Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Multi-band Study of the remarkable Jet in Quasar 4C+19.44   We present arc-second-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
arc-second angular resolution at three frequencies, plus HST and Spitzer data.
The Chandra data allow us to measure the X-ray spectral index in 10 distinct
regions along the 18 arcsec 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 in the
direction of the unseen counter jet and coincident with the northern radio
lobe. This jet is remarkable since 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.

19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics