NGC 1316 (also known as ''Fornax A'') is a lenticular galaxy about 60 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 away in the

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 origins of the e ...

Fornax. It is a radio galaxy and at 1400

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...

is the fourth-brightest

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmit ...

source in the sky.

Structure and formation

In the late 1970s, François Schweizer studied NGC 1316 extensively and found that the galaxy appeared to look like a small elliptical galaxy with some unusual

dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...

lanes embedded within a much larger envelope of stars. The outer envelope contained many ripples, loops, and arcs. He also identified the presence of a compact disk of gas near the center that appeared inclined relative to the stars and that appeared to rotate faster than the stars (the mass-to-light ratio run in the center of NGC 1316 resembles that of many other giant ellipticals). Based on these results, Schweizer considered that NGC 1316 was built up through the merger of several smaller galaxies. Such merger events may have fueled the central supermassive black hole, that has a mass estimated in 130–150 million of

solar mass The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...

es with gas, causing the galaxy to become a radio galaxy. He also states that NGC 1316 is comparable to the giant elliptical galaxies found in the centers of other

clusters of galaxies The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these obj ...

. Using spectroscopy of its brightest globular clusters, the merger is estimated to have occurred ~3 billion years ago. NGC 1316 spans about 50 000 light-years. It has been proposed too that NGC 1316 may be a galaxy in evolution that eventually will become a Sombrero-like system dominated by a large

bulge __NOTOC__ Bulge may refer to: Astronomy and geography *Bulge (astronomy), a tightly packed group of stars at the center of a spiral galaxy *Equatorial bulge, a bulge around the equator of a planet due to rotation *Tharsis bulge, vast volcanic pla ...

Companions and environment

NGC 1316 is located within the Fornax Cluster, a cluster of galaxies in the constellation Fornax. However, in contrast to Messier 87, which is a similar elliptical galaxy that is located in the center of the Virgo Cluster, NGC 1316 is located at the edge of the Fornax Cluster. NGC 1316 appears to be interacting with NGC 1317, a small spiral galaxy to the north. However, that small spiral galaxy does not appear to be sufficiently large enough to cause the distortions seen in the structure of this galaxy. NGC 1316 has hosted four

supernovae A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when a ...

(all

type Ia 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 ...

): 1980N, 1981D, 2006dd and 2006mr.

Distance estimates

At least two methods have been used to estimate the distance to NGC 1316: surface brightness fluctuation (SBF) in 2003 and planetary nebula luminosity function (PNLF) in 2006. Being a lenticular galaxy, it is not suitable to apply the cepheid variable method. Using SBF, a distance estimate of 20.0 ± 1.6 Mpc was computed. Using PNLF, 45 planetary nebula candidates were located and a distance estimate of 17.9 Mpc was computed. Averaged together, these two distance measurements give a combined distance estimate of 62.0 ± 2.9 Mly (19.0 ± 0.9 Mpc).

Notes

average(20.0 ± 1.6, 17.9 ) = ((20.0 + 17.9) / 2) ± ((1.6² + 0.8²)^0.5 / 2) = 19.0 ± 0.9

Citations

External links

* *
NGC 1316 at ESA/Hubble
{{DEFAULTSORT:NGC 1316 Lenticular galaxies Shell galaxies Fornax Cluster Fornax (constellation)

1316 Year 1316 ( MCCCXVI) was a leap year starting on Thursday (link will display the full calendar) of the Julian calendar. Events January–December * January 28–March 18 – Llywelyn Bren revolts against English rule in Wales. ...

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