Messier 60 or M60, also known as NGC 4649, is an

elliptical galaxy An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the three main galaxy morphological classification, classes of galaxy described by Edwin Hubble in his Hub ...

approximately 57 million

light-year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astr ...

s away in the equatorial

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

Virgo Virgo may refer to: Arts and entertainment * Virgo (film), a 1970 Egyptian film * Virgo (character), several Marvel Comics characters * Virgo Asmita, a character in the manga ''Saint Seiya: The Lost Canvas'' * ''Virgo'' (album), by Virgo Four, ...

. Together with NGC 4647, it forms a pair known as Arp 116. Messier 60 and nearby elliptical galaxy

Messier 59 Messier 59 or M59, also known as NGC 4621, is an elliptical galaxy in the celestial equator, equatorial constellation of Virgo (constellation), Virgo. It is a member of the Virgo Cluster, with the nearest fellow member away and around 5 magnitud ...

were discovered by

Johann Gottfried Koehler Johann, typically a male given name, is the German form of ''Iohannes'', which is the Latin form of the Greek name ''Iōánnēs'' (), itself derived from Hebrew name '' Yochanan'' () in turn from its extended form (), meaning "Yahweh is Graciou ...

in April 1779, observing a

comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...

in the same part of the sky.

Charles Messier Charles Messier (; 26 June 1730 – 12 April 1817) was a French astronomer. He published an astronomical catalogue consisting of 110 nebulae and star clusters, which came to be known as the ''Messier objects'', referred to with th ...

added both to his catalogue about three days after this.

Characteristics

This is an elliptical galaxy of type E (E1.5), although some sources class it as S0 – a

lenticular galaxy A lenticular galaxy (denoted S0) is a Galaxy morphological classification, type of galaxy intermediate between an elliptical galaxy, elliptical (denoted E) and a spiral galaxy in galaxy morphological classification schemes. It contains a large-s ...

. An E2 class indicates a

flattening Flattening is a measure of the compression of a circle or sphere along a diameter to form an ellipse or an ellipsoid of revolution (spheroid) respectively. Other terms used are ellipticity, or oblateness. The usual notation for flattening is f ...

of 20%, which has a nearly round appearance. The

isophote In geometry, an isophote is a curve on an illuminated surface that connects points of equal brightness. One supposes that the illumination is done by parallel light and the brightness is measured by the following scalar product: :b(P)= \vec n(P) ...

s of the galaxy are boxy in shape, rather than simple ellipses. The

mass-to-light ratio In astrophysics and physical cosmology the mass-to-light ratio, normally designated with the Greek letter upsilon, , is the quotient between the total mass of a spatial volume (typically on the scales of a galaxy or a cluster) and its luminosity. ...

is a near constant 9.5 in the V (visual) band of the

UBV system __NOTOC__ The UBV photometric system (from ''Ultraviolet, Blue, Visual''), also called the Johnson system (or Johnson-Morgan system), is a photometric system usually employed for classifying stars according to their colors. It was the first stan ...

. The galaxy has an

effective radius In applied sciences, the equivalent radius (or mean radius) is the radius of a circle or sphere with the same perimeter, area, or volume of a non-circular or non-spherical object. The equivalent diameter (or mean diameter) (D) is twice the equiva ...

of (translating, at its distance, to about 10 kpc), with an estimated mass of ~10¹² within a threefold volume, of which nearly half is

dark matter In astronomy, dark matter is an invisible and hypothetical form of matter that does not interact with light or other electromagnetic radiation. Dark matter is implied by gravity, gravitational effects that cannot be explained by general relat ...

. The mass estimated from X-ray emission is within 5 effective radii.

Supermassive black hole

At the center of M60 is a

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical ...

(SMBH) of billion solar masses, one of the largest ever found. It is currently

inactive Inactive is a TRPV channel in invertebrates Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including ...

. X-ray emission from the galaxy shows a cavity created by jets emitted by the hole during past active periods, which correspond to weak radio lobes. The

power Power may refer to: Common meanings * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power, a type of energy * Power (social and political), the ability to influence people or events Math ...

needed to generate these features is in the range (ergs per second).

Supernovae

In 2004,

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

'' SN 2004W'' was observed in Messier 60. It was a

type Ia supernova A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...

found west and south of the nucleus.

Environment

M60 is the third-brightest giant elliptical galaxy of the Virgo cluster of galaxies, and is the dominant member of a subcluster of four galaxies, the M60 group, which is the closest-known isolated compact group of galaxies. It has several satellite galaxies, one of them being the ultracompact dwarf galaxy

M60-UCD1 M60-UCD1 is an ultracompact dwarf galaxy. It is 49 million light years from Earth, close to Messier 60 (M60, NGC 4649) in the Virgo Cluster. Half of its stellar mass is in the central sphere 160 light years in diameter. Characteristics M60-UCD ...

, discovered in 2013. The motion of M60 through the

intercluster medium Cosmic voids (also known as dark space) are vast spaces between filaments (the largest-scale structures in the universe), which contain very few or no galaxies. In spite of their size, most galaxies are not located in voids. This is because ...

is resulting in

ram-pressure stripping Ram pressure is a pressure exerted on a body moving through a fluid medium, caused by relative bulk motion of the fluid rather than random thermal motion. It causes a drag force to be exerted on the body. Ram pressure is given in tensor form as ...

of gas from the galaxy's outer halo, beyond a radius of 12 kpc. NGC 4647 appears approximately 2.5 from Messier 60; the optical disks of the two galaxies overlap. Although this overlap suggests that the galaxies are interacting, photographic images of the two galaxies do not reveal any evidence for gravitational interactions between the two galaxies as would be suggested if the two galaxies were physically close to each other. This suggests that the galaxies are at different distances and are only weakly interacting if at all. However, studies with the Hubble Space Telescope show indications that a tidal interaction may have just begun.

Recession speed and distance estimations

Messier 60 was the fastest-moving galaxy included in

Edwin Hubble Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology. Hubble proved that many objects previously ...

's landmark 1929 paper concerning the relationship between recession speed and distance. He used a value of 1090 km/s for the recession speed, 1.8% less than the more recent value of about 1110 km/s (based on a redshift of 0.003726). But he estimated the distance of this galaxy as well as of the three nebulas of the

Virgo Cluster The Virgo Cluster is a cluster of galaxies whose center is 53.8 ± 0.3 Mly (16.5 ± 0.1 Mpc) away in the Virgo constellation. Comprising approximately 1,300 (and possibly up to 2,000) member galaxies, the cluster forms the heart of the larger ...

which he included (

Messier 85 Messier 85 (also known as M85 or NGC 4382 or PGC 40515 or ISD 0135852) is a lenticular galaxy, or elliptical galaxy for other authors, in the Coma Berenices constellation. It is 60 million light-years away, and has a diameter of about across. ...

, 49, and 87), to be only two million parsecs, rather than the accepted value today of around 16 million parsecs. These errors in distance led him to propose a

Hubble constant Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther a galaxy is from the Earth, the faste ...

of 500 km/s/Mpc, whereas the present estimate is around 70 km/s/Mpc.

Gallery

File:Arp116 Hubble.jpg, Arp 116 is composed of a giant elliptical galaxy known as Messier 60, and a much smaller spiral galaxy, NGC 4647.

References

External links

StarDate: M60 Fact Sheet
* {{DEFAULTSORT:Messier 60 Messier 060 Messier 060 Messier 060 Messier 060 Messier 060 060 Messier 060 07898 42831 116 Astronomical objects discovered in 1779