AI Insight
Astronomers analyzed 2,435 galaxies with actively feeding black holes using the Dark Energy Spectroscopic Instrument and found that 546 of these galaxies lack a central stellar bulge. The research demonstrates that black holes in bulgeless galaxies grow just as effectively as those in galaxies with prominent bulges, challenging the conventional view that violent galaxy mergers are necessary for normal black hole growth.
Why it matters
This finding reshapes our understanding of black hole evolution by showing that supermassive black holes can develop through quieter, continuous processes rather than requiring dramatic collision events. It suggests black hole growth may be a more gradual and common phenomenon throughout cosmic history than previously thought.
Understand the Science
Astronomers analyzed 2,435 galaxies hosting actively feeding black holes using data from the Dark Energy Spectroscopic Instrument (DESI). Among them, they identified 546 “bulgeless” galaxies—systems with little or no central stellar bulge. Their paper, published in Monthly Notices of the Royal Astronomical Society, suggests that galaxies without a central bulge grow black holes just as effectively as galaxies that have one—a surprising sign that black holes don’t need galaxy mergers to grow normally.
Source: Black holes may grow quietly alongside galaxies even without violent mergers