NGC 4111 is alenticular galaxy in the constellationCanes Venatici. It is located at a distance of circa 50 millionlight-years from Earth, which, given its apparent dimensions, means that NGC 4111 is about 55,000 light-years across. It was discovered byWilliam Herschel in 1788. NGC 4111 possesses both thin and thickdiscs.[2]
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.[3] 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 be108M☉. The ring can provide enough material for anactive galactic nucleus and for circumnuclear star formation.[4] The galaxy also possesses an X-shaped, (peanut shell)-shaped bulge,[5] 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 itsmetallicity is subsolar.[6]
The nucleus of the galaxy features alow-ionization nuclear emission-line region (LINER), which is emittingX-rays. The nucleus is the only source that was identified in observations byChandra X-ray Observatory[7] 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 luminosityactive galactic nucleus.[8]
NGC 4111 appears disturbed inHI 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 galaxiesNGC 4117 andNGC 4118,[11] which lie 7 arcminutes to east-northeast.[12]
^Hauschild Roier, Gabriel R; Storchi-Bergmann, Thaisa; McDermid, Richard M; Walsh, Jonelle L; Tan, Joanne; Cohn, Jonathan; Krajnovic, Davor; Greene, Jenny; Valluri, Monica; Gültekin, Kayhan; Thater, Sabine; van de Ven, Glenn; Gebhardt, Karl; Lützgendorf, Nora; Boizelle, Benjamin D; Ma, Chung-Pei; Barth, Aaron J (29 March 2022)."Gas inflows in the polar ring of NGC 4111: the birth of an AGN".Monthly Notices of the Royal Astronomical Society.512 (2):2556–2572.doi:10.1093/mnras/stac634.hdl:10183/239481.
