Metal-rich multi-phase gas in M 87 -: AGN-driven metal transport, magnetic-field supported multi-temperature gas, and constraints on non-thermal emission observed with XMM-Newton

We use deep (similar to 120 ks) XMM-Newton data of the M 87 halo to analyze its spatially resolved temperature structure and chemical composition. We focus particularly on the regions of enhanced X-ray brightness associated with the inner radio lobes, which are known not to be described very well by single-temperature spectral models. Compared to a simple two-temperature fit, we obtain a better and more physical description of the spectra using a model that involves a continuous range of temperatures in each spatial bin. The range of temperatures of the multiphase gas spans similar to 0.6-3.2 keV. Such a multiphase structure is only possible if thermal conduction is suppressed by magnetic fields. In the multi-temperature regions, we find a correlation between the amount of cool gas (with a temperature below that of the surrounding X-ray plasma) and the metallicity, and conclude that the cool gas is more metal-rich than the ambient halo. In the frame of the assumed thermal model, we estimate the average Fe abundance of the cool gas to similar to 2.2 solar. Our results thus point toward the key role of the active galactic nucleus (AGN) in transporting heavy elements into the intracluster medium through the uplift of cool, metal-rich gas from the galaxy. However, the abundance ratios of O/Si/S/Fe in and outside the X-ray arms are similar, indicating that the dominant fraction of metals in the gas halo was uplifted by AGN outbursts relatively recently compared to the age of M 87. Our best estimate for the mass of the cool gas is 5 x 10(8) M-circle dot, which probably stems from a mixture of ICM, stellar mass loss, and Type Ia supernova products. approximate to 30-110 Myr are required to produce the observed metals in the cool gas. Finally, we put upper limits on possible non-thermal X-ray emission from M 87 and, combining it with the 90 cm radio maps, we put lower limits of around similar to 0.5-1.0 mu G on the magnetic field strength.