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arXiv · 1007.3738

The peculiar optical spectrum of 4C+22.25: Imprint of a massive black hole binary?

Roberto Decarli·Massimo Dotti·Carmen Montuori·Tiina Liimets·Alessandro Ederoclite
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Abstract

We report the discovery of peculiar features in the optical spectrum of 4C+22.25, a flat spectrum radio quasar at z=0.4183 observed in the SDSS and in a dedicated spectroscopic follow-up from the Nordic Optical Telescope. The Hbeta and Halpha lines show broad profiles (FWHM~12,000 km/s), faint fluxes and extreme offsets (Delta v=8,700+/-1,300 km/s) with respect to the narrow emission lines. These features show no significant variation in a time lag of ~3.1 yr (rest frame). We rule out possible interpretations based on the superposition of two sources or on recoiling black holes, and we discuss the virtues and limitations of a massive black hole binary scenario.

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Roberto Decarli, Massimo Dotti, Carmen Montuori, Tiina Liimets, Alessandro Ederoclite. 2010-07-21. The peculiar optical spectrum of 4C+22.25: Imprint of a massive black hole binary?. https://doi.org/10.1088/2041-8205%2F720%2F1%2Fl93

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