Physical Implications of the X-ray Properties of Galaxy Groups and Clusters

By Arif Babul, M. Balogh, Geraint F. Lewis, Gregory B. Poole. 2001

138 citations recorded by the source corpus.

Within the standard framework of structure formation, where clusters and groups of galaxies are built up from the merging of smaller systems, the physical properties of the intracluster medium, such as the gas temperature and the total X-ray luminosity, are predicted to possess well defined self-similar scaling relations. Observed clusters and groups, however, show strong deviations from these predicted relations. We argue that these deviations are unlikely to be entirely due to observational biasses; we assume they are physically based, due to the presence of excess entropy in the intracluster medium in addition to that generated by accretion shocks during the formation of the cluster. Several mechanisms have been suggested as a means of generating this entropy. Focussing on those mechanisms that preheat the gas before it becomes a constituent of the virialized cluster environment, we present a simple, intuitive, physically motivated, analytic model that successfully captures the important physics associated with the accretion of high entropy gas onto group and cluster-scale systems. We use the model to derive the new relationships between the observable properties of clusters and groups of galaxies, as well as the evolution of these relations. These include the luminosity-temperature and luminosity-� relations, as well as the temperature distribution function and X-ray luminosity function. These properties are found to be a more accurate description of the observations than those predicted from the standard framework. Future observations that will further test the efficacy of the preheated gas scenario are also discussed.

Subfields: Astronomy and Astrophysics, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/7338e9457c1d7cb36e4673c7472502b69204f452

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 Global and Planetary Change

Citations in the corpus

X‐ray properties of galaxy clusters and groups from a cosmological hydrodynamical simulation (2003, background): “…of the ICM (e.g., Evrard & Henry 1991; Kaiser 1991; Bower 1997; Cavaliere, Menci & Tozzi 1998; Balogh, Babul & Patton 1999; Tozzi & Norman 2001; Babul et al. 2002), and those which resort on the ef- fects of radiative cooling (e.g., Bryan 2000; Voit & Bryan 2001; Wu & Xue 2002; Voit et al.…”
Jet-regulated cooling catastrophe (2010, background): “Pre-heating of the gas destined to fall into a cluster potential well during proto-galactic stages has also been proposed as a means to empty gas on galactic scales in these massive haloes (Babul et al. 2002).”
Hydrodynamical simulations of cluster formation with central AGN heating (2005, background): “…invoked some sort of nongravitational heating to explain the cluster scaling relations (e.g. Kaiser 1991; Navarro, Frenk & White 1995; Bower 1997; Tozzi & Norman 2001; Voit & Bryan 2001; Borgani et al. 2001, 2004; Babul et al. 2002; Voit et al. 2002, 2003; Oh & Benson 2003; Tornatore et al. 2003).”
Quasar Feedback: The Missing Link in Structure Formation (2004, background): “…that they are able to generate the 1 keV of energy per gas particle required to account for cluster preheating (Cavaliere et al. 1998; Balogh et al. 1999; Kravtsov & Yepes 2000; Wu et al. 2000; Bialek et al. 2001; Borgani et al. 2001; Brighenti & Mathews 2001; Tozzi et al. 2000; Babul et al. 2002).”
The Formation of a Realistic Disk Galaxy in Λ-dominated Cosmologies (2002, background): “Numerical and semi-analytical results (e.g Borgani et al. 2002, Babul et al. 2002) show that significant energy injection leading to an entropy floor of 50–100 keV/cm2, is needed on the mass scale of small groups (just a factor of ten higher than the mass of the galaxy in our study) to reduce the…”
Modified Entropy Models for the Intracluster Medium (2002, background): “…symmetric accretion of preheated gas (e.g., Cavaliere, Menci & Tozzi 1999; Tozzi & Norman 2001), and semianalytic models that consider the merger and star formation history of clusters (e.g., Wu, Fabian, & Nulsen 1998, 2000; Balogh, Babul, & Patton 1999; Bower et al. 2001; Babul et al. 2002).”
Formation of Galaxy Clusters (2012, methodology): “3 UNDERSTANDING THE FORMATION OF GALAXY CLUSTERS Both analytical models (e.g. Babul et al. 2002, Tozzi & Norman 2001, Voit et al. 2003) and hydrodynamical simulations (e.g. Bialek, Evrard & Mohr2001; Borgani et al. 2002; Muanwong et al. 2002) have demonstrated that with a suitablepre-heating…”
Scaling laws in X-ray galaxy clusters at redshift between 0.4 and 1.3 (2003, background): “…are currently interpreted as evidence for non-gravitational processes, such as extra heating and radiative cooling, that affect the assembly of the baryons in the cluster potential well (e.g. Cavaliere et al. 1999; Bower et al. 2001; Tozzi & Norman 2001; Babul et al. 2002; Voit et al. 2002).”
The Birmingham-CfA cluster scaling project - III. Entropy and similarity in galaxy systems (2003, methodology): “Firstly, the effect we invoke is intimately linked to the fact that the accreting gas is largely confined to filaments, and hence will not be seen in analytical and semi-analytical models, such as those of Tozzi & Norman (2001) and Babul et al. (2002), which assume spherically symmetric accretion.”
Fossil H ii regions: self-limiting star formation at high redshift (2003, methodology): “The models we construct are in the spirit of Voit et al (2002); Tozzi & Norman (2001); Oh & Benson (2003); Babul et al (2002), which match observations of low-redshift cluster X-ray profiles well.”
On the Origin of Intracluster Entropy (2003, unknown): “Other models require 200–400 keV cm2 [ ð2:0 4:0Þ 1033 ergs cm3 g 5/3; e.g., Balogh et al. 1999; Tozzi & Norman 2001; Babul et al. 2002].”
The nature and space density of fossil groups of galaxies (2003, methodology): “3 using the relatively simple analytic model of Babul et al. (2002) to predict the LX–”
Heating Hot Atmospheres with Active Galactic Nuclei (2007, background): “The gas temperature of a hot atmosphere is most sensitive to the gravitating mass profile and, to a lesser degree, the history of heating by gravitational and nongravitational processes (Voit 2005; Babul et al. 2002).”
The impact of mergers on relaxed X-ray clusters – I. Dynamical evolution and emergent transient structures (2006, methodology): “We follow the analytic prescription of Babul et al. (2002) and McCarthy et al. (2004) to produce systems which conform with recent theoretical and observational insights into cluster structure.”
The GEMS project: X-ray analysis and statistical properties of the group sample (2004, result): “The idea of a universal “entropy floor” (Ponman et al. 1999), which could have led to an isentropic IGM in the poorest systems (Babul et al. 2002), and hence to an LXTX slope of ∼ 5, has now been shown to be incorrect in two ways.”
Gas expulsion by quasar-driven winds as a solution to the overcooling problem in galaxy groups and clusters (2010, background): “And both groups and clusters have excess entropy relative to theoretical models that only account for gravitational heating (e.g. Balogh, Babul & Patton 1999; Babul et al. 2002; Voit et al. 2002).”
The mass profile of A1413 observed with XMM-Newton: Implications for the M-T relation (2002, background): “We simply note that pure pre-heating seems to have a small effect of the M−T relation in the high temperature range of A1413 (Loewenstein 2000; Tozzi & Norman 2001; Babul et al. 2002) and that models including cooling (e.g. Thomas et al. 2002) seem to be more successful.”