Detection of the Entropy of the Intergalactic Medium: Accretion Shocks in Clusters, Adiabatic Cores in Groups

Details Detection of the Entropy of the Intergalactic Medium: Accretion Shocks in Clusters, Adiabatic Cores in Groups Detection of the Entropy of the Intergalactic Medium: Accretion Shocks in Clusters, Adiabatic Cores in Groups

1999-07-21

arxiv.org/abs/astro-ph/9907299v2

Astrophys.J. 542 (2000) 106-119

Astronomy and Astrophysics

Astrophysics

ApJ accepted, 31 pages including 8 figures. Important material added; references updated

Scientific paper

10.1086/309500

The thermodynamics of the diffuse, X-ray emitting gas in clusters of galaxies is linked to the entropy level of the intra cluster medium. In particular, models that successfully reproduce the properties of local X-ray clusters and groups require the presence of a minimum value for the entropy in the center of X-ray halos. Such a minimum entropy is most likely generated by non-gravitational processes, in order to produce the observed break in self-similarity of the scaling relations of X-ray halos. At present there is no consensus on the level, the source or the time evolution of this excess entropy. In this paper we describe a strategy to investigate the physics of the heating processes acting in groups and clusters. We show that the best way to extract information from the local data is the observation of the entropy profile at large radii in nearby X-ray halos (z~0.1), both at the upper and lower extremes of the cluster mass scale. The spatially and spectrally resolved observation of such X-ray halos provides information on the mechanism of the heating. We demonstrate how measurements of the size of constant entropy (adiabatic) cores in clusters and groups can directly constrain heating models, and the minimum entropy value. We also consider two specific experiments: the detection of the shock fronts expected at the virial boundary of rich clusters, and the detection of the isentropic, low surface-brightness emission extending to radii larger than the virial ones in low mass clusters and groups. Such observations will be a crucial probe of both the physics of clusters and the relationship of non-gravitational processes to the thermodynamics of the intergalactic medium.

Affiliated with

Also associated with

No associations

Rating

Detection of the Entropy of the Intergalactic Medium: Accretion Shocks in Clusters, Adiabatic Cores in Groups does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Detection of the Entropy of the Intergalactic Medium: Accretion Shocks in Clusters, Adiabatic Cores in Groups, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of the Entropy of the Intergalactic Medium: Accretion Shocks in Clusters, Adiabatic Cores in Groups will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-286030