NGC 1275 (also known as Perseus A or Caldwell 24) is a type 1.5

Seyfert galaxy Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra ...

located around 237 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 direction of the constellation

Perseus In Greek mythology, Perseus (Help:IPA/English, /ˈpɜːrsiəs, -sjuːs/; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of Mycenae and of the Perseid dynasty. He was, alongside Cadmus ...

. NGC 1275 corresponds to the

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 ...

Perseus A and is situated near the center of the large

Perseus Cluster The Perseus cluster (Abell 426) is a cluster of galaxies in the constellation Perseus. It has a recession speed of 5,366 km/ s and a diameter of 863′. It is one of the most massive objects in the known universe, containing thousands o ...

of galaxies.

Properties

NGC 1275 consists of two galaxies, a central

type-cD galaxy The type-cD galaxy (also cD-type galaxy, cD galaxy) is a galaxy morphology classification, a subtype of type-D giant elliptical galaxy. Characterized by a large halo of stars, they can be found near the centres of some rich galaxy clusters. ...

in the

, and a so-called "high velocity system" (HVS) which lies in front of it. The HVS is moving at 3000 km/s towards the dominant system, and is believed to be merging with the

. The HVS is not affecting the cD galaxy as it lies at least 200 thousand light years from it. However

tidal interactions The tidal force is a gravitational effect that stretches a body along the line towards the center of mass of another body due to a gradient (difference in strength) in gravitational field from the other body; it is responsible for diverse phenom ...

are disrupting it and

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 ...

produced by its interaction with the

intracluster medium In astronomy, the intracluster medium (ICM) is the superheated plasma that permeates a galaxy cluster. The gas consists mainly of ionized hydrogen and helium and accounts for most of the baryonic material in galaxy clusters. The ICM is heated to t ...

of Perseus is stripping its gas as well as producing large amounts of star formation within it Dazzling Galaxy

The central cluster galaxy contains a massive network of

spectral line A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ...

emitting filaments, which apparently are being dragged out by rising bubbles of relativistic plasma generated by the central

active galactic nucleus An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not pro ...

. Long gaseous filaments made up of threads of gas stretch out beyond the galaxy, into the multimillion-degree, X-ray–emitting gas that fills the cluster. The amount of gas contained in a typical thread is approximately one million times the mass of the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared rad ...

. They are only 200 light-years wide, are often very straight, and extend for up to 20,000 light-years. The existence of the filaments poses a problem. As they are much cooler than the surrounding intergalactic cloud, it is unclear how they have existed for such a long time, or why they have not warmed, dissipated or collapsed to form stars. One possibility is that weak magnetic fields (about one-ten-thousandth the strength of Earth's field) exert enough force on the

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s within the threads to keep them together. NGC 1275 contains 13 billion

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 o ...

es of

molecular hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, ...

that seems to be infalling from Perseus'

in a

cooling flow A cooling flow occurs according to the theory that the intracluster medium (ICM) in the centres of galaxy clusters should be rapidly cooling at the rate of tens to thousands of solar masses per year. This should happen as the ICM (a plasma) is quic ...

, both feeding its active nucleus and fueling significant amounts of

star formation Star formation is the process by which dense regions within molecular clouds in interstellar space, sometimes referred to as "stellar nurseries" or "star-forming regions", collapse and form stars. As a branch of astronomy, star formation includ ...

The presence of an active nucleus demonstrates that 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 ...

is present in NGC 1275's center. The black hole is surrounded by a rotating disk of molecular gas. High-resolution observations of the rotation of this disk obtained using

adaptive optics Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of incoming wavefront distortions by deforming a mirror in order to compensate for the distortion. It is used in astronomical tel ...

at the

Gemini North The Gemini Observatory is an astronomical observatory consisting of two 8.1-metre (26.6 ft) telescopes, Gemini North and Gemini South, which are located at two separate sites in Hawaii and Chile, respectively. The twin Gemini telescopes prov ...

telescope indicate a central mass of approximately 800 million

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 o ...

es, including both the mass of the black hole and of the inner core of the gas disk. Two supernovae have been observed in NGC 1275: SN 1968A (type unknown, mag. 15.5), and SN 2005mz ( type Ia, mag. 18.2).Transient Name Server entry for SN 2005mz.
Retrieved 29 March 2023.

References

External links

*

– NASA image & description

– NASA image showing unusual gas filaments * Fabian, A.C., et al
"A deep Chandra observation of the Perseus cluster: shocks and ripples"
''Monthly Notices of the Royal Astronomical Society''. Vol. 344 (2003): L43 (arXiv:astro-ph/0306036v2). * Fabian, A.C.

', 968–970. * Gabany, R. Jay

– An image made with a 20" telescope, which displays the unusual gas filaments {{DEFAULTSORT:NGC 1275 Peculiar galaxies Interacting galaxies Seyfert galaxies Starburst galaxies Radio galaxies Luminous infrared galaxies Perseus (constellation)

1275 Year 1275 ( MCCLXXV) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire * Battle of Neopatras: Emperor Michael VIII (Palaiologos) assembles a Byzanti ...

02669 012429 84 Perseus Cluster 024b