Broad HI absorption in the candidate binary black-hole 4C37.11 (B2 0402+379)

Abstract

We report the discovery of extremely broad 21-cm HI absorption (FWZI ~1600 km/s) detected with the Westerbork Synthesis Radio Telescope in the radio source 4C37.11 (B2 0402+379). This object has been claimed to host a super-massive binary black hole (Rodriguez et al. 2006). The main features in the absorption profile are two components, separated by ~1100 km/s. The HI absorption in 4C37.11 is unusual because it is the first case where such broad absorption is found to be centred on the systemic velocity of the host galaxy and not asymmetric and blueshifted as is seen in all other galaxies with broad HI absorption. Given the large width of the absorption, we suggest that a possible explanation for the extreme properties of the HI absorption is that it is the kinematic signature of a binary black hole. If this interpretation is correct, the combined black hole mass derived from the absorption profile is consistent with that derived from the luminosity of the spheroid. If the broad absorption is indeed due to a binary black hole, this finding confirms the importance of the gaseous component in the merging process of supermassive black holes.

Accepted for publication in A&A Letter, 4 pages, 2 figures

References in corpus (11)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Relation between Black Hole Mass, Bulge Mass, and Near-Infrared Luminosity
• Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research
• Discovery of a binary AGN in the ultraluminous infrared galaxy NGC 6240 using Chandra
• A Compact Supermassive Binary Black Hole System
• Rapid Formation of Supermassive Black Hole Binaries in Galaxy Mergers with Gas
• Fast neutral outflows in powerful radio galaxies: a major source of feedback in massive galaxies
• Fast outflows in compact radio sources: evidence for AGN-induced feedback in the early stages of radio source evolution
• Observations of HI Absorbing Gas in Compact Radio Sources at Cosmological Redshifts
• HI absorption in radio galaxies: effect of orientation or interstellar medium?
• Breaking All the Rules: The Compact Symmetric Object 0402+379

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