Euclid

Research group

Research theme

Sub department

About

Related research groups

Possible arcminute-separation gravitational lensed QSOs in the 2dF QSO survey

ArXiv astro-ph/0210644 (2002)

Authors:

L Miller, AM Lopes, RJ Smith, SM Croom, BJ Boyle, T Shanks, P Outram

Abstract:

We report the possible discovery of multiple gravitationally-lensed images of QSOs with angular separations on arcminute scales. The QSOs were selected from the completed 2dF QSO survey as having redshifts and optical colours which are statistically consistent. In this paper we present higher-quality optical spectra of the candidates and discuss the likelihood of their genuinely being systems lensed by massive clusters of galaxies. From a comparison of the spectra it appears that up to six pairs of QSOs may be lensed multiple images, although the true number may be less than that and further observations should be undertaken to amass more evidence and to detect the lensing clusters. Two of the candidates may be associated with low redshift clusters of galaxies.
Details from ArXiV
More details from the publisher
More details

White dwarfs in the 2dF QSO redshift survey - I. Hydrogen-rich (DA) stars

Monthly Notices of the Royal Astronomical Society 335:3 (2002) 673-686

Authors:

S Vennes, RJ Smith, BJ Boyle, SM Croom, A Kawka, T Shanks, L Miller, N Loaring

Abstract:

We report the spectroscopic identification of close to 1000 hydrogen-rich (DA) white dwarfs discovered in the course of the Anglo-Australian 2dF QSO Redshift Survey (2QZ). We measured the atmospheric parameters of a subsample of 201 stars based on good-quality Balmer line spectra and we determine the 2QZ population characteristics. Over ten per cent of the sample are potential ZZ Ceti variables. We estimate the DA white dwarf birthrate (bDA = 0.5-1.0 × 10-12 yr-1 pc-3) and the scaleheight (h = 220-300 pc) of the population in the thin disc of the Galaxy by combining information acquired in the Palomar-Green, AAT-UVX and new 2QZ surveys. White dwarfs appear related to G and late-F progenitors. A catalogue of 201 DA white dwarfs is presented.
More details from the publisher
More details

The correlation of line strength with luminosity and redshift from composite QSO spectra

ArXiv astro-ph/0207571 (2002)

Authors:

SM Croom, K Rhook, EA Corbett, BJ Boyle, H Netzer, NS Loaring, L Miller, PJ Outram, T Shanks, RJ Smith

Abstract:

We have generated a series of composite QSO spectra using over 22000 individual low resolution (~8A) QSO spectra obtained from the 2dF (18.25
Details from ArXiV
More details from the publisher
More details

Erratum: “Discovery of Radio-Loud Broad Absorption Line Quasars Using Ultraviolet Excess and Deep Radio Selection” (ApJ, 505, L7 [1998])

The Astrophysical Journal American Astronomical Society 571:2 (2002) l191-l191

Authors:

MS Brotherton, W van Breugel, RJ Smith, BJ Boyle, T Shanks, SM Croom, L Miller, RH Becker
More details from the publisher

Clustering in the 2dF QSO Redshift Survey

ArXiv astro-ph/0205039 (2002)

Authors:

SM Croom, BJ Boyle, NS Loaring, L Miller, P Outram, T Shanks, RJ Smith, F Hoyle

Abstract:

We present clustering results from the 2dF QSO Redshift Survey (2QZ) which currently contains over 20,000 QSOs at z<3. The two-point correlation function of QSOs averaged over the entire survey (~1.5) is found to be similar to that of local galaxies. When sub-dividing the sample as a function of redshift, we find that for an Einstein-de Sitter universe QSO clustering is constant (in comoving coordinates) over the entire redshift range probed by the 2QZ, while in a universe with Omega_0=0.3 and Lambda_0=0.7 there is a marginal increase in clustering with redshift. Sub-dividing the 2QZ on the basis of apparent magnitude we find only a slight difference between the clustering of QSOs of different apparent brightness, with the brightest QSOs having marginally stronger clustering. We have made a first measurement of the redshift space distortion of QSO clustering, with the goal of determining the value of cosmological parameters (in partcular Lambda_0) from geometric distortions. The current data do not allow us to discriminate between models, however, in combination with constraints from the evolution of mass clustering we find Omega_0=1-Lambda_0=0.23 +0.44-0.13 and beta(z~1.4)=0.39 +0.18-0.17. The full 2QZ data set will provide further cosmological constraints.
Details from ArXiV
More details from the publisher