NGC 541 is 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. L ...

located in the constellation

Cetus Cetus () is a constellation, sometimes called 'the whale' in English. The Cetus (mythology), Cetus was a sea monster in Greek mythology which both Perseus and Heracles needed to slay. Cetus is in the region of the sky that contains other water- ...

. It is located at a distance of circa 230 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 1012 ...

s from Earth, which, given its apparent dimensions, means that NGC 541 is about 130,000 light years across. It was discovered by

Heinrich d'Arrest Heinrich Louis d'Arrest (13 August 1822 – 14 June 1875; ) was a Germans, German astronomer, born in Berlin. His name is sometimes given as Heinrich Ludwig d'Arrest. Biography While still a student at the Humboldt University of Berli ...

on October 30, 1864. It is a member of the Abell 194 galaxy cluster and is included in the

Atlas of Peculiar Galaxies The ''Atlas of Peculiar Galaxies'' is a catalog of peculiar galaxies produced by Halton Arp in 1966. A total of 338 galaxies are presented in the atlas, which was originally published in 1966 by the California Institute of Technology. The p ...

in the category galaxies with nearby fragments. NGC 541 is a

radio galaxy A radio galaxy is a galaxy with giant regions of radio emission extending well beyond its visible structure. These energetic radio lobes are powered by jets from its active galactic nucleus. They have luminosities up to 1039 W at radio wa ...

of Fanaroff-Riley class I, also known as 3C 40A (3C 40B is more prominent and is associated with the nearby galaxy NGC 547). The galaxy was observed by the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

. It was found that it has a central disk seen nearly face-on with a diameter of 1".8. Inside the disk is an inner ring with a diameter of circa 0".44 arcseconds, maybe part of a hardly visible spiral structure. There is also a linear dust feature sticking out of the disk with nearly the same axis as the radio jet.

H-alpha H-alpha (Hα) is a specific deep-red visible spectral line in the Balmer series with a wavelength of 656.28 nm in air and 656.46 nm in vacuum; it occurs when a hydrogen electron falls from its third to second lowest energy level. H-alph ...

and IIemission presented a peak at the centre of the dusk disk and also was found to form a ring around the peak, which had two brighter spots lying diametrically opposed. Observations in CO emission revealed the presence of molecular gas in NGC 541, with estimated mass of approximately 10⁸ , and with a compact ring-like distribution with a radius of 1-2 kpc. In the centre of NGC 541 lies 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 ...

whose mass is estimated to be (1.9 – 9.2) × 10⁸ . At 45 arcseconds northeast of NGC 541 lies an irregular dwarf galaxy known as Minkowski's object. It is located in the path of the radio jet of NGC 541 and there is strong evidence that the jet has caused a starburst in Minkowski's object. There is a HI region downstream from the Minkowski's object with that straddles the jet at the point where the jet changes direction. At least 20 regions with

star cluster Star clusters are large groups of stars. Two main types of star clusters can be distinguished: globular clusters are tight groups of ten thousand to millions of old stars which are gravitationally bound, while open clusters are more loosely clust ...

s and associated

HII region An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds ...

s have been detected in Minkowski's object. The stellar population in Minkowski's object is dominated by stars formed in a single event 7.5 million years ago. The current starbirth rate is 0.52 per year. Although it has been proposed that Minkowski's object was a dwarf galaxy that happened to pass through the radio jet of NGC 541, it is more probable that the HI region was warm intergalactic gas that was cooled by the jet, resulting in star formation, a model that has been reproduced by computer stimulations. A stellar bridge has been detected between NGC 541 and the galaxy pair NGC 545/547, which lies 4.5 arcminutes to the northeast (projected distance circa 100 kpc).

References

External links

NGC 541 on SIMBAD
{{DEFAULTSORT:NGC 541 Lenticular galaxies Radio galaxies Cetus 0541 01004

133 133 may refer to: *133 (number) * AD 133 *133 BC *133 (song) *133 (New Jersey bus) 133 may refer to: *133 (number) * AD 133 *133 BC *133 (song) 133 may refer to: *133 (number) *AD 133 *133 BC *133 (song) *133 (New Jersey bus) 133 may refer to: * ...

005305 +00-04-137 Astronomical objects discovered in 1864