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Use of neural networks for the identification of new z>=3.6 QSOs from FIRST-SDSS DR5
R. Carballo, J. I. Gonzalez-Serrano, C. R. Benn +1
We aim to obtain a complete sample of redshift > 3.6 radio QSOs from FIRST sources having star-like counterparts in the SDSS DR5 photometric survey (r<=20.2). We found that simple…
Radio spectra and polarisation properties of radio-loud Broad Absorption Line Quasars
F. M. Montenegro-Montes, K. -H. Mack, M. Vigotti +5
We present multi-frequency observations of a sample of 15 radio-emitting Broad Absorption Line Quasars (BAL QSOs), covering a spectral range between 74 MHz and 43 GHz. They display…
A FIRST-APM-SDSS survey for high-redshift radio QSOs
R. Carballo, J. I. Gonzalez-Serrano, F. M. Montenegro-Montes +4
We selected from VLA-FIRST a sample of 94 objects starlike in SDSSS, and with APM colour O-E>2, i.e. consistent with their being high-z QSOs. 78 candidates were classified spectros…
Unusual high-redshift radio BAL quasar 1624+3758
C. R. Benn, R. Carballo, J. Holt +4
We present observations of the most radio-luminous BAL quasar known, 1624+3758, at redshift z = 3.377. The quasar has several unusual properties: (1) The FeII UV191 1787-A emission…
Selection of quasar candidates from combined radio and optical surveys using neural networks
R. Carballo, A. S. Cofino, J. I. Gonzalez-Serrano
The application of supervised artificial neural networks (ANNs) for quasar selection from combined radio and optical surveys with photometric and morphological data is investigated…
A sample of radio-loud QSOs at redshift ~ 4
J. Holt, C. R. Benn, M. Vigotti +5
We obtained spectra of 60 red, starlike objects (E< 18.8) identified with FIRST radio sources, S_{1.4GHz} > 1 mJy. Eight are QSOs with redshift z> 3.6.Combined with our pilot searc…
The European Large Area ISO Survey (ELAIS): The Final Band-merged Catalogue
ELAIS Consortium, :, M. Rowan-Robinson +16
We present the final band-merged ELAIS catalogue at 6.7, 15, 90, and 175 m, and the associated data at u,g,r,i,z,J,H,K, and 20cm. The origin of the survey, infrared and radio ob…
On the origin of the X-ray emission from a narrow-line radioquasar at z>1
X. Barcons, R. Carballo, F. J. Carrera +5
We present new XMM-Newton X-ray observations of the z=1.246 narrow-line radioquasar RX J1011.2+5545 serendipitously discovered by ROSAT. The flat X-ray spectrum previously measured…
Tomography of high-redshift clusters with OSIRIS
A. Fernandez-Soto, J. Bland-Hawthorn, J. I. Gonzalez-Serrano +1
High-redshift clusters of galaxies are amongst the largest cosmic structures. Their properties and evolution are key ingredients to our understanding of cosmology: to study the gro…
Decline of the space density of quasars between z=2 and z=4
M. Vigotti, R. Carballo, C. R. Benn +5
We define a new complete sample of 13 optically-luminous radio quasars M_AB(1450 Angstrom) < -26.9 mag and log P_1.4 GHz(W/Hz) > 25.7 with redshift 3.8 < z < 4.5, obtained by cross…
Observations of the Hubble Deep Field South with the Infrared Space Observatory - II. Associations and star formation rates
R. G. Mann, S. Oliver, R. Carballo +15
We present results from a deep mid-IR survey of the Hubble Deep Field South (HDF-S) region performed at 7 and 15um with the CAM instrument on board ISO. We found reliable optical/n…
Observations of the Hubble Deep Field South with the Infrared Space Observatory - I. Observations, data reduction and mid-infrared source counts
S. Oliver, R. G. Mann, R. Carballo +14
We present results from a deep mid-infrared survey of the Hubble Deep Field South (HDF-S) region performed at 7 and 15 micron with the CAM instrument on board the Infrared Space Ob…
The European Large Area ISO Survey I: Goals, Definition and Observation
Seb Oliver, the ELAIS consortium
We describe the European Large Area ISO Survey (ELAIS). ELAIS was the largest single Open Time project conducted by ISO, mapping an area of 12 square degrees at 15mu with ISO-CAM a…
The shape of the blue/UV continuum of B3-VLA radio quasars: Dependence on redshift, blue/UV luminosity and radio power
R. Carballo, J. I. González-Serrano, C. R. Benn +2
UBVR photometry of a sample of B3-VLA radio quasars, about 80 per cent complete, is used to analyse their spectral energy distribution (SED). The SEDs are generally well fitted wit…
Discovery of an X-ray selected radio-loud obscured AGN at z=1.246
X. Barcons, R. Carballo, M. T. Ceballos +2
We have discovered an obscured active galaxy at redshift z = 1.246 identified with the ROSAT X-ray source RX J1011.2+5545. We report on multiwavelength observations of this source…
K-band imaging of 52 B3-VLA quasars: Nucleus and host properties
R. Carballo, S. F. Sanchez, J. I. Gonzalez-Serrano +2
We present K-band imaging and photometry of a sample of 52 radio loud quasars (RQs) selected from the B3 survey with flux densities above 0.5 Jy at 408 MHz. The optical completenes…
Red quasars not so dusty
C. R. Benn, M. Vigotti, R. Carballo +2
Webster et al (1995) claimed that up to 80% of QSOs may be obscured by dust. They inferred the presence of this dust from the remarkably broad range of B-K optical-infrared colours…
Optical and X-ray properties of the RIXOS AGN: II - Emission lines
E. M. Puchnarewicz, K. O. Mason, F. J. Carrera +9
We present the optical and UV emission line properties of 160 X-ray selected AGN taken from the RIXOS survey (including Halpha, Hbeta, [OIII]5007, MgII2798 and CIII]1909). This sam…
Optical and X-ray properties of the RIXOS AGN: I - The continua
E. M. Puchnarewicz, K. O. Mason, E. Romero-Colmenero +6
We present measurements of the optical and X-ray continua of 108 AGN (Seyfert 1s and quasars) from the Rosat International X-ray/Optical Survey (RIXOS). The sample covers a wide ra…
The Luminosity Function Evolution of Soft X--ray selected AGN in the RIXOS survey
M. J. Page, F. J. Carrera, G. Hasinger +7
A sample of 198 soft X--ray selected active galactic nuclei (AGN) from the ROSAT International X--ray Optical Survey (RIXOS), is used to investigate the X--ray luminosity function…
The proximity effect on the Lyman alpha forest due to a a foreground QSO
A. Fernandez-Soto, X. Barcons, R. Carballo +1
The influence of a foreground QSO on the lyman a forest of another QSO with higher redshift has been investigated by analyzing the spectra of three such objects at redshifts $z=2 -…
The absorption spectra of Q1107+487 and Q1442+295
R. Carballo, X. Barcons, J. K. Webb
We present the first moderate resolution (approx. 40--120 km/s) spectroscopic observations of the bright (V<16.7) high-redshift QSOs Q1107+487 (z_{em} = 2.965) and Q1442+295 (z_{em…
The proximity Effect on the Lyman alpha Forest due to a Foreground QSO
A. Fernandez-Soto, X. Barcons, R. Carballo +1
We present the results of our study on three close pairs of QSOs. Our results are consistent with the existence of a proximity effect due to the foreground QSO, but due to its weak…