Table 7. Correlations Between X-Ray and
Optical Properties. a
|
Properties
| Correlation
|
|
r-T
| r (km
s-1) (332
± 52)[kT (kev)]0.6 ± 0.1
|
T-N0.5
| kT (keV)
0.3N0.50.95 ± 0.18
|
Lx-N0.5
| Lx(bol) ~ 1.4 ×
1040N0.53.16 ±
0.15h-2
|
Lx-fsp
| Lx(bol)
0.6 ×
1043fsp-2.16 ±
0.11h-2
|
fsp-T
| fsp
1.2[kT
(kev)]-0.94 ± 0.38
|
T-Lx
| kT (keV)
0.3[Lx(bol)
h2/1040]0.297 ± 0.004
|
|
a
r is the
galaxy line-of-sight velocity dispersion
in the cluster (km s-1).
T is the temperature of the intracluster gas [kT(keV)].
N0.5 is the central galaxy density in the cluster [number
of galaxies brighter than m3 + 2m, within
r
0.5h50-1
= 0.25 h-1 of the cluster center
(Bahcall 1977a;
Edge and Stewart 1991)].
Lx(bol) is the bolometric X-ray luminosity of the cluster
(erg s-1).
fsp is the fraction of spiral galaxies in the cluster
(
1.5h-1 Mpc)
(Bahcall 1977b;
Edge and Stewart 1991).
Typical uncertainties of the coefficients are ~ 50% (see references).
|