* Astronomy

Title: B2 0954+25A: a typical Fermi blazar or a gamma-loud Narrow Line Seyfert 1
Authors: G. Calderone, G. Ghisellini, M. Colpi, M. Dotti

B2 0954+25A, detected by the Fermi satellite, is a blazar with interesting observational properties: it has been observed to transit from a jet dominated to a disk dominated state; its radio spectrum appears flat at all observing frequencies (down to 74 MHz); optically, the H \beta line profile is asymmetric. The flatness of radio spectrum suggests that the isotropic emission from radio lobes is very weak, despite the large size of its jet (\gtrsim 500 kpc). Its broad--band spectral energy distribution is surprisingly similar to that of the prototypical gamma--ray, radio loud, Narrow Line Seyfert 1 (\gamma--NLS1) galaxy PMN J0948+0022. In this work we revisit the mass estimates of B2 0954+25A considering only the symmetric component of the H \beta line and find (1--3) x 10^8 solar masses. In light of our composite analysis, we propose to classify the source as a transition object between the class of Flat Spectrum Radio Quasar and gamma-ray, radio loud NLS1. A comparison with two members of each class (3C 273 and PMN J0948+0022) is discussed.

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