Group-scale asymmetric abundance structures in the NGC 533 group

By performing a two dimensional spectral analysis on the galaxy group NGC 533 with high-quality Chandra data, we find that the metal abundance distribution in this group is anisotropic. In the area around 2.5' from the center, we find two concentrations of high abundance structures, in which the abundances are significantly higher than their surrounding regions at the 90% confidence level. We find that the total iron mass in these two regions agrees with the iron mass synthesized in the central dominant galaxy in 0.12+0.08−0.03 Gyr. The double-sided configuration of the high abundance structure, together with the point-like radio emission in the center suggests that the abundance structures could have been transported from the center to their present positions by active galactic nucleus (AGN) activity. We further calculate the energy required for transport, and find that it could have been supplied during an AGN period. However, considering that this group is reported to have experienced a recent merger, the possibility that this merger is responsible for the abundance structures still cannot be excluded. (research papers)