massive black hole tagged posts

In late 2019 the previously unremarkable galaxy SDSS1335+0728 suddenly started shining brighter than ever before. To understand why, astronomers have used data from several space and ground-based observatories, including the European Southern Observatory’s Very Large Telescope (ESO’s VLT), to track how the galaxy’s @brightness has varied. In a study out today, they conclude that they are witnessing changes never seen before in a galaxy – likely the result of the sudden awakening of the massive black hole at its core.

“Imagine you’ve been observing a distant galaxy for years, and it always seemed calm and inactive,” says Paula Sánchez Sáez, an astronomer at ESO in Germany and lead author of the study accepted for publication in Astronomy & Astrophysics...

Astronomers at The University of Texas at Austin’s McDonald Observatory have discovered an unusually massive black hole at the heart of one of the Milky Way’s dwarf satellite galaxies, called Leo I. Almost as massive as the black hole in our own galaxy, the finding could redefine our understanding of how all galaxies — the building blocks of the universe — evolve. The work is published in a recent issue of The Astrophysical Journal.

The team decided to study Leo I because of its peculiarity. Unlike most dwarf galaxies orbiting the Milky Way, Leo I does not contain much dark matter. Researchers measured Leo I’s dark matter profile — that is, how the density of dark matter changes from the outer edges of the galaxy all the way into its center...

It was previously thought that collisions between galaxies would necessarily add to the activity of the massive black holes at their centers. However, researchers have performed the most accurate simulations of a range of collision scenarios and have found that some collisions can reduce the activity of their central black holes. The reason is that certain head-on collisions may in fact clear the galactic nuclei of the matter which would otherwise fuel the black holes contained within.

When you think about gargantuan phenomena such as the collision of galaxies, it might be t...

Illustration of emissions from a tidal disruption event shows in cross section what happens when the material from a disrupted star is devoured by a black hole. The material forms an accretion disk, which heats up and emits vast amounts of light and radiation. The emissions we are able to see from Earth depend on our viewing angle with respect to the orientation of the black hole. Credit: Illustration by Jane Lixin Dai

A star that wanders too close to the supermassive black hole in the center of its galaxy will be torn apart by the black hole’s gravity in a violent cataclysm called a tidal disruption event (TDE), producing a bright flare of radiation...