Fermi Large Area Telescope Observation of a Gamma-ray Source at the Position of Eta Carinae

Understand

The Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope detected a gamma-ray source that is spatially consistent with the location of Eta Carinae.

• This source has been persistently bright since the beginning of the LAT survey observations (from 2008 August to 2009 July, the time interval considered here).
• The gamma-ray signal is detected significantly throughout the LAT energy band (i.e., up to ~100 GeV).
• The 0.1-100 GeV energy spectrum is well represented by a combination of a cutoff power-law model (< 10 GeV) and a hard power-law component (> 10 GeV).