SUSY in the sky or a keV signature of sub-GeV gravitino dark matter.

We point out that recently discovered 3.5-keV line in x-ray spectra from various galaxy clusters and the Andromeda galaxy can be naturally explained by physics of a sector responsible for spontaneous supersymmetry breaking in models with R parity. In this scenario, the source of this line could be decay of sgoldstino-scalar superpartner of massive gravitino. At the same time, the dominant dark matter component is stable gravitino whose mass is predicted to be about 0.25 GeV. [ABSTRACT FROM AUTHOR]