Relativistic models of two low-luminosity radio jets: B2 0326+39 and B2 1553+24

Abstract

We apply the intrinsically symmetrical, decelerating relativistic jet model developed by Laing & Bridle for 3C 31 to deep, full-synthesis 8.4-GHz VLA imaging of the two low-luminosity radio galaxies B2 0326+39 and B2 1553+24. After some modifications to the functional forms used to describe the geometry, velocity, emissivity and magnetic-field structure, these models can accurately fit our data in both total intensity and linear polarization. We conclude that the jets in B2 0326+39 and B2 1553+24 are at angles of 64 +/- 5 deg and 7.7 +/- 1.3 deg to the line of sight, respectively. In both objects, we find that the jets decelerate from 0.7 - 0.8c to <0.2c over a distance of approximately 10 kpc, although in B2 1553+24 this transition occurs much further from the nucleus than in B2 0326+39 or 3C 31. The longitudinal emissivity profiles can be divided into sections, each fit accurately by a power law; the indices of these power laws decrease with distance from the nucleus. The magnetic fields in both objects are dominated by the longitudinal component in the high-velocity regions close to the nucleus and by the toroidal component further out, but B2 0326+39 also has a significant radial component at large distances, whereas B2 1553+24 does not. Simple adiabatic models fail to fit the emissivity variations in the regions of high velocity but provide good descriptions of the emissivity after the jets have decelerated. Given the small angle to the line of sight inferred for B2 1553+24, there should be a significant population of similar sources at less extreme orientations. Such objects should have long (>200 kpc), straight, faint jets and we show that their true sizes are likely to have been underestimated in existing images. (Slightly abridged.)

arXiv comment27 pages, 21 figures, accepted for publication in MNRAS

References in corpus (13)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• VLBI Observations of a Complete Sample of Radio Galaxies. 10 Years Later
• Dynamical models for jet deceleration in the radio galaxy 3C 31
• Relativistic models and the jet velocity field in the radio galaxy 3C 31
• On the Relationship between BL-Lacertae Objects and FRI Radio Galaxies
• A Chandra observation of the X-ray environment and jet of 3C31
• X-ray-emitting Atmospheres of B2 Radio Galaxies
• X-ray observations of low-power radio galaxies from the B2 catalogue
• Adiabatic relativistic models for the jets in the radio galaxy 3C 31
• The jets in 3C 296
• The HST survey of the B2 sample of radio galaxies: detection of two optical jets
• Synchrotron emission from anisotropic disordered magnetic fields
• Redshifts for a Sample of Radio-Selected Poor Clusters

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