Detection of strong winds driven by a supermassive black hole in La Palma

The supermassive black holes in the center of many galaxies seem to have a major influence on their evolution. This happens during a phase in which the black hole consumes very quickly the material of the galaxy in which it resides and grows at the same time. During this phase, the galaxy has an active galactic nucleus (AGN).

The effect of this activity on the host galaxy is known as the AGN reaction. One of its properties is the galactic winds: it is a gas from the center of the galaxy driven by the energy released by the active nucleus. These winds can reach speeds of up to thousands of kilometers per second, and in the most energetic AGNs, such as quasars, which can clean the centers of galaxies preventing the formation of new stars. It has been shown that the evolution of star formation on cosmological time scales could not be explained without the existence of a regulatory mechanism.

To study these winds in quasars, the Gran Telescopio Canarias (GTC) EMIR infrared spectrograph was used. EMIR was developed at the Instituto de Astrofísica de Canarias and is designed to study the coldest and most distant objects in the universe by analyzing infrared light. Since June 2016, he has settled in one of the thematic centers of the GTC, after a comprehensive testing phase in the workshops of the Instruments Division of the headquarters of the IAC in La Laguna.

The data obtained since then has been used to produce several scientific papers, the last of which is a study of the obscure quasar J1509 + 0434, published today in the journal Monthly Notices of the Royal Astronomical Society Letters and produced by an international team led by Cristina Ramos Almeida, researcher at IAC. This quasar is part of the local universe and is analogous to the more distant and much larger quasars in which the AGN feedback must have a major impact on the formation of new stars.

"EMIR has allowed us to study the winds of the ionized and molecular gases of this quasar using infrared.This analysis is very important because they do not always show similar properties, which tells us a lot about the production of these winds, and how they affect their host galaxies, "says Ramos Almeida. Studying this local and other quasars will allow us to understand what was happening in galaxies when they were young and when they formed their structures, as we see it today.

Based on new EMIR data, the team found that the ionized wind was faster than the molecular wind, reaching speeds of up to 1,200 km / s. However, it is the molecular wind that empties the gas reservoirs of the galaxy (up to 176 solar masses per year). "New observations with ALMA will allow us to confirm this estimate," said José Acosta Pulido, researcher at IAC and co-author of this study.

The next step is to observe a complete sample of near obscured quasars with EMIR in order to study their ionized and molecular winds. We also want to study the stellar populations of their host galaxies. This will allow us to directly confirm the effect of the return of AGN on the evolution of galaxies.