black hole feedback Archives

June 24, 2024June 24, 2024 by Evan Gough

Growing Black Holes Have Much in Common With Baby Stars

Assisted by magnetic fields, a spiraling wind helps the supermassive black hole in galaxy ESO320-G030 grow. In this illustration, the core of the galaxy is dominated by a rotating wind of dense gas leading outwards from the (hidden) supermassive black hole at the galaxy’s center. The motions of the gas, traced by light from molecules of hydrogen cyanide, have been measured with the Atacama Large Millimeter/submillimeter Array. Image credit: M. D. Gorski/Aaron M. Geller, Northwestern University, CIERA, the Center for Interdisciplinary Exploration and Research in Astrophysics.

First looks would tell most observers that supermassive black holes (SMBHs) and very young stars have nothing in common. But that’s not true. Astronomers have detected a supermassive black hole (SMBH) whose growth is regulated the same way a baby star’s is: by magnetic winds.

February 7, 2024February 7, 2024 by Evan Gough

A Black Hole Has Cleared Out Its Neighbourhood

An artist's illustration of a supermassive black hole (SMBH.) The SMBH in a distant galaxy expelled all the material in its accretion disk, clearing out a vast area. Image Credit: ESA

We can’t see them directly, but we know they’re there. Supermassive black holes (SMBHs) likely dwell at the center of every large galaxy. Their overwhelming gravity draws material toward them, where it collects in an accretion disk, waiting its turn to cross the event horizon into oblivion.

But in one galaxy, the SMBH has choked on its meal and spit it out, sending material away at high speeds and clearing out the entire neighbourhood.

August 18, 2023August 18, 2023 by Evan Gough

This Distant Galaxy Cluster is Totally Relaxed, Unharassed for a Billion Years

Astronomers have discovered a galaxy cluster with an important characteristic; it's “relaxed, meaning that it shows no signs of having been disrupted by violent collisions with other clusters of galaxies. This composite image contains X-rays from Chandra (blue), which helped identify SPT2215 along with other telescopes, and data from Hubble (cyan and orange). Image Credit: X-ray: NASA/CXC/MIT/M. Calzadilla; UV/Optical/Near-IR/IR: NASA/STScI/HST; Image processing: N. Wolk

In the span of a human lifetime, much of the Universe seems unchanging. But that’s an illusion; things are always changing, and that fact can make galaxies and the clusters they reside in very unruly places due to mergers and collisions.

However, some galaxy clusters seem much calmer than others.

January 18, 2023January 18, 2023 by Evan Gough

The Donut That Used To Be a Star

This sequence of artist's illustrations shows how a black hole can devour a bypassing star. 1) A normal star passes near a supermassive black hole in the center of a galaxy. 2) The star's outer gasses are pulled into the black hole's gravitational field. 3) The star is shredded as tidal forces pull it apart. 4) The stellar remnants are pulled into a donut-shaped ring around the black hole, and will eventually fall into the black hole, unleashing a tremendous amount of light and high-energy radiation. Credit: NASA, ESA, Leah Hustak (STScI)

The death of a star is one of the most dramatic natural events in the Universe. Some stars die in dramatic supernova explosions, leaving nebulae behind as shimmering remnants of their former splendour. Some simply wither away as their hydrogen runs out, billowing into a red giant as they do so.

But others are consumed by behemoth black holes, and as they’re destroyed, the black hole’s powerful gravity tears the star apart and draws its gas into a donut-shaped ring around the black hole.