long-term radio flux-density variability and apparent jet component motions. Conclusions. In S5 0716+714 an alternative motion scenario is proposed. With regard to the core separation, rather stationary components can fit the VLBI observations well. A new model to explain the observed motion with regard to the position angle is required. Based on the correlation between the longterm radio flux-density variability and the position angle evolution of a jet component, we conclude that a geometric contribution to the origin of the long-term variability might not be negligible. Subluminal motion has been reported for most of the TeV blazars. Our analysis also confirms this finding for the case of S5 0716+714. This result increases the number of TeV blazars showing apparent subluminal motion to 7.

show abstract

“…There has also been evidence of rapid "jet wobbling" at ∼11 • /yr in the plane of the sky, which is the most rapid for an AGN found so far. The observations by Agudo et al (2007) together with the cosmological redshift measurement presented in this paper and non-contemporaneous X-ray data have allowed them to report the first quantitative estimates of the basic physical properties of the inner jet in NRAO 150, i.e., Doppler factor δ ≈ 6, the bulk Lotentz factor γ ≈ 4, the angle subtended between the jet and the line of sight φ ≈ 8 • , and the magnetic field intensity of the flow B ≈ 0.7 G. This high B estimate seems to be compatible with the highly non-balistic superluminal motion of the inner jet in the source detected by the mm-VLBI images (β app ≈ 3 times the speed of light), which have also demonstrated that NRAO 150 is a prime target for studying the origin of the jet wobbling phenomenon (Agudo 2009). …”

Section: Introductionmentioning

confidence: 95%

“…The X-ray data, acquired by ROSAT from August 1990 and February 1991, were corrected by Galactic extinction as reported in Agudo et al (2007). For the plot in Fig.…”

Section: The Spectral Energy Distributionmentioning

confidence: 99%

“…The first set of ultra-high-resolution mm-VLBI images of NRAO 150 (Agudo et al 2007) allowed them to detect a large misalignment (>100 • ) between the cm-wave and the mm-wave jet, which in addition to the one sidedness of the jet, is a clear sign of jet orientation close to the line of sight. There has also been evidence of rapid "jet wobbling" at ∼11 • /yr in the plane of the sky, which is the most rapid for an AGN found so far.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The redshift and broad-band spectral energy distribution of NRAO 150

Acosta–Pulido

Agudo

Barrena

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

Context. NRAO 150 is one of the brightest radio and mm AGN sources in the northern sky, and is an interesting source to study extreme relativistic jet phenomena. However, its cosmological distance has not yet been calibrated, because of its optical faintness due to strong Galactic extinction. Aims. We measure the redshift of NRAO 150, to enable us to perform quantitative studies of the source. Methods. We conducted spectroscopic and photometric observations of the source in both the near-IR and the optical. Results. All these observations were successful in detecting the source. The near-IR spectroscopic observations exhibit strong Hα and Hβ emission lines from which the cosmological redshift of NRAO 150 (z = 1.517 ± 0.002) is determined for the first time. We classify the source as a flat-spectrum radio-loud quasar, for which we estimate a high supermassive black-hole mass ∼5 × 10 9 M . After extinction correction, the new near-IR and optical data show a high-luminosity continuum-emission excess in the optical (peaking in the rest frame at ∼2000 Å) that we attribute to thermal emission from the accretion disk for which we estimate a high accretion rate of ∼30% the Eddington limit. Conclusions. Comparison of the source properties and its broad-band spectral-energy distribution with those of Fermi blazars allows us to predict that NRAO 150 is among the most powerful of blazars, and hence a high luminosity -although not yet detected -γ-ray emitter.

show abstract

Superluminal non-ballistic jet swing in the quasar NRAO 150 revealed by mm-VLBI

Cited by 81 publications

References 28 publications

Kinematics of the jet in M 87 on scales of 100–1000 Schwarzschild radii

Kinematics of the jet in M 87 on scales of 100–1000 Schwarzschild radii

Non-radial motion in the TeV blazar S5 0716+714

The redshift and broad-band spectral energy distribution of NRAO 150

Contact Info

Product

Resources

About