Lab Saha, Anshu Chatterjee and Prof. Pratik Majumdar from the Astroparticle Physics and Cosmology Division, SINP and their collaborators have analyzed data for a middle-aged, supernova remnant 3C 391 and improved the statistics. It shows that such supernova remnants are able to accelerate particles to TeV-scale energies. The work has been published in Astrophysical Journal 790 (2014) 65.

Gamma-ray TS map of the 3C 391 neighborhood with a bin size of 0.01 × 0.01 deg. The blue contours show the X-ray data from Suzaku observatory, where 3 contours represent 14, 29, 43 counts. The yellow crosses and circles represent the 2nd Fermi-LAT catalog sources and the black cross and circle is the GeV source from the 2nd Fermi-LAT catalog corresponding to SNR 3C 391. Two red diamonds represent the two masers detected.