Searching for the Physical Drivers of Eigenvector 1: From Quasars to Nanoquasars

Abstract

We point out an analogy between two accreting white dwarfs (CH Cyg and MWC 560) with jets and powerful quasars. In spite of the enormous difference in the mass of the central object (a factor ~10⁷), the emission lines are strikingly similar to those of I Zw 1 (the prototype ``narrow-line Seyfert 1'' nucleus whose spectrum is widely used as an Fe II template for almost all quasars). The spectral similarities give us the unique possibility to consider the optical Eigenvector 1 diagram using objects less massive by a factor of millions. Our results reinforce the interpretation of the ``Eigenvector 1 correlations'' found for low-redshift quasars as driven mainly by the source luminosity-to-central compact object mass ratio. The accreting white dwarfs CH Cyg and MWC 560, their jets and emission lines, may well represent the low-energy, nonrelativistic end of the accretion phenomena, which encompass the most powerful quasars and microquasars. The remarkable similarities suggest that they may be legitimately considered ``nanoquasars.''