The Musket Ball Cluster (DLSCL J0916.2+2951) is a
galaxy cluster
A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-la ...
that exhibits separation between its
baryonic matter
In particle physics, a baryon is a type of composite subatomic particle which contains an odd number of valence quarks (at least 3). Baryons belong to the hadron family of particles; hadrons are composed of quarks. Baryons are also classifi ...
and
dark matter
Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not ab ...
components. The cluster is a recent merger of two galaxy clusters. It is named after the
Bullet Cluster, as it is a slower collision, and older than the Bullet Cluster. This cluster is further along the process of merger than the Bullet Cluster,
being some 500
million years
The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds.
Usage
Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...
older, at 700 million years old.
The cluster was discovered in 2011 by the
Deep Lens Survey
The Deep Lens Survey (DLS, short for "Deep Gravitational Lensing Survey") is an ultra-deep multi-band optical survey of seven 4 square degree fields. Mosaic CCD imagers at the National Optical Astronomy Observatory's Blanco (Cerro Tololo) and Ma ...
.
As of 2012, it is one of the few galaxy clusters to show separation between its dark matter and baryonic matter components.
[ ]
Characteristics
As of 2012, it is one of seven galaxy clusters that exhibit separation of dark matter and baryonic matter following cluster collision and merger.
[ The separation between the galaxies and their dark matter components is on average . This separation may indicate that dark matter may interact with itself, through a dark force (a force that only interacts with dark matter) or a set of dark forces.]
See also
* Bullet Group
The Bullet Group (SL2S J08544-0121) is a newly merging group of galaxies, a merger between two galaxy groups to form a new larger one, that recently had a high speed collision between the two component groups. The group exhibits separation betwe ...
;Other dissociative galaxy cluster mergers known at time of discovery
* Bullet Cluster (2006)
* MACS J0025.4-1222 (2008)
* Abell 520
The Abell 520 galaxy cluster possesses an unusual substructure resulting from a major merger. It has been popularly nicknamed The Train Wreck Cluster, due to its chaotic structure, and is classified as a Bautz-Morgan type III cluster. It is a ...
(2007)
* Abell 2744
Abell 2744, nicknamed Pandora's Cluster, is a giant galaxy cluster resulting from the simultaneous pile-up of at least four separate, smaller galaxy clusters that took place over a span of 350 million years, and is located approximately 4 billion ...
(2011)
* Abell 2163
Abell 2163 is one of the richest and most distant of the clusters of galaxies found in the Abell catalogue. Its abell richness class is 2 and position is at a redshift z=0.2. Data from Chandra X-ray Observatory have shown that it is the hottest g ...
(2011)
* Abell 1759 Abell may refer to:
People
*Abell (surname)
*George O. Abell, of the astronomical catalogues fame
Places
;United States
* Abell, Maryland, a location in St. Mary's County, Maryland
* Abell, a neighborhood in Baltimore, Maryland
* Abells Corners, ...
(2011)
References
External links
* Chandra X-Ray Observatory
"Musket Ball Cluster in 60 Seconds"
April Hobart, 16 April 2012 (PODcast)
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Galaxy clusters
Cancer (constellation)