SiO maser sources toward globular clusters

We report on the detection of SiO masers in Asymptotic Giant Branch variables toward bulge/disk globular clusters. In five out of six cases, the radial velocities are compatible with the optically measured radial velocities of globular clusters in the assessed uncertainty. Two sources, toward Terzan 5 and Terzan 12, lie very close to the cluster centers. The objects toward Pal 6 and Terzan 12 have luminosities appropriate to the AGB tip in globular clusters, while those toward NGC 6171, Pal 10, and Terzan 5 are brighter than expected. It is suggested that the latter three may have evolved from merged binaries, offering a test for binary-evolution scenarios in globular clusters, if the membership is approved.