Open AccessAre we missing baryons in galaxy clusters?
Author(s) -
Ettori S.
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06810.x
Subject(s) - physics , baryon , astrophysics , galaxy cluster , cmb cold spot , intracluster medium , galaxy , cluster (spacecraft) , astronomy , galaxy groups and clusters , stars , cosmic microwave background , anisotropy , quantum mechanics , computer science , programming language
The recent constraints on cosmological parameters obtained from the observations of the WMAP satellite limit the cosmic baryon fraction in a range that is larger than, and marginally consistent with, what is measured in galaxy clusters. This raises the question of whether or not we are considering all the ingredients of the cluster baryonic budget. Carefully weighing the baryons in X‐ray‐emitting plasma and stars in cluster galaxies, I conclude that the cluster baryonic pie consists of 13 (with a 1σ range of 8–19) per cent of stars, 70 (56–89) per cent of intracluster hot medium and 17 (0–33) per cent (and a probability of 73 per cent of being larger than 0) of ‘other’ baryons, presumably in the form of warm (10 5 –10 7 K) material.