Finding Dark Matter
19.12.2001

Where is dark matter? Galaxies rotate and move in clusters as if a tremendous amount of unseen matter is present. But does dark matter exist in the greater universe too -- and if so, where? The answer can be found by comparing the distribution of galaxies observed with numerical simulations.

A Quasar-Galaxy Collision?
22.10.1995

In 1963 astronomers were astounded to discover that certain faint, star-like objects have very large redshifts. The large redshifts imply that these objects, now known as quasars (QUASi-stellAR objects), lie near the edge of the observable Universe.

The Sloan Great Wall: Largest Known Structure
7.11.2007

What is the largest structure known? The answer might depend on how one defines "structure." A grouping of galaxies known as the Sloan Great Wall was discovered in the Sloan Digital Sky Survey and is a leading candidate.

Time Tunnel
6.09.2007

Spiky stars are nearby, but fuzzy galaxies are strewn far across the Universe in this cosmic view. Spanning about 1/2 degree on the sky, the pretty picture is the result of astronomer Johannes Schedler's project to look back in time, toward a quasar 12.7 billion light-years away.

APOD: 2023 May 31 Б Simulation: A Disk Galaxy Forms
31.05.2023

How did we get here? We know that we live on a planet orbiting a star orbiting a galaxy, but how did all of this form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out.

APOD: 2023 July 5 Б A Map of the Observable Universe
5.07.2023

What if you could see out to the edge of the observable universe? You would see galaxies, galaxies, galaxies, and then, well, quasars, which are the bright centers of distant galaxies. To expand understanding...

Earendel: A Star in the Early Universe
6.04.2022

Is Earendel the farthest star yet discovered? This scientific possibility started when the Hubble Space Telescope observed a huge cluster of galaxies. The gravitational lens effectбof this cluster was seen to magnify and distort a galaxy far in the background.

Galaxy Formation in a Magnetic Universe
19.02.2018

How did we get here? We know that we live on a planet orbiting a star orbiting a galaxy, but how did all of this form? To understand details better, astrophysicists upgraded the famous Illustris Simulation into IllustrisTNG -- now the most sophisticated computer model of how galaxies evolved in our universe.

UHZ1: Distant Galaxy and Black Hole
10.11.2023

Dominated by dark matter, massive cluster of galaxies Abell 2744 is known to some as Pandora's Cluster. It lies 3.5 billion light-years away toward the constellation Sculptor. Using the galaxy cluster's enormous...

JKCS041: The Farthest Galaxy Cluster Yet Measured
28.10.2009

What if we could see back to the beginning of the universe? We can -- since it takes the age of the universe for light to cross the universe. Peering at distant objects, therefore, tells us about how the universe used to be, even near its beginning.