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Abraham, Tamas; Roddick, John F.

doi:10.1023/a:1009800916313

Cited by 208 publications

(84 citation statements)

References 49 publications

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“…In the following, we will explore some possible scenarios that could lie behind the observed curving structure, and discuss the observational evidence for and against them. There is one important difference between our data and that used by Abraham & Romero (1999) to construct their model. Most observations cited in their paper were carried out at lower frequencies (mainly 10.7 GHz) with significantly poorer resolution.…”

Section: Discussionmentioning

confidence: 96%

“…15 we have plotted the apparent velocities and directions of motion for three prominent components in the tapered data as a function of their ejection epochs. We have also included the data from Abraham & Romero (1999), scaled to the cosmology used in this paper, and superimposed their precession model to the figure. As can be seen, we cannot exclude the possibility that the average jet direction changes periodically, and that it can be approximately described by the Abraham & Romero model.…”

Section: Discussionmentioning

confidence: 99%

“…Its position at the last epoch deviates ∼0.11 mas from the straight line path extrapolated from the first three epochs and it does not follow the path taken earlier by components B3−B5. Follow-up observations tracking the motion of C1 will show if the bending continues and C1 becomes a "northern component" with a Abraham & Romero (1999) with β app scaled to the cosmology used in this paper, and our 43 GHz data tapered to a resolution corresponding to observations made at 10.7 GHz. The solid curves represent the precession model of Abraham & Romero (1999).…”

Section: Ballistic or Not?mentioning

confidence: 99%

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Multifrequency VLBA monitoring of 3C 273 during the INTEGRAL Campaign in 2003

Savolainen¹,

Wiik

Valtaoja

et al. 2006

A&A

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In this first of a series of papers describing polarimetric multifrequency Very Long Baseline Array (VLBA) monitoring of 3C 273 during a simultaneous campaign with the INTEGRAL γ-ray satellite in 2003, we present 5 Stokes I images and source models at 7 mm. We show that a part of the inner jet (1−2 milliarcsec from the core) is resolved in a direction transverse to the flow, and we analyse the kinematics of the jet within the first 10 mas. Based on the VLBA data and simultaneous single-dish flux density monitoring, we determine an accurate value for the Doppler factor of the parsec scale jet, and using this value with observed proper motions, we calculate the Lorentz factors and the viewing angles for the emission components in the jet. Our data indicates a significant velocity gradient across the jet with the components travelling near the southern edge being faster than the components with more northern path. We discuss our observations in the light of jet precession model and growing plasma instabilities.

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Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 99%

Section: Ballistic or Not?mentioning

confidence: 99%

See 1 more Smart Citation

Multifrequency VLBA monitoring of 3C 273 during the INTEGRAL Campaign in 2003

Savolainen¹,

Wiik

Valtaoja

et al. 2006

A&A

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“…Moreover, the same basic mechanism might work even in AGNs if a binary system of supermassive black holes is located at the center of a galaxy that underwent a recent merger. In case the accretion disk is not aligned with the orbital plane, the gravitational pull of the secondary black hole would trigger a precession that might modulate the superluminal ejections of plasmons (e.g., Abraham & Romero 1999) and produce periodic variability on timescales of years (Romero Spectral energy distribution of the radiation produced by a Wolf-Rayet star interacting with a relativistic jet of a Faranoff-Riley I radio galaxy (Araudo et al 2013(Araudo et al ). et al2000, in comparison with the much longer timescales of the Bardeen-Peterson effect (see Bicknell contribution to these proceedings).…”

Section: Binaritymentioning

confidence: 99%

Synergies in extragalactic and Galactic jet research

Romero¹

2014

Proc. IAU

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The discovery of relativistic jets and superluminal sources associated with accreting X-ray binaries in the Galaxy opened new ways of investigating the physics of outflows from compact objects. The short timescales and relatively large angular sizes of Galactic jets allow to probe the physics of relativistic outflows to unprecedented details. In this article I discuss results of recent modelling of Galactic jets, covering both radiative and dynamical aspects, which can shed light on different features of their extragalactic cousins.Comment: 9 pages, 7 figures. To appear in the Proceedings of the IAU Symposium No. 313: "Extragalactic jets from every angle", Galapagos, Ecuador, 15-19 September 2014, F. Massaro, C. C. Cheung, E. Lopez, and A. Siemiginowska (Eds.), Cambridge University Pres

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“…In these databases, special implementation techniques should be developed for efficient storage and access of spatial objects, their geometric representations and their time-varying characteristics. Reference [1] is an excellent survey on the advances made during the last years, in spatio-temporal database research.…”

Section: Introductionmentioning

confidence: 99%

Multiversion Linear Quadtree for Spatio-Temporal Data

Tzouramanis

Vassilakopoulos

Manolopoulos

2001

Current Issues in Databases and Information Systems

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Abstract. Research in spatio-temporal databases has largely focused on extensions of access methods for the proper handling of time changing spatial information. In this paper, we present the Multiversion Linear Quadtree (MVLQ), a spatio-temporal access method based on Multiversion B-trees (MVBT) [2], embedding ideas from Linear Region Quadtrees [4]. More specifically, instead of storing independent numerical data having a different transaction-time each, for every consecutive image we store a group of codewords that share the same transaction-time, whereas each codeword represents a spatial subregion. Thus, the new structure may be used as an index mechanism for storing and accessing evolving raster images. We also conducted a thorough experimentation using sequences of real and synthetic raster images. In particular, we examined the time performance of temporal window queries, and provide results for a variety of parameter settings.

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Cited by 208 publications

References 49 publications

Multifrequency VLBA monitoring of 3C 273 during the INTEGRAL Campaign in 2003

Multifrequency VLBA monitoring of 3C 273 during the INTEGRAL Campaign in 2003

Synergies in extragalactic and Galactic jet research

Multiversion Linear Quadtree for Spatio-Temporal Data

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