Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sub-arcsecond imaging and spectroscopy of the radio-loud highly
  polarized quasar PKS 1610-771   We report on imaging and spectroscopic observations of the radio-loud, highly
polarized quasar PKS 1610-771 (z = 1.71). Our long-slit spectroscopy of the
companion 4.55 arcseconds NW of the quasar confirms the stellar nature of this
object, so ruling out the previously suspected gravitationally lensed nature of
this system. PKS 1610-771 looks fuzzy on our sub-arcsecond R and I images and
appears located in a rich environment of faint galaxies. Possible
magnification, without image splitting of the quasar itself, by some of these
maybe foreground galaxies cannot be excluded. The continuum fuzz (made of the
closest two objects, viz. A and D) is elongated in a direction orthogonal to
the E vector of the optical polarization, as in high-redshift radio-galaxies.
The spectrum of PKS 1610-771 appears strongly curved, in a convex way, with a
maximum of intensity at ~ 7,600 A (2,800 A rest frame), possibly indicating a
strong ultraviolet absorption by dust.

37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics