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Galaxy groups in the Two-degree Field Galaxy Redshift Survey: the luminous content of the groups

Eke, V. R. and Frenk, Carlos S. and Baugh, Carlton M. and Cole, Shaun and Norberg, Peder and Peacock, John A. and Baldry, Ivan K. and Bland-Hawthorn, Joss and Bridges, Terry and Cannon, Russell and Colless, Matthew and Collins, Chris and Couch, Warrwick and Dalton, Gavin and De Propris, Roberto and Driver, Simon P. and Efstathiou, George and Ellis, Richard S. and Glazebrook, Karl and Jackson, Carole A. and Lahav, Ofer and Lewis, Ian and Lumsden, Stuart and Maddox, Steve J. and Madgwick, Darren and Peterson, Bruce A. and Sutherland, Will and Taylor, Keith (2004) Galaxy groups in the Two-degree Field Galaxy Redshift Survey: the luminous content of the groups. Monthly Notices of the Royal Astronomical Society, 355 (3). pp. 769-784. ISSN 0035-8711. doi:10.1111/j.1365-2966.2004.08354.x.

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The Two-degree Field Galaxy Redshift Survey (2dFGRS) Percolation-Inferred Galaxy Group (2PIGG) catalogue of ∼29 000 objects is used to study the luminous content of galaxy systems of various sizes. Mock galaxy catalogues constructed from cosmological simulations are used to gauge the accuracy with which intrinsic group properties can be recovered. It is found that a Schechter function is a reasonable fit to the galaxy luminosity functions in groups of different mass in the real data, and that the characteristic luminosity L⋆ is slightly larger for more massive groups. However, the mock data show that the shape of the recovered luminosity function is expected to differ from the true shape, and this must be allowed for when interpreting the data. Luminosity function results are presented in both the bⱼ and rF wavebands. The variation of the halo mass-to-light ratio, ϒ, with group size is studied in both of these wavebands. A robust trend of increasing ϒ with increasing group luminosity is found in the 2PIGG data. Going from groups with bⱼ luminosities equal to 10¹⁰h⁻² L⊙ to those 100 times more luminous, the typical bⱼ-band mass-to-light ratio increases by a factor of 5, whereas the rF-band mass-to-light ratio grows by a factor of 3.5. These trends agree well with the predictions of the simulations which also predict a minimum in the mass-to-light ratio on a scale roughly corresponding to the Local Group. The data indicate that if such a minimum exists, then it must occur at L≲ 10¹⁰h⁻² L⊙, below the range accurately probed by the 2PIGG catalogue. According to the mock data, the bⱼ mass-to-light ratios of the largest groups are expected to be approximately 1.1 times the global value. Assuming that this correction applies to the real data, the mean bⱼ luminosity density of the Universe yields an estimate of Ω_m = 0.26 ± 0.03 (statistical error only). Various possible sources of systematic error are considered, with the conclusion that these could affect the estimate of Ω_m by a few tens of per cent.

Item Type:Article
Related URLs:
URLURL TypeDescription
Baugh, Carlton M.0000-0002-9935-9755
Norberg, Peder0000-0002-5875-0440
Bland-Hawthorn, Joss0000-0001-7516-4016
Colless, Matthew0000-0001-9552-8075
Ellis, Richard S.0000-0001-7782-7071
Additional Information:© 2004 RAS. Accepted 2004 August 23. Received 2004 August 10; in original form 2004 February 13. The 2dF Galaxy Redshift Survey was made possible through the dedicated efforts of the staff of the Anglo-Australian Observatory, both in creating the 2dF instrument and in supporting its use on the telescope. VRE and CMB are Royal Society University Research Fellows. PN is a Zwicky Fellow. JAP and OL are PPARC Senior Research Fellows.
Funding AgencyGrant Number
Royal Society Research FellowshipUNSPECIFIED
Zwicky FellowshipUNSPECIFIED
Particle Physics and Astronomy Research Council (PPARC)UNSPECIFIED
Subject Keywords:galaxies: clusters: general, galaxies: haloes, large-scale structure of Universe
Issue or Number:3
Record Number:CaltechAUTHORS:20200713-181756169
Persistent URL:
Official Citation:V. R. Eke, Carlos S. Frenk, Carlton M. Baugh, Shaun Cole, Peder Norberg, John A. Peacock, Ivan K. Baldry, Joss Bland-Hawthorn, Terry Bridges, Russell Cannon, Matthew Colless, Chris Collins, Warrick Couch, Gavin Dalton, Roberto De Propris, Simon P. Driver, George Efstathiou, Richard S. Ellis, Karl Glazebrook, Carole A. Jackson, Ofer Lahav, Ian Lewis, Stuart Lumsden, Steve J. Maddox, Darren Madgwick, Bruce A. Peterson, Will Sutherland, Keith Taylor, the 2dFGRS Team, Galaxy groups in the Two-degree Field Galaxy Redshift Survey: the luminous content of the groups, Monthly Notices of the Royal Astronomical Society, Volume 355, Issue 3, December 2004, Pages 769–784,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104368
Deposited By: Rebecca Minjarez
Deposited On:20 Jul 2020 21:14
Last Modified:16 Nov 2021 18:31

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