Web Results

Quasar - Wikipedia


A quasar is a compact region surrounding a supermassive black hole and emitting enormous .... Quasars inhabit the very center of active, young galaxies, and are among the most ... This implies an ex...

Galaxies - Astronomy Notes


May 1, 2013 ... This explains why galaxies are grouped in clusters and even clusters ... the elliptical galaxies while the lower density concentrations would ... stars that star- star collisions are very rare when the galaxies collide. ... found close to the centers of galaxies were formed from the collision and merging of galaxies.

Gravity, Part 4: Globular Clusters & Galaxies. - University of Michigan


Gravity, Part 4: Globular Clusters & Galaxies: The dynamics of globular ... this: all stars in the cluster move in Kepler orbits around the center of mass. ... Some sections of the galaxy have lots of stars (lots of mass per volume or high density); other ... to believe physical collisions between stars were extremely rare and ther...

Hubble views an old and mysterious cluster - Phys.org


Nov 14, 2013 ... This cluster of stars is known as Messier 15, and is located some 35 ... This glittering cluster contains over 100 000 stars, and could also hide a rare type ... or as a result of a collision between massive stars in dense clusters. ... Related Stories ... a globular star cluster located close to the center of the galax...

Can Stars Collide? - Universe Today


Dec 23, 2015 ... ... between stars are so vast that collisions are incredibly rare. ... The density of stars there is higher than anywhere else in the galaxy ... But if you live in a globular cluster or near the center of the galaxy, you ... Related posts.

New Data | Frontier Fields


Jun 29, 2016 ... A new Frontier Fields release from the Chandra X-ray Center highlights the energetic chaos that occurs when massive galaxy clusters collide. ... The galaxy cluster MACS J0416 seen in X-rays (blue), visible light (red, green, ... be observable without the benefit of magnification due to gravitational lensing.

Galaxies - SkyServer - SDSS


Stars, gas, and interstellar dust orbit the center of the galaxy due to the gravitational ... The Milky Way has more than a hundred billion stars, but the stars are so far apart that they almost never collide. ... ago, because galaxies are likely to have formed first in high-density regions like galaxy clusters. ... Irr II galaxies are...

astro-ph/0309303 PDF - arXiv.org


Jan 22, 2004 ... We compare new maps of the hot gas, dark matter, and galaxies for 1E 0657–56, a cluster with a rare, high- ... Subject headings: dark matter — galaxies: clusters: individual .... The surface density toward the subcluster center is several .... slowly diminishing due to DM collisions, its galaxies did not.

Chapter 15, Chapter Review


Astronomers also use studies of binary galaxies and galaxy clusters to obtain ... Galaxy collisions can occur, but are extremely rare. ... In the Tully—Fisher relation , a galaxy's luminosity is found to be related to the ______ of its spectral lines. ... 400 km/s in a circular orbit of radius 1 Mpc around the center of a galaxy clus...

Dark matter makes up 80% of the Universe—but where is it all? | Ars ...


Jul 27, 2014 ... While individual galaxy clusters usually can't tell us much, a large sample ... By contrast, the amount of dark matter increases toward the galaxy's center, so the density should be much higher in ... so that their (very rare) collisions result in mutual destruction and some high-energy photons. ... Related Stor...

More Info

Star Clusters and Stellar Dynamics


globular star clusters, galaxies, clusters of galaxies. • If 2-body ... Sometimes stars actually collide, but that happens only in the ... density distribution function, f(r,v,t) ... In a large stellar system, gravitational force at any point due .... the orbit than rare close encounters… .... of energy in the center, to replace the esc...

ch21 - NASA History Homepage


In sharp contrast are the spiral galaxies nearer to the center of the cluster. ... This trend continues into the core of the cluster, where spirals are rare. ... It seems to have been related to the efficiency with which stars were born ... They have shown that Virgo and other rich clusters are pervaded by a very hot low density gas.

Colliding galaxy clusters offer strongest case yet for dark matter | Ars ...


Mar 26, 2015 ... An image of the galaxy cluster MACS J0416.1–2403 with dark ... dark matter, collisions between clusters of galaxies provide a great testing ground. ... matter density toward the centers of galaxies and galaxy clusters, and ... If the interactions are rare but exchange a lot of momentum... dark ... Related Stories ....