The Fermi Bubbles are extended gamma-ray features discovered by the Fermi-LAT gamma-ray telescope. They are elliptical in shape, about 40 by 50 degrees diameter, and symmetric about the Galactic Centre both vertically and horizonally. Their physical size is several kpc. They are probably associated with AGN or starburst activity at the Galactic Centre, and the emission mechanism is most likely inverse-Compton scattering by relativistic electrons. They have also been detected in radio, studied in X-rays with Suzaku, and are probably related to the Galactic Centre chimney seen in X-rays with XMM. The Bubbles contain hot gas which is expected to emit in X-rays, and non-thermal emission is predicted in hard X-rays too. Their large extent on the sky makes the Bubbles an ideal target for the wide-field survey of eRosita. Current Fermi-LAT data allow a precise template to be derived for eRosita studies. Predictions and sensitivity estimates for eRosita will be presented.
In addition, the Galactic interstellar medium emits non-thermally down to X-rays, competing with the source populations and thermal emission which dominate at low energies. Predictions based on the GALPROP model of cosmic-rays and non-thermal processes will be presented.
|Presenter status||eROSITA consortium member|