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 four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work ''The Rea ...

approximately 57 million

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 101 ...

s away in the equatorial constellation of

Virgo Virgo may refer to: * Virgo (astrology), the sixth astrological sign of the zodiac * Virgo (constellation), a constellation * Virgo Cluster, a cluster of galaxies in the constellation Virgo * Virgo Stellar Stream, remains of a dwarf galaxy *Virgo ...

. 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 equatorial constellation of Virgo. It is a member of the Virgo Cluster, with the nearest fellow member away and around 5 magnitudes fainter. The nearest cluster member o ...

were discovered by Johann Gottfried Koehler in April 1779, observing a

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

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''. Messier's purpose f ...

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 type of galaxy intermediate between an elliptical (denoted E) and a spiral galaxy in galaxy morphological classification schemes. It contains a large-scale disc but does not have large-scale spiral arms. ...

. An E2 class indicates a

flattening Flattening is a measure of the compression of a circle or sphere A sphere () is a Geometry, geometrical object that is a solid geometry, three-dimensional analogue to a two-dimensional circle. A sphere is the Locus (mathematics), set o ...

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. The galaxy has an effective radius 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 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 ...

. 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 obj ...

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

inactive Inactive is a TRPV channel in invertebrates Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping ...

. 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 most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may ...

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

Supernovae

In 2004, supernova '' SN 2004W'' was observed in Messier 60. It was a type 1a supernova 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, 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. The cosmological evolution of the void regions differs drastically from the evolut ...

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

which he included ( Messier 85, 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 they are, the faster they are moving ...

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