Counterpart candidates to the unidentified fermi source 0FGL J1848.6-0138

摘要

Here we report the finding of a few counterpart candidates inside the 95% confidence error box of the Fermi LAT unidentified gamma-ray source 0FGL J1848.6-0138. Among them, the globular cluster GLIMPSE-C01 is specially remarkable. It offers a conceivable physical scenario for gamma-ray production and if confirmed to be counterpart it would be the second globular cluster (after 47 Tuc) associated to a Fermi source. The Fermi-observed spectrum is compared with theoretical predictions in the literature and the association is found to be plausible but not yet certain because of its low Xray to gamma-ray luminosity ratio.