NGC 4111 is 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 ...

in the constellation

Canes Venatici Canes Venatici ( ) is one of the 88 constellations designated by the International Astronomical Union (IAU). It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for 'hunting dogs', and ...

. It is located at a distance of circa 50 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 from Earth, which, given its apparent dimensions, means that NGC 4111 is about 55,000 light-years across. It was discovered by

William Herschel Frederick William Herschel ( ; ; 15 November 1738 – 25 August 1822) was a German-British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel. Born in the Electorate of Hanover ...

in 1788. NGC 4111 possesses both thin and thick discs.

Characteristics

The galaxy is characterised by a series of dusty filaments running through its centre. They are associated with a ring of material encircling the galaxy's core, which is not aligned with the galaxy's main disc, suggesting that this polar ring of gas and dust is actually the remains of a smaller galaxy. The polar ring has a diameter of 450 pc and in it is embedded one with a diameter of 220 pc visible in H₂1-0 imaging. The estimated cold molecular gas mass within the polar ring is estimated to be . The ring can provide enough material for an

active galactic nucleus An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. Such e ...

and for circumnuclear star formation. The galaxy also possesses an X-shaped, (peanut shell)-shaped bulge, thought to arise from an unstable stellar bar. The stellar population within the disk is quite young (2 ±0.3 billion years mean age) and its

metallicity In astronomy, metallicity is the Abundance of the chemical elements, abundance of Chemical element, elements present in an object that are heavier than hydrogen and helium. Most of the normal currently detectable (i.e. non-Dark matter, dark) matt ...

is subsolar. The nucleus of the galaxy features a

low-ionization nuclear emission-line region A low-ionization nuclear emission-line region (LINER) is a type of galactic nucleus that is defined by its spectral line emission. The spectra typically include line emission from weakly ionized or neutral atoms, such as O, O+, N+, and S ...

(LINER), which is emitting

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

s. The nucleus is the only source that was identified in observations by

Chandra X-ray Observatory The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources ...

and there was also diffuse emission. The central sources accounts for approximately 77% of the hard X-rays emission of the galaxy. Its central source has also been detected in radiowaves and is believed to be a low luminosity

Nearby galaxies

NGC 4111 is the foremost galaxy in NGC 4111

galaxy group A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxi ...

, one of the subgroups of

Ursa Major Cluster The Ursa Major Cluster (Ursa Major I Cluster, UMa I ClG) is a spiral-rich galaxy cluster of the Virgo Supercluster. Some of its largest members are NGC 3631, NGC 3953, M109 on North (M109 Group) and NGC 3726, NGC 3938, NGC 4051 on South. ...

. The NGC 4111 Group is the second most massive subgroup, after the

M109 Group The M109 Group (also known as the NGC 3992 Group or Ursa Major cloud) is a group of galaxies about 55 million light-years away in the constellation Ursa Major. The group is named after the brightest galaxy within the group, the spiral galaxy ...

. According with Makarov and Karachentsev, members of the NGC 4111 Group are the galaxies UGC 6818,

NGC 3938 NGC 3938 is an unbarred spiral galaxy in the Ursa Major constellation. It was discovered by German-British astronomer William Herschel on 6 February 1788. It is one of the brightest spiral galaxies in the Ursa Major South galaxy group and is ro ...

NGC 4013 NGC 4013 is an edge-on barred spiral galaxy about 1 E23 m, 55 million light-years away in the constellation Ursa Major. The disk of NGC 4013 shows a distinct "peanut"-shaped bulge in long exposure photographs that N-body computer simulations sugg ...

, IC 749, IC 750,

NGC 4051 NGC 4051 is an intermediate spiral galaxy in the constellation of Ursa Major. It was discovered on 6 February 1788 by John Herschel. NGC 4051 contains a supermassive black hole with a mass of 1.73 million . This galaxy was studied by the Multic ...

, UGC 7089, UGC 7094, NGC 4117, NGC 4138 and NGC 4183. NGC 4111 appears disturbed in HI imaging, with HI extending 28 arcminutes south of the central position of NGC 4111, which corresponds in 120 kpc if the distance is 15 Mpc, and connects NGC 4111 with the nearby galaxies NGC 4117 and NGC 4118, which lie 7 arcminutes to east-northeast.

References

External links

{{DEFAULTSORT:NGC 4111 Lenticular galaxies Canes Venatici 4111 07103 38440 NGC 4111 Group Discoveries by William Herschel