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3.2. X-Ray Properties of Clusters
Some of the main properties of the X-ray emission from rich clusters of galaxies are summarized in Table 6.
Property | Typical value of range | Notes |
Lx (2-10 keV) | ~ (1042.5-1045)h-2 erg s-1 | a |
Ix(r) | Ix(r)
![]() ![]() | b |
<![]() | ~ 0.7 | c |
![]() | ![]() ![]() ![]() | |
![]() | d | |
kTx | ~ 2-14 keV | e |
Tx | ~ 2 × 107-108 K | e |
![]() ![]() | ~ 1 | f |
Rc(x) | ~ (0.1-0.3)h-1 Mpc | g |
ne | ~ 3 × 10-3h1/2 cm-3 | h |
![]() ![]() | ~ 1013.5
![]() ![]() ![]() ![]() | i |
![]() ![]() ![]() | ~ 0.07 (range: 0.03-0.15 h-1.5) | i |
Iron abundance | ~ 0.3 solar (range: 0.2-0.5) | j |
a The X-ray luminosity of clusters (2-10 keV band). < Lx > increases with cluster richness and with cluster type (toward compact, elliptical-rich clusters) (Bahcall 1977a, b; Sarazin 1986; Edge et al. 1990; Jones and Forman 1992; David et al. 1993; Burg et al. 1994). | ||
b X-ray surface brightness distribution, Ix(r); Rc is the cluster core radius. | ||
c Mean
< ![]() | ||
d Implied spatial density profile of the hot gas in the cluster [from Ix(r); isothermal]. | ||
e Range of observed X-ray gas temperature in rich clusters (Edge et al. 1990; Henry and Arnaud 1991; Arnaud et al. 1992). | ||
f
![]() ![]() ![]() | ||
g Cluster core radius determined from the X-ray distribution in the cluster (Jones and Forman 1992). | ||
h Typical intracluster gas density in rich cluster cores (Jones and Forman 1992). | ||
i Typical mass (and range of masses) of hot
gas in rich clusters and its fraction of the total (virial) cluster mass
(![]() ![]() ![]() | ||
j Typical iron abundance (and range) of the intracluster gas (in solar units) (Edge and Stewart 1991; Jones and Forman 1992). |