galaxies Archives

December 12, 2019December 12, 2019 by Evan Gough

How Spiral Galaxies Get Their Shape

Magnetic fields in NGC 1086, or M77, are shown as streamlines over a visible light and X-ray composite image of the galaxy from the Hubble Space Telescope, the Nuclear Spectroscopic Array, and the Sloan Digital Sky Survey. The magnetic fields align along the entire length of the massive spiral arms — 24,000 light years across (0.8 kiloparsecs) — implying that the gravitational forces that created the galaxy’s shape are also compressing the its magnetic field. This supports the leading theory of how the spiral arms are forced into their iconic shape known as “density wave theory.” SOFIA studied the galaxy using far-infrared light (89 microns) to reveal facets of its magnetic fields that previous observations using visible and radio telescopes could not detect. Credits: NASA/SOFIA; NASA/JPL-Caltech/Roma Tre Univ.

Spiral galaxies are an iconic form. They’re used in product logos and all sorts of other places. We even live in one. And though it may seem kind of obvious how they get their shape, by rotating, that’s not the case.

December 5, 2019December 5, 2019 by Evan Gough

There’s a New Record for the Most Massive Black Hole Ever Seen: 40 Billion Solar Masses

Image of Abell 85 cluster of galaxies obtained at the USM Wendelstein observatory of the Ludwig-Maximilians-University. The central bright galaxy Holm15A has an extended core. A team of astronomers at the Max Planck Institute for Extraterrestrial Physics and the University Observatory Munich were able to use new data to directly measure the mass of central black hole of this galaxy: it is 40 billion times more massive than our Sun. Image Credit: Matthias Kluge/USM/MPE

Astronomers have spotted a 40 billion solar mass black hole in the Abell 85 cluster of galaxies. They found the behemoth using spectral observations with the Very Large Telescope (VLT.) There are only a few direct mass measurements for black holes, and at about 700 million light years from Earth, this is the most distant one.

November 25, 2019November 25, 2019 by Evan Gough

Astronomers Find a Galaxy Containing Three Supermassive Black Holes at the Center

Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. NGC 6240 is the result of three galaxies merging. Image Credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

NGC 6240 is a puzzle to astronomers. For a long time, astronomers thought the galaxy is a result of a merger between two galaxies, and that merger is evident in the galaxy’s form: It has an unsettled appearance, with two nuclei and extensions and loops.

October 19, 2019October 19, 2019 by Matt Williams

The Most Massive Galaxies Spin More Than Twice as Fast as the Milky Way

Hubble Space Telescope image of Messier 77 spiral galaxy. A version of this image won second place in the Hubble’s Hidden Treasures Image Processing Competition. Image: NASA, ESA & A. van der Hoeven, 2013

It’s a difficult thing to wrap your head around sometimes. Though it might feel stationary, planet Earth is actually moving at an average velocity of 29.78 km/s (107,200 km/h; 66600 mph). And yet, our planet has nothing on the Sun itself, which travels around the center of our galaxy at a velocity of 220 km/s (792,000 km/h; 492,000 mph).

But as is so often the case with our Universe, things only get more staggering the farther you look. According to a new study by an international team of astronomers, the most massive “super spiral” galaxies in the Universe rotate twice as fast as the Milky Way. The cause, they argue, is the massive clouds (or halos) of Dark Matter that surround these galaxies.

September 27, 2019September 27, 2019 by Evan Gough

Astronomers Have Found a Place With Three Supermassive Black Holes Orbiting Around Each Other

The three black holes at the center of three separate galaxies as imaged by Chandra and other telescopes. Image Credit: Credit: X-ray: NASA/CXC/George Mason Univ./R. Pfeifle et al.; Optical: SDSS & NASA/STScI

Astronomers have spotted three supermassive black holes (SMBHs) at the center of three colliding galaxies a billion light years away from Earth. That alone is unusual, but the three black holes are also glowing in x-ray emissions. This is evidence that all three are also active galactic nuclei (AGN,) gobbling up material and flaring brightly.

This discovery may shed some light on the “final parsec problem,” a long-standing issue in astrophysics and black hole mergers.

September 23, 2019September 23, 2019 by Evan Gough

Elliptical Galaxy Messier 110 Has a Surprising Core of Hot Blue Stars

A new Hubble image of M 110 shows that these dwarf elliptical galaxies do contain some blue, hot young stars and that they may harbour areas of star formation after all. Image credit: ESA/Hubble & NASA, L. Ferrarese et al.

Messier 110 (NGC 205) is a satellite of the Andromeda Galaxy. It’s a dwarf elliptical galaxy, a common type of galaxy often found in galaxy clusters and groups, and it contains about 10 billion stars. Like all dwarf ellipticals, it doesn’t have the characteristic shape of galaxies like Andromeda or the Milky Way, with their vast, spiral arms. It has a smooth, featureless shape.

Dwarf ellipticals lack the blazing bright areas of active star formation that other galaxies display. In fact, astronomers think that they’re too old to have any young stars at all. But M110 appears to be different.

August 12, 2019August 12, 2019 by Matt Williams

Astronomers Uncover Dozens of Previously Unknown Ancient and Massive Galaxies

The ALMA array in Chile. Once ALMA was added to the Event Horizon Telescope, it increased the EHT's power by a factor of 10. Image: ALMA (ESO/NAOJ/NRAO), O. Dessibourg

For decades, astronomers have been trying to see as far as they can into the deep Universe. By observing the cosmos as it was shortly after the Big Bang, astrophysicists and cosmologists hope to learn all they can about the early formation of the Universe and its subsequent evolution. Thanks to instruments like the Hubble Space Telescope, astronomers have been able to see parts of the Universe that were previously inaccessible.

But even the venerable Hubble is incapable of seeing all that was taking place during the early Universe. However, using the combined power of some of the newest astronomical observatories from around the world, a team of international astronomers led by Tokyo University’s Institute of Astronomy observed 39 previously-undiscovered ancient galaxies, a find that could have major implications for astronomy and cosmology.

August 10, 2019August 10, 2019 by Evan Gough

A Monster Black Hole has been Found with 40 Billion Times the Mass of the Sun

A composite image of the Abell 85 galaxy cluster. The purple is multi-million degree gas detected in X-rays by NASA's Chandra X-ray Observatory and the other colors show galaxies in an optical image from the Sloan Digital Sky Survey. Image Credit: X-ray (NASA/CXC/SAO/A.Vikhlinin et al.); Optical (SDSS); Illustration (MPE/V.Springel)

If contemplating the vast size of astronomical objects makes you feel rather puny and insignificant, then this new discovery will make you feel positively infinitesimal.

It’s almost impossible to imagine an object this large: a super massive black hole that’s 40 billion times more massive than our Sun. But there it is, sitting in the center of a super-giant elliptical galaxy called Holmberg 15A. Holmberg 15A is about 700 million light years away, in the center of the Abell 85 galaxy cluster.

July 22, 2019July 22, 2019 by Evan Gough

Meet Our Neighbour, The Local Void. Gaze Into It, Puny Humans.

A smoothed rendition of the structure surrounding the Local Void. Our Milky Way galaxy lies at the origin of the red-green-blue orientation arrows (each 200 million lightyears in length). We are at a boundary between a large, low density void, and the high density Virgo cluster. Credit: R. Brent Tully

Our planet is part of the larger structure of the Solar System, shaped and made stable by the force of gravity. Our Solar System is gravitationally bound to the Milky Way galaxy, along with hundreds of millions of other solar systems. And our galaxy is also part of a larger structure, where not only gravity, but the expansion of the Universe, shapes and molds that structure. For regular Universe Today readers, none of that is news.

Now a new study sheds some light on a curious part of our cosmic neighbourhood, where there is basically nothing: The Local Void.

July 15, 2019July 15, 2019 by Matt Williams

Hubble Spots “Impossible” Debris Disk Around a Black Hole

The Hubble Space Telescope is like an old dog that is constantly teaching the astronomical community new tricks. In the course of its almost thirty years in operation, it has revealed vital data about the expansion of the Universe, its age, the Milky Way, supermassive black holes (SMBHs), other star systems and exoplanets, and the planets of the Solar System.

Most recently, an international team of researchers using Hubble made a discovery that was not only fascinating but entirely unexpected. In the heart of the spiral galaxy NGC 3147, they spotted a swirling thin disk of gas that was precariously close to a back hole that is about 250 million Solar masses. The find was a complete surprise since the black hole was considered too small to have such a structure around it.