Fueling the AGN in NGC 6240

8 November 2019

Previous estimates of the mass of supermassive black holes (SMBHs) in mergers of gas rich galaxies suggest that the SMBHs are over-massive, relative to expectations. This may indicate that black holes grow earlier in the merger process than expected, but a small-scale reservoir of gas may also lead to overestimates of the mass. In Medling+, we used high-resolution ALMA observations of the molecular gas in NGC 6240 to measure the mass of molecular gas in the vicinity of the SMBHs. We find that the amount of gas has only a small contribution to the earlier estimates of the SMBH mass. However, these gas reservoirs may indicate that black hole accretion prescriptions assume accretion which is too efficient, on scales of 10 pc. The paper has been published in the Astrophysical Journal Letters and a preprint is available.