Are extended nebulae around quasars ordinary galaxies

An attempt is made to reveal the nature of extended nebulae detected in recent years around all nearby (z<0.5) quasi-stellar objects (QSO). Basic data are briefly described that may help to estimate, for all of these nebulae, the dependences between their luminosities (L), velocity dispersions (σ) and dimensions (2R). Similar dependences for normal galaxies are then discussed and used as a basis for comparison of the nebulae enveloping QSO with normal galaxies. Although the available observation data on the nebulae are not sufficient to make final conclusion, it seems, however, that the dependences L approximately σ4 and L approximately Rν , whicn are typical of gravitatxonaily bound normal stellar systems, are not valid for quasi-galactic systems around the QSO