NOEMA observations support a recoiling black hole in 3C186

Abstract

3C186 is a powerful radio loud quasar (QSO) at the center of a cool-core cluster at z=1.06. Previous studies reported evidence for a projected spatial offset of ~1'' between the isophotal center of the galaxy and the point-source QSO as well as a spectral shift of ~2000 km/s between the narrow and broad line region of the system. In this work we report high-resolution molecular gas CO(4-3) observations of the system taken with NOEMA interferometer. We clearly detect a large reservoir of molecular gas, $M_{H_2}\sim 8\times 10^{10}{M}_{\odot }$, that is cospatial with the host galaxy and likely associated with a rotating disk-like structure. We firmly confirm both the spatial offset of the galaxy's gas reservoir with respect to the continuum emission of the QSO and the spectral offset with respect to the redshift of the broad line region. Our morphological and kinematical analysis confirms that the most likely scenario to explain the 3C186 system is that the QSO is a kicked super-massive black hole (SMBH), which we believe may have resulted from a strong gravitational wave recoil as two SMBHs coalesced after the merger of their host galaxies.

9 pages, Astronomy & Astrophysics Letters in press

References in corpus (11)

• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• 350 Micron Dust Emission from High Redshift Quasars
• Cold molecular gas in the Perseus cluster core - Association with X-ray cavity, Halpha filaments and cooling flow -
• Possibility of Precise Measurement of the Cosmological Power Spectrum With a Dedicated 21cm Survey After Reionization
• Massive binary black holes in galactic nuclei and their path to coalescence
• Cold Molecular Gas in Merger Remnants: I. Formation of Molecular Gas Disks
• Recoiling black holes: electromagnetic signatures, candidates, and astrophysical implications
• Molecular Gas in the Halo Fuels the Growth of a Massive Cluster Galaxy at High Redshift
• Star formation in z>1 3CR host galaxies as seen by Herschel
• SUPER. VI. A giant molecular halo around a z~2 quasar
• New insights on the recoiling/binary black hole candidate J0927+2943 via molecular gas observations

Cited by in corpus (2)

• Star forming and gas rich brightest cluster galaxies at $z\sim 0.4$ in the Kilo-Degree Survey
• Star forming brightest cluster galaxies at $z\sim 0.4$ in KiDS. Further studies of cold gas and stellar properties