Study Suggests Black Holes can Control Galaxy Formation

Image of the quasar host galaxy from the UC San Diego research team’s data. The distance to this quasar galaxy is ~9.3 billion light years. The four-color image shows findings from use of the Keck Observatory and ALMA. As seen from Keck Observatory, the green colors highlight the energetic gas across the galaxy that is being illuminated by the quasar. The blue color represents powerful winds blowing throughout the galaxy. The red-orange colors represent the cold molecular gas in the system as seen from ALMA. The supermassive black hole sits at the center of the bright red-orange circular area slightly below the middle of the image. CREDIT: A. Vayner and research team.

The latest astronomical findings supported by W.M. Keck Observatory on Maunakea are shedding light on how supermassive black holes at the center of a galaxy impacts neighboring star formation. Until now, astronomers did not fully understand how this phenomena occurred.

“Supermassive black holes are captivating,” said Shelley Wright, a University of California San Diego professor of physics who led the study published in The Astrophysical Journal. “Understanding why and how galaxies are affected by their supermassive black holes is an outstanding puzzle in their formation.”

Wright, graduate student Andrey Vayner, and their colleagues researched the wind forces generated by a bright, supermassive black hole known as a “quasar” at the center of host galaxy 3C 298. The team found that these powerful winds spread throughout the entire galaxy and influence the growth of stars.

“This is remarkable that the supermassive black hole is able to impact stars forming at such large distances,” said Wright.

Galaxies in the galactic neighborhood of 3C 298 are observed to have a mass that is tightly correlated with the mass of the accompanying supermassive black hole. Wright’s and Vayner’s research indicates that 3C 298 itself does not share this correlation. Their study shows it to be 100 times less massive than it should be given the monstrous proportion and density of its supermassive black hole.

The finding indicates that this particular supermassive black hole was established well before the galaxy itself—and that energetic winds generated by the quasar are capable of controlling the growth of the galaxy.

“The most enjoyable part of researching this galaxy has been putting together all the data from different wavelengths and techniques,” said Vayner. “Each new dataset that we obtained on this galaxy answered one question and helped us put some of the pieces of the puzzle together. However, at the same time, it created new questions about the nature of galaxy and supermassive black hole formation.”

The UC San Diego study was conducted using multiple astronomical facilities including Keck Observatory’s instrument OSIRIS (OH-Suppressing Infrared Imaging Spectrograph) and its advanced adaptive optics (AO) system. The AO system allows ground-based telescopes to capture images as clear as those obtained from space by compensating for Earth’s atmospheric interference on incoming light.

Researchers also utilized the Atacama Large Millimeter/submillimeter Array (ALMA), an international observatory located in Chile that detects millimeter wavelengths and produces high-resolution images.

The study is the first of a series on distant quasars and their energetic impact on star formation and galaxy growth. Vayner and the team will continue developing results on more distant quasars using Keck Observatory and ALMA.