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The 2dF QSO Redshift Survey - V. The 10k catalogue

Monthly Notices of the Royal Astronomical Society 322:4 (2001)

Authors:

SM Croom, RJ Smith, BJ Boyle, T Shanks, NS Loaring, L Miller, IJ Lewis

Abstract:

We present a catalogue comprising over 10 000 QSOs covering an effective area of 289.6 deg2, based on spectroscopic observations with the 2-degree Field (2dF) instrument at the Anglo-Australian Telescope. This catalogue forms the first release of the 2dF QSO Redshift Survey. QSO candidates with 18.25 < bJ < 20.85 were obtained from a single homogeneous colour-selected catalogue based on APM measurements of UK Schmidt photographic material. The final catalogue will contain approximately 25 000 QSOs and will be released to the public at the end of 2002, one year after the observational phase is concluded.
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On the origin of the color-magnitude relation in the Virgo Cluster

Astrophysical Journal 551:2 PART 2 (2001)

Authors:

A Vazdekis, H Kuntschner, RL Davies, N Arimoto, O Nakamura, R Peletier

Abstract:

We explore the origin of the color-magnitude relation (CMR) of early-type galaxies in the Virgo Cluster using spectra of very high signal-to-noise ratio for six elliptical galaxies selected along the CMR. The data are analyzed using a new evolutionary stellar population synthesis model to generate galaxy spectra at the resolution given by their velocity dispersions. In particular, we use a new age indicator that is virtually free of the effects of metallicity. We find that the luminosity-weighted mean ages of Virgo ellipticals are greater than ∼8 Gyr and show no clear trend with galaxy luminosity. We also find a positive correlation of metallicity with luminosity, color, and velocity dispersion. We conclude that the CMR is driven primarily by a luminosity-metallicity correlation. However, not all elements increase equally with the total metallicity, and we speculate that the CMR may be driven by both a total metallicity increase and a systematic departure from solar abundance ratios of some elements along the CMR. A full understanding of the role played by the total metallicity, abundance ratios, and age in generating the CMR requires the analysis of spectra of very high quality, such as those reported here, for a larger number of galaxies in Virgo and other clusters.
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The radio galaxy K-z relation to z ~ 4.5

ArXiv astro-ph/0103364 (2001)

Authors:

Matt J Jarvis, Steve Rawlings, Steve Eales, Katherine M Blundell, Chris J Willott

Abstract:

Using a new radio sample, 6C* designed to find radio galaxies at z > 4 along with the complete 3CRR and 6CE sample we extend the radio galaxy K-z relation to z~4.5. The 6C* K-z data significantly improve delineation of the K-z relation for radio galaxies at high redshift (z > 2). Accounting for non-stellar contamination, and for correlations between radio luminosity and estimates of stellar mass, we find little support for previous claims that the underlying scatter in the stellar luminosity of radio galaxies increases significantly at z > 2. This indicates that we are not probing into the formation epoch until at least z > 3.
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First Results from the 2dF QSO redshift survey

ArXiv astro-ph/0103064 (2001)

Authors:

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

Abstract:

We present some initial results from the 2dF QSO redshift survey. The aim of the survey is to produce an optically-selected catalogue of 25000 QSOs over the redshift range 0
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The 2dF QSO Redshift Survey - 10K@2K!

ArXiv astro-ph/0103056 (2001)

Authors:

T Shanks, BJ Boyle, SM Croom, F Hoyle, N Loaring, L Miller, PJ Outram, RJ Smith

Abstract:

With ~10000 QSO redshifts, the 2dF QSO Redshift Survey (2QZ) is already the biggest individual QSO survey. The aim for the survey is to have ~25000 QSO redshifts, providing an order of magnitude increase in QSO clustering statistics. We first describe the observational parameters of the 2dF QSO survey. We then describe several highlights of the survey so far; we present new estimates of the QSO luminosity function and the QSO correlation function. We also present the first estimate of the QSO power spectrum from the 2QZ catalogue, probing the form of the fluctuation power-spectrum out to the \~1000h-1Mpc scales only previously probed by COBE. We find a power spectrum which is steeper than the prediction of standard CDM and more consistent with the prediction of Lambda-CDM. The best-fit value for the power spectrum shape parameter for a range of cosmologies is Gamma=0.1+-0.1. Finally, we discuss how the complete QSO survey will be able to constrain the value of Omega_Lambda by combining results from the evolution of QSO clustering and from a geometric test of clustering isotropy.
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