University of Hertfordshire

From the same journal

From the same journal

By the same authors

A high-resolution view of the jets in 3C 465

Research output: Contribution to journalArticlepeer-review


  • 2005.11403v1

    Accepted author manuscript, 1.14 MB, PDF document

  • E. Bempong-Manful
  • M. J. Hardcastle
  • Mark Birkinshaw
  • R. A. Laing
  • J. P. Leahy
  • D. M. Worrall
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Original languageEnglish
Article numberstaa1471
JournalMonthly Notices of the Royal Astronomical Society
Early online date28 May 2020
Publication statusE-pub ahead of print - 28 May 2020


We present new high-resolution and high-sensitivity studies of the jets in the WAT source 3C 465, using deep transverse-resolved radio observations from e-MERLIN, and with complementary observations from the VLA. We derive a lower limit $\beta_{\rm j}$ = ($\nu_{\rm j}$/$c$) $\gtrsim$ 0.5 for the jet speed, and an upper limit $\theta_{\rm j}$ $\lesssim$ 61$^{\circ}$ for the jet angle to the line of sight. The jet spectral index ($\alpha$, defined in the sense $S \propto \nu^{\alpha}$) is fairly constant ( = $-$0.7), and spectral flattening within 4.4 kpc of the core coincides with bright knots and is consistent with the site of X-ray particle acceleration at the base of the radio jet found in previous studies. There is little difference between the spectra of the two hotspot components, plausibly indicating that electron populations of the same properties are injected there. The NW and SE plumes are approximately homologous structures, with variations in mass injection and propagation in external pressure and density gradients in the two regions plausibly accounting for the slightly steeper spectrum in the NW plume, = $-$1.43 compared with the SE plume, = $-$1.38. Our synchrotron lifetime model supports plausible reacceleration of particles within the plume materials. Overall, our results show that the first-order Fermi process at mildly relativistic and non-relativistic shocks is the most likely acceleration mechanism at play in 3C 465 and distinguish differences between the acceleration at $\beta_{\rm j}$ $>$ 0.5 and $\beta_{\rm j}$ $


This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.


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