Exploring the dark accelerator HESS J1745-303 with Fermi Large Area   Telescope
  We present a detailed analysis of the gamma-ray emission from HESS J1745-303 with the data obtained by the Fermi Gamma-ray Space Telescope in the first ~29 months observation.The source can be clearly detected at the level of ~18-sigma and ~6-sigma in 1-20 GeV and 10-20 GeV respectively. Different from the results obtained by the Compton Gamma-ray Observatory, we do not find any evidence of variability. Most of emission in 10-20 GeV is found to coincide with the region C of HESS J1745-303. A simple power-law is sufficient to describe the GeV spectrum with a photon index of ~2.6. The power-law spectrum inferred in the GeV regime can be connected to that of a particular spatial component of HESS J1745-303 in 1-10 TeV without any spectral break. These properties impose independent constraints for understanding the nature of this "dark particle accelerator". 
C. Y. Hui (1), E. M. H. Wu (2), J. H. K. Wu (2), R. H. H. Huang (3),   K. S. Cheng (2), P. H. T. Tam (3) and A. K. H. Kong (...
astro-ph.HE