Giodini, S. and Pierini, D. and Finoguenov, A. and Pratt, G. W. and Boehringer, H. and Leauthaud, A. and Guzzo, L. and Aussel, H. and Bolzonella, M. and Capak, P. and Elvis, M. and Hasinger, G. and Ilbert, O. and Kartaltepe, J. S. and Koekemoer, A. M. and Lilly, S. J. and Massey, R. and McCracken, H. J. and Rhodes, J. and Salvato, M. and Sanders, D. B. and Scoville, N. Z. and Sasaki, S. and Smolcic, V. and Taniguchi, Y. and Thompson, D. (2009) Stellar and Total Baryon Mass Fractions in Groups and Clusters Since Redshift 1. Astrophysical Journal, 703 (1). pp. 982-993. ISSN 0004-637X. http://resolver.caltech.edu/CaltechAUTHORS:20091006-134828649
- Published Version
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20091006-134828649
We investigate if the discrepancy between estimates of the total baryon mass fraction obtained from observations of the cosmic microwave background (CMB) and of galaxy groups/clusters persists when a large sample of groups is considered. To this purpose, 91 candidate X-ray groups/poor clusters at redshift 0.1 ≤ z ≤ 1 are selected from the COSMOS 2 deg^2 survey, based only on their X-ray luminosity and extent. This sample is complemented by 27 nearby clusters with a robust, analogous determination of the total and stellar mass inside R_(500). The total sample of 118 groups and clusters with z ≤ 1 spans a range in M_(500) of ~10^(13)-10^(15) M_☉. We find that the stellar mass fraction associated with galaxies at R_(500) decreases with increasing total mass as M^(–0.37 ± 0.04)_(500), independent of redshift. Estimating the total gas mass fraction from a recently derived, high-quality scaling relation, the total baryon mass fraction (f^(stars+gas)_(500) = f^(stars)_(500) + f^(gas)_(500)) is found to increase by ~25%, when M_(500) increases from <M> = 5 × 10^(13) M_☉ to <M> = 7 × 10^(14) M_☉. After consideration of a plausible contribution due to intracluster light (11%-22% of the total stellar mass) and gas depletion through the hierarchical assembly process (10% of the gas mass), the estimated values of the total baryon mass fraction are still lower than the latest CMB measure of the same quantity (WMAP5), at a significance level of 3.3σ for groups of <M> = 5 × 10^(13) M_☉. The discrepancy decreases toward higher total masses, such that it is 1σ at <M> = 7 × 10^(14) M_☉. We discuss this result in terms of nongravitational processes such as feedback and filamentary heating.
|Additional Information:||© 2009 American Astronomical Society. Received 2008 December 16, accepted for publication 2009 July 21. Published 2009 September 3. The authors thank the anonymous referee for her/his valuable comments, which led to a significant improvement of the paper. We acknowledge the contributions of the entire COSMOS collaboration; more information on the COSMOS survey are available at http://www.astr.caltech.edu/∼cosmos. This research was supported by the DFG Cluster of Excellence Origin and Structure of the Universe (http://www.universe-cluster.de). D.P. acknowledges support by the German Deutsches Zentrum für Luft- und Raumfahrt, DLR project number 50 OR 0405.|
|Subject Keywords:||cosmological parameters; cosmology: observations; diffuse radiation; galaxies: clusters: general; galaxies: stellar content; X-rays: galaxies: clusters|
|Official Citation:||Stellar and Total Baryon Mass Fractions in Groups and Clusters Since Redshift 1 S. Giodini, D. Pierini, A. Finoguenov, G. W. Pratt, H. Boehringer, A. Leauthaud, L. Guzzo, H. Aussel, M. Bolzonella, P. Capak, M. Elvis, G. Hasinger, O. Ilbert, J. S. Kartaltepe, A. M. Koekemoer, S. J. Lilly, R. Massey, H. J. McCracken, J. Rhodes, M. Salvato, D. B. Sanders, N. Z. Scoville, S. Sasaki, V. Smolcic, Y. Taniguchi, D. Thompson, and the COSMOS Collaboration 2009 ApJ 703 982-993 doi: 10.1088/0004-637X/703/1/982|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Ruth Sustaita|
|Deposited On:||06 Oct 2009 22:41|
|Last Modified:||21 Sep 2016 22:55|
Repository Staff Only: item control page