Issue |
A&A
Volume 391, Number 2, August IV 2002
|
|
---|---|---|
Page(s) | 509 - 517 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:20020869 | |
Published online | 02 August 2002 |
Discovery of radio-loud quasars with redshifts above 4 from the PMN sample *,**
1
Department of Physics, University of Oxford, Nuclear & Astrophysics Laboratory, Keble Road, Oxford OX1 3RH, UK e-mail: imh@astro.ox.ac.uk
2
Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK
3
European Southern Observatory, Karl Schwarzschild Straße 2, 85748 Garching b. München, Germany
4
Institute for Astronomy, Royal Observatory, Edinburgh, EH9 3HJ, UK
Corresponding author: I. M. Hook, ihook@gemini.edu
Received:
5
February
2002
Accepted:
11
June
2002
We present results of a new, large survey for high-redshift radio-loud
quasars, which targets quasars with . The survey is based on the
PMN and NVSS radio surveys, optically identified using digitised UKST
B, R and I plates. Six new
flat-spectrum QSOs have been
discovered, and one previously known
QSO rediscovered, based on
their red optical colours. The QSOs discovered in this survey are
bright in both radio and optical bands; in particular PMN J1451-1512
(
,
,
) and PMN J0324-2918 (
,
) are very luminous. PMN J1451-1512 at
is also now
the most distant radio-selected quasar. In addition, 9 new quasars
with
were discovered during the survey. We present spectra
and finding charts for the new quasars. We also derive a surface
density of
for
flat-spectrum
QSOs with
mJy and
mag.
Key words: quasars: general
© ESO, 2002
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