Skip to main content

Research Repository

Advanced Search

A Multi-band Study of the Remarkable Jet in Quasar 4C+19.44

Harris, D.E.; Lee, N.P.; Schwartz, D.A.; Siemiginowska, A.; Massaro, F.; Birkinshaw, M.; Worrall, D.M.; Cheung, C.C.; Gelbord, J.M.; Jorstad, Svetlana G.; Marscher, Alan P.; Landt, H.; Marshall, H.; Perlman, E.S.; Stawarz, L.; Uchiyama, Y.; Urry, C.M.

A Multi-band Study of the Remarkable Jet in Quasar 4C+19.44 Thumbnail


D.E. Harris

N.P. Lee

D.A. Schwartz

A. Siemiginowska

F. Massaro

M. Birkinshaw

D.M. Worrall

C.C. Cheung

J.M. Gelbord

Svetlana G. Jorstad

Alan P. Marscher

H. Landt

H. Marshall

E.S. Perlman

L. Stawarz

Y. Uchiyama

C.M. Urry



We present arcsecond-resolution data in the radio, IR, optical, and X-ray for 4C+19.44 (=PKS 1354+195), the longest and straightest quasar jet with deep X-ray observations. We report results from radio images with half to one arcsecond angular resolution at three frequencies, plus Hubble Space Telescope and Spitzer data. The Chandra data allow us to measure the X-ray spectral index in 10 distinct regions along the 18'' jet and compare with the radio index. The radio and X-ray spectral indices of the jet regions are consistent with a value of $\alpha =0.80$ throughout the jet, to within $2\sigma $ uncertainties. The X-ray jet structure to the south extends beyond the prominent radio jet and connects to the southern radio lobe, and there is extended X-ray emission, both in the direction of the unseen counter-jet, and also coincident with the northern radio lobe. This jet is remarkable because its straight appearance over a large distance allows the geometry factors to be taken as fixed along the jet. Using the model of inverse Compton scattering of the cosmic microwave background (iC/CMB) by relativistic electrons, we find that the magnetic field strengths and Doppler factors are relatively constant along the jet. If instead the X-rays are synchrotron emission, they must arise from a population of electrons distinct from the particles producing the radio synchrotron spectrum.


Harris, D., Lee, N., Schwartz, D., Siemiginowska, A., Massaro, F., Birkinshaw, M., …Urry, C. (2017). A Multi-band Study of the Remarkable Jet in Quasar 4C+19.44. Astrophysical Journal, 846(2), Article 119.

Journal Article Type Article
Acceptance Date Aug 3, 2017
Online Publication Date Sep 8, 2017
Publication Date Sep 8, 2017
Deposit Date Oct 10, 2017
Publicly Available Date Oct 10, 2017
Journal Astrophysical Journal
Print ISSN 0004-637X
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 846
Issue 2
Article Number 119


Published Journal Article (3.5 Mb)

Publisher Licence URL

Copyright Statement
Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

You might also like

Downloadable Citations