J073422.2+265143.9
Link
to XCS-DR1 entry
 |  |
| Fig. 1: The SDSS optical image with the XCS X-ray contours overlaid. | Fig. 2: The colour-magnitude diagram used to determine the magnitude gap. Green triangles are spectroscopic cluster members and circles are photometric cluster members. Red triangles are spectroscopic non-members. Only cluster members within ±0.2 mag of the r-i colour of the fossil galaxy (dotted lines) are used to calculate the gap. The two diamonds denote the second and the fourth brightest galaxy. |
Notes
This z=0.0796 system is located at
07:34:22.2 +26:51:43.9. The CMD shows an RS and all spectroscopic
members lay on it. The magnitude gap is 3.0 based on SDSS
spectroscopic data, i.e. all of the four brightest galaxies have a
spectroscopic redshift. The X-ray emission has TX=1.1 keV
and the peak lies ~1.5 kpc from the FG. The system is located
near the edge of the SDSS footprint but at a distance of
~10.0R200 both Δm14 and
Ltot are unaffected. The X-ray source is extended with
R200=0.67 Mpc or ~30R90. Reducing
R200 by its error would increase the magnitude gap by
0.5. The system has a velocity dispersion of 411 km s-1
based on 18 galaxies. This system was classified as a fossil in
Díaz-Gímenez et al. (2008) and was an XMM target
in a program to study fossil systems. Díaz-Gímenez et
al. (2008) quote a virial radius of 1.6 Mpc (twice as large as that
found here) and a velocity dispersion of 551 km s-1.
Fossil System
| XCS ID | Δm14 | R200 | LX | TX | Ltot | ΣL24 |
|---|
| XMMXCS J073422.2+265143.9 | 3.0 | 0.67 | 0.21 | 1.1 | 2.86 | 0.41 |
Fossil Galaxy
| SDSS ID | z | M∗ | Age | Z | log(SSFR) | Lgal |
|---|
| J073422.21+265144.9 | 0.0796 | 0.82 | 8.1 | 0.032 | -12.37 | 1.88 |