Highlight: Quasar feedback revealed by giant molecular outflows (vol. 518)

Vol. 518In section 1. Letters to the Editor24 August 2010

Quasar feedback revealed by giant molecular outflows

by C. Feruglio, R. Maiolino, E. Piconcelli, N. Menci, H. Aussel, A. Lamastra, and F. Fiore, A&A 518, L155 alt

In current theories of galaxy formation, the negative feedback of an AGN is often invoked to stop star formation in massive galaxies. However, direct observational evidence is missing. The present work shows the existence of broad wings in the CO(1-0) spectrum toward Mrk 231, the closest quasar known. The spectrum obtained with the IRAM interferometer reveals velocities of up to 750 km/s on a kpc scale. This corresponds to a giant molecular outflow of about 2000 MSun/year, ten times larger than the ongoing star-formation rate (~200 MSun/year), and able to expel the remaining gas in a dozen million years. The kinetic energy of the outflow is about 7% of the AGN bolometric luminosity, closed to AGN feedback model expectations, while the contributions of star formation and supernovae winds are several orders of magnitude smaller.