J124425.9+164758.0
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=0.2346 system is located at
12:44:25.9 +16:47:58.0. The FG in this system has a double core,
therefore we cannot trust the sky-subtraction correction and so have
not applied it. This means that the magnitude gap of 2.3 is a lower
limit. If we applied the estimated correction the gap would be 3.3 and
if we only applied the average correction from the other 16 FSs the
gap would be 2.6, therefore we accept this as an FS. The X-ray
temperature of the system is TX=1.3 keV and the X-ray
emission peak lies ~25.8 kpc from the FG. The X-ray source is
extended with R200=0.63 Mpc or ~20R90. No
velocity dispersion could be measured for this system.
Fossil System
| XCS ID | Δm14 | R200 | LX | TX | Ltot | ΣL24 |
|---|
| XMMXCS J124425.9+164758.0 | 2.3 | 0.63 | 0.06 | 1.3 | 5.85 | 0.91 |
Fossil Galaxy
| SDSS ID | z | M∗ | Age | Z | log(SSFR) | Lgal |
|---|
| J124425.43+164756.9 | 0.2346 | 0.52 | 11.8 | 0.027 | -12.29 | 3.64 |