2007PASJ...59..727O

begin{HTML}Using Chandra, extended X-ray emission was detected from the direction of 6 globular clusters: 47 Tucanae, NGC 6752, M 5, o Centauri, M 80, and NGC 6266. These X-ray sources, extending to a few arcmin, are located 1'-6' away from the cluster centers, and some are found in the direction of cluster motion through the Galactic halo. All of these sources are concluded to be diffuse, rather than an assembly of faint discrete X-ray sources. Those in 47 Tuc and NGC 6752 have similar spectra, described by a power law with a photon index of ∼2, or a thin-thermal model with a temperature of ∼3-4"keV. Furthermore, they both have 843 MHz radio counterparts. The diffuse emission from α Cen exhibits a ∼1.0keV thermal spectrum, while that from M 5 shows an even softer (∼0.05keV) spectrum. While the diffuse source in o Cen could be a background contaminant, the others are likely to be physically associated with the globular clusters. Then, the absorption-corrected 0.5-4.5 keV luminosity of the sources in 47 Tuc and NGC 6752 becomes (3-6)x10³² erg/s. These results are discussed in the context of shocks produced by the cluster motion through the Galactic halo, and the associated gas heating and particle acceleration.