GALAXY CLUSTER BARYON FRACTIONS REVISITED

By Anthony H. Gonzalez, Suresh Sivanandam, Ann Zabludoff, Dennis Zaritsky. 2013

193 citations recorded by the source corpus.

We measure the baryons contained in both the stellar and hot-gas components for 12 galaxy clusters and groups at z ∼ 0.1 with M = 1–5 × 1014 M☉. This paper improves upon our previous work through the addition of XMM-Newton X-ray data, enabling measurements of the total mass and masses of each major baryonic component—intracluster medium, intracluster stars, and stars in galaxies—for each system. We recover a mean relation for the stellar mass versus halo mass, , that is 1σ shallower than in our previous result. We confirm that the partitioning of baryons between the stellar and hot-gas components is a strong function of M500; the fractions of total mass in stars and X-ray gas within a sphere of radius r500 scale as and , respectively. We also confirm that the combination of the brightest cluster galaxy and intracluster stars is an increasingly important contributor to the stellar baryon budget in lower halo masses. Studies that fail to fully account for intracluster stars typically underestimate the normalization of the stellar baryon fraction versus M500 relation by ∼25%. Our derived stellar baryon fractions are also higher, and the trend with halo mass weaker, than those derived from recent halo occupation distribution and abundance matching analyses. One difference from our previous work is the weak, but statistically significant, dependence here of the total baryon fraction upon halo mass: . For M500 ≳ 2 × 1014, the total baryon fractions within r500 are on average 18% below the universal value from the seven year Wilkinson Microwave Anisotropy Probe (WMAP) analysis, or 7% below for the cosmological parameters from the Planck analysis. In the latter case, the difference between the universal value and cluster baryon fractions is less than the systematic uncertainties associated with the M500 determinations. The total baryon fractions exhibit significant scatter, particularly at M500 < 2 × 1014 M☉ where they range from 60%–90%, or 65%–100%, of the universal value for WMAP7 and Planck, respectively. The ratio of the stellar-to-gas mass within r500 (M⋆/Mgas), a measure of integrated star-formation efficiency, strongly decreases with increasing M500. This relation is tight, with an implied intrinsic scatter of 12%. The fact that this relation remains tight at low mass implies that the larger scatter in the total baryon fractions at these masses arises from either true scatter in the total baryon content or observational scatter in M500 rather than late-time physical processes such as redistribution of gas to beyond r500. If the scatter in the baryon content at low mass is physical, then our results imply that in this mass range, the integrated star-formation efficiency rather than the baryon fraction that is constant at fixed halo mass.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

View Paper: https://www.semanticscholar.org/paper/5b5b9c6c150c89bf259191d0538484ab72e81b6a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Electrical and Electronic Engineering

In Instrumentation

Citations in the corpus

Towards a realistic population of simulated galaxy groups and clusters (2013, methodology): “As discussed in detail in Budzynski et al. (2014), there is a difference in the slope of the trend of the stellar mass/light with halo mass that they measure and that measured by Gonzalez et al. (2007) (and now Gonzalez et al. 2013).”
The EAGLE simulations of galaxy formation: the importance of the hydrodynamics scheme (2015, methodology): “For comparison, we show observational data taken from Sanderson et al. (2013), Gonzalez et al. (2013) and Kravtsov et al. (2014) as well as the SDSS image stacking result of Budzynski et al. (2014).”
The BAHAMAS project: Calibrated hydrodynamical simulations for large-scale structure cosmology (2016, background): “Common to the Gonzalez et al. (2013), Kravtsov, Vikhlinin, & Meshscheryakov (2014), and Budzynski et al. (2014) studies is the inclusion of intracluster light (ICL) and the use of X-ray observations (assuming hydrostatic equilibrium) to derive the halo mass.”
DETECTION OF AN UNIDENTIFIED EMISSION LINE IN THE STACKED X-RAY SPECTRUM OF GALAXY CLUSTERS (2014, methodology): “Stellar masses of each cluster were determined using the stellar mass − total mass scaling relation (Gonzalez et al. 2013).”
Theoretical Challenges in Galaxy Formation (2016, background): “As a significant fraction of mass can be accreted in mergers with smaller and less bound systems (Gabor & Davé 2012, Lackner et al. 2012), this stellar mass is added to the systems at large radii (Navarro-González et al. 2013, Oser et al. 2010, Qu et al. 2017, Rodriguez-Gomez et al. 2016).”
A new method to quantify the effects of baryons on the matter power spectrum (2015, background): “In principle observations of X-ray radiation and the SZ effect can be used to measure gas profiles in clusters and groups.”
First results from the IllustrisTNG simulations: the stellar mass content of groups and clusters of galaxies (2017, methodology): “In the bottom panel of Figure 10 grey data points represent the findings of Kravtsov et al. (2014) MNRAS 000, 000–000 (0000) and Gonzalez et al. (2013) for what they call their BCG fraction to the total mass, with the former being measured by a triple-Sersic fit to the central’s profile…”
Baryon impact on the halo mass function: Fitting formulae and implications for cluster cosmology (2015, background): “Also shown are observational results at low redshift (Laganá et al. 2011; Gonzalez et al. 2013), where we update the total and stellar masses for a subset of clusters as presented in Kravtsov, Vikhlinin & Meshscheryakov (2014), and at high redshift 〈z〉 = 0.9 (Chiu et al. 2016).”
Introducing the Illustris Project: the evolution of galaxy populations across cosmic time (2014, methodology): “…probed by direct observations of individual systems, using techniques such as weak lensing (Mandelbaum et al. 2006), cluster atmosphere modelling (Gonzalez et al. 2013) or satellite kinematics (Conroy et al. 2007), and it can also be inferred with indirect methods employing large galaxy…”
Stellar Mass—Halo Mass Relation and Star Formation Efficiency in High-Mass Halos (2014, methodology): “…the intra-cluster light (ICL) and are estimated to contain significant fraction of the BCG mass (Gonzalez et al. 2005) and up to ∼ 20 − 40% of the total stellar mass within the virial radius (Zibetti et al. 2005; Gonzalez et al. 2007; Skibba et al. 2007; Gonzalez et al. 2013; McGee & Balogh 2010).”