NGC 1399

NGC 1399
NGC 1399
	Hubble Space Telescope image of NGC 1399
Observation data (J2000 epoch)
Constellation	Fornax
Right ascension	03h 38.5m
Declination	−35° 27′
Distance	20.23 Mpc (66 Mly)
Apparent magnitude (V)	9.9
Characteristics
Type	E1p
Apparent size (V)	3.2′ × 3.1′
Notable features	Central galaxy of the Fornax cluster
Other designations
	6dFGS gJ033829.0-352702, 2E 816, 2E 0336.5-3536, ESO 358-45, ESO-LV 358-0450, FCC 213, 1H 0335-357, H 0333-35, LEDA 13418, 2MASX J03382908-3527026, MCG-06-09-012, MSH 03-3-03, OHIO E -361, PKS 0336-35, PKS 0336-355 PKS J0338-3523, RBS 454, 1RXS J033828.8-352701, SGC 033634-3536.7, [CAC2009] S0373 b, [CHM2007] HDC 234 J033829.08-3527026, [CHM2007] LDC 249 J033829.08-3527026, [DLB87] F5, [FWB89] Galaxy 100

Last updated September 07, 2024

NGC 1399 is a large elliptical galaxy in the Southern constellation Fornax, the central galaxy in the Fornax Cluster. ^[2] The galaxy is 66 million light-years away from Earth. With a diameter of 130 000 light-years, it is one of the largest galaxies in the Fornax Cluster and slightly larger than the Milky Way. William Herschel discovered this galaxy on October 22, 1835.

Characteristics

It is a type-cD galaxy, with a bright center and a vast, diffuse envelope surrounding it. It is also an early-type galaxy, the largest one in the Fornax Cluster.

Despite their name, early-type galaxies are much older than spiral galaxies, and mostly comprise old, red-colored stars. Very little star formation occurs in these galaxies; the lack of star formation in elliptical galaxies appears to start at the center and then slowly propagates outward.^[3]

Globular clusters

NGC 1399 is very rich in globular clusters. The population is estimated to be between 5700 and 6500. It has been proposed that NGC 1399 has a rich system of globular clusters because NGC 1404 gave up most of its globular clusters due to gravitational interactions. The estimated angular extent, measured from the NGC 1399 centre and up to a limiting radius where the areal density of blue globular clusters falls to 30 per cent of the background level, is 45±5 arcmin, which corresponds to 220–275 kpc at the Fornax distance. The bimodal colour distribution of this globular cluster system, as well as the different radial distribution of blue and red clusters, up to these large distances from the parent galaxy, are confirmed. The azimuthal globular cluster distribution exhibits asymmetries that might be understood in terms of tidal stripping of globulars from NGC 1387, another nearby galaxy. The good agreement between the areal density profile of blue clusters and a projected dark-matter NFW density profile is emphasized.^[4]

Supermassive black hole

The core of NGC 1399 contains a supermassive black hole of 510 million solar masses, a factor of over 2 below the correlation of black hole mass and velocity dispersion. There is also a dramatic signature for central tangential anisotropy. The velocity profiles on adjacent sides 0.5" away from the nucleus show strong bimodality, and the central spectrum shows a large drop in the dispersion. Both of these observations point to an orbital distribution that is tangentially biased. The best-fit orbital model suggests a ratio of the tangential to radial internal velocity dispersions of 3. This ratio is the largest seen in any galaxy to date and will provide an important measure for the mode by which the central black hole has grown.^[5]

Planetary nebulae

There are 37 planetary nebulae in this galaxy. Their magnitudes are around 27. The accuracy of the measured radial velocities of these planetary nebulae is about 70 km/s, which is much smaller than the velocity dispersion of the galaxy.^[6]

Spectrum

A spectrum was taken as part of a study of giant elliptical galaxies to figure out why galaxies of this type do not form stars. The data collected with Herschel showed that, contrary to previous belief, most of these galaxies contain plenty of cold gas – the raw material to form stars – with the exception of NGC 1399 and one other.

A multi-wavelength study suggested that, while hot gas cools down in these galaxies, stars do not form because of feedback from the central supermassive black hole, which heats up the gas again or pushes it beyond the galaxy's reach. For most of the galaxies observed, the activity of the black hole seems to have put an end to star formation but has not yet succeeded in clearing them of all their cold gas, but in the case of NGC 1399 the feedback cycle appears to be at a more advanced stage, as the jets have hardly left any trace of cold gas.^[7]

Ultraluminous X-ray source

In 2010, Chandra X-ray Observatory found an ultraluminous X-ray source (ULX). The ULX's position is in one of NGC 1399's globular clusters, a very old and crowded environment. Evidence from Chandra suggests that a white dwarf star has been torn apart by an intermediate-mass black hole, but this is only a proposal, and its true nature remains a mystery. If confirmed, it would be first black hole found in this setting. A 2019 study of globular cluster ULXs in NGC 1399 ^[8] has since disproven this proposal, as the source has remained X-ray bright far longer than is theoretically possible in the intermediate-mass black hole disrupting a white dwarf scenario.

Environment

NGC 1399 is the central galaxy of the Fornax Cluster, the second richest cluster within 100 megaparsecs. It is also the central galaxy of the main subgroup. Near NGC 1399 are NGC 1396, NGC 1404 and NGC 1387. There are ultracompact dwarf galaxies surrounding the galaxy, while NGC 1427A, an irregular galaxy, lies near its center.

Ultracompact dwarf galaxies were first discovered in the Fornax Cluster in 2003. Almost all of them surround NGC 1399, as it is the central galaxy of the cluster.

Related Research Articles

Fornax is a constellation in the southern celestial hemisphere, partly ringed by the celestial river Eridanus. Its name is Latin for furnace. It was named by French astronomer Nicolas Louis de Lacaille in 1756. Fornax is one of the 88 modern constellations.

An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work The Realm of the Nebulae, along with spiral and lenticular galaxies. Elliptical (E) galaxies are, together with lenticular galaxies (S0) with their large-scale disks, and ES galaxies with their intermediate scale disks, a subset of the "early-type" galaxy population.

Messier 87 is a supergiant elliptical galaxy in the constellation Virgo that contains several trillion stars. One of the largest and most massive galaxies in the local universe, it has a large population of globular clusters—about 15,000 compared with the 150–200 orbiting the Milky Way—and a jet of energetic plasma that originates at the core and extends at least 1,500 parsecs, traveling at a relativistic speed. It is one of the brightest radio sources in the sky and a popular target for both amateur and professional astronomers.

An intermediate-mass black hole (IMBH) is a class of black hole with mass in the range of tens to tens thousand (10²–10⁵) solar masses: significantly higher than stellar black holes but lower than the tens thousand to hundreds trillion (10⁵–10¹⁵) solar mass supermassive black holes. Several IMBH candidate objects have been discovered in the Milky Way galaxy and others nearby, based on indirect gas cloud velocity and accretion disk spectra observations of various evidentiary strength.

The Sombrero Galaxy is a peculiar galaxy of unclear classification in the constellation borders of Virgo and Corvus, being about 9.55 megaparsecs from the Milky Way galaxy. It is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. It has an isophotal diameter of approximately 29.09 to 32.32 kiloparsecs, making it slightly bigger in size than the Milky Way.

Messier 60 or M60, also known as NGC 4649, is an elliptical galaxy approximately 57 million light-years away in the equatorial constellation of Virgo. Together with NGC 4647, it forms a pair known as Arp 116. Messier 60 and nearby elliptical galaxy Messier 59 were discovered by Johann Gottfried Koehler in April 1779, observing a comet in the same part of the sky. Charles Messier added both to his catalogue about three days after this.

<span class="mw-page-title-main">Dwarf galaxy</span> Small galaxy composed of up to several billion stars

A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars. The Large Magellanic Cloud, which closely orbits the Milky Way and contains over 30 billion stars, is sometimes classified as a dwarf galaxy; others consider it a full-fledged galaxy. Dwarf galaxies' formation and activity are thought to be heavily influenced by interactions with larger galaxies. Astronomers identify numerous types of dwarf galaxies, based on their shape and composition.

NGC 1427 is a low-luminosity elliptical galaxy located approximately 71 million light-years away from Earth. It was discovered by John Frederick William Herschel on November 28, 1837. It is a member of the Fornax Cluster. The galaxy has a stellar mass of 7.9 × 10¹⁰M_☉, and a total mass of 9.4 × 10¹⁰M_☉. However, the mass of the dark matter halo surrounding the galaxy is around 4.3 × 10¹²M_☉.

NGC 4889 is an E4 supergiant elliptical galaxy. It was discovered in 1785 by the British astronomer Frederick William Herschel I, who catalogued it as a bright, nebulous patch. The brightest galaxy within the northern Coma Cluster, it is located at a median distance of 94 million parsecs from Earth. At the core of the galaxy is a supermassive black hole that heats the intracluster medium through the action of friction from infalling gases and dust. The gamma ray bursts from the galaxy extend out to several million light years of the cluster.

NGC 3377 is an elliptical galaxy in the constellation Leo. It is a member of the M96 Group and is about 26 Mly away, with a diameter of approximately 40 000 ly. The supermassive black hole at the core of NGC 3377 has a mass of 8.0+0.5
−0.6×10⁷ M_☉. A very faint companion galaxy, NGC 3377A is 7.1' NW.

NGC 1407 is an elliptical galaxy in Eridanus. It is at a distance of 76 million light-years from Earth. It is the brightest galaxy in the NGC 1407 Group, part of the Eridanus Group, with NGC 1407 being its brightest member. NGC 1400, the second-brightest of the group lies 11.8 arcmin away.

NGC 3311 is a super-giant elliptical galaxy located about 190 million light-years away in the constellation Hydra. The galaxy was discovered by astronomer John Herschel on March 30, 1835. NGC 3311 is the brightest member of the Hydra Cluster and forms a pair with NGC 3309 which along with NGC 3311, dominate the central region of the Hydra Cluster.

NGC 3923 is an elliptical galaxy located in the constellation Hydra. It is located at a distance of circa 90 million light years from Earth, which, given its apparent dimensions, means that NGC 3923 is about 155,000 light years across. NGC 3923 is an example of a shell galaxy where the stars in its halo are arranged in layers. It has more than twenty shells. It was discovered by William Herschel on March 7, 1791.

NGC 720 is an elliptical galaxy located in the constellation Cetus. It is located at a distance of circa 80 million light years from Earth, which, given its apparent dimensions, means that NGC 720 is about 110,000 light years across. It was discovered by William Herschel on October 3, 1785. The galaxy is included in the Herschel 400 Catalogue. It lies about three and a half degrees south and slightly east from zeta Ceti.

<span class="mw-page-title-main">NGC 1380</span> Galaxy in the constellation Fornax

NGC 1380 is a lenticular galaxy located in the constellation Fornax. It is located at a distance of circa 60 million light years from Earth, which, given its apparent dimensions, means that NGC 1380 is about 85,000 light years across. It was discovered by James Dunlop on September 2, 1826. It is a member of the Fornax Cluster.

NGC 4636 is an elliptical galaxy located in the constellation Virgo. It is a member of the NGC 4753 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. It is located at a distance of about 55 million light years from Earth, which, given its apparent dimensions, means that NGC 4636 is about 105,000 light years across.

NGC 5846 is an elliptical galaxy located in the constellation Virgo. It is located at a distance of circa 90 million light years from Earth, which, given its apparent dimensions, means that NGC 5846 is about 110,000 light years across. It was discovered by William Herschel on February 24, 1786. It lies near 110 Virginis and is part of the Herschel 400 Catalogue. It is a member of the NGC 5846 Group of galaxies, itself one of the Virgo III Groups strung out to the east of the Virgo Supercluster of galaxies.

NGC 1460 is a barred lenticular galaxy with a peanut-shaped bar approximately 65 million light-years away from Earth in the constellation of Eridanus. It was discovered by astronomer John Herschel on November 28, 1837. It is a member of the Fornax cluster.

NGC 1373 is a dwarf elliptical galaxy located 61 millon light years away in constellation of Fornax. The galaxy was discovered by astronomer John Herschel on November 29, 1837, and is a member of the Fornax Cluster. NGC 1373 is a host to a supermassive black hole with an estimated mass of 4.6 millon solar masses.

NGC 1419 is an elliptical galaxy located 62 millon light years away in the constellation of Eridanus. The galaxy was discovered by astronomer John Herschel on October 22, 1835, and is a member of the Fornax Cluster. NGC 1419 is a host to a supermassive black hole with an estimated mass of 25 millon solar masses.

References

1 2 3 4 5 Dunlop, Storm (2005). Atlas of the Night Sky. Collins. ISBN 978-0-00-717223-8.
↑ "Multiwavelength Atlas of Galaxies - NGC 1399" . Retrieved 2011-06-18.
↑ Howell, Elizabeth (2015). "Colossal Ancient Galaxies Die from the Inside Out". space.com. Retrieved 5 March 2017.
↑ Bassino, L. P.; Faifer, F. R.; Forte, J. C.; Dirsch, B.; Richtler, T.; Geisler, D.; Schuberth, Y. (2006). "Large-scale study of the NGC 1399 globular cluster system in Fornax". Astronomy & Astrophysics. 451 (3): 789–796. arXiv: astro-ph/0603349 . Bibcode:2006A&A...451..789B. doi:10.1051/0004-6361:20054563. S2CID 15549056.
↑ GEBHARDT, K.; LAUER, T. R.; PINKNEY, J.; BENDER, R.; RICHSTONE, D.; ALLER, M.; BOWER, G.; DRESSLER, A. (December 2007). "The Black Hole Mass and Extreme Orbital Structure in NGC 1399". The Astrophysical Journal. 671 (2): 1321–1328. arXiv: 0709.0585 . Bibcode:2007ApJ...671.1321G. doi:10.1086/522938. hdl:2152/35191. S2CID 12042010.
↑ "Planetary nebulae in NGC 1399". European Southern Observatory. Retrieved 28 July 2019.
↑ "ESA Science & Technology - Herschel spectrum of the elliptical galaxy NGC 1399".
↑ Dage, Kristen C.; Zepf, Stephen E.; Peacock, Mark B.; Bahramian, Arash; Noroozi, Omid; Kundu, Arunav; MacCarone, Thomas J. (2019). "X-ray spectral variability of ultraluminous X-ray sources in extragalactic globular clusters". Monthly Notices of the Royal Astronomical Society. 485 (2): 1694. arXiv: 1902.05073 . Bibcode:2019MNRAS.485.1694D. doi: 10.1093/mnras/stz479 .

External links

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[nightsky-1] 1 2 3 4 5 Dunlop, Storm (2005). Atlas of the Night Sky. Collins. ISBN 978-0-00-717223-8.

[forn1-2] "Multiwavelength Atlas of Galaxies - NGC 1399" . Retrieved 2011-06-18.

[3] Howell, Elizabeth (2015). "Colossal Ancient Galaxies Die from the Inside Out". space.com. Retrieved 5 March 2017.

[4] Bassino, L. P.; Faifer, F. R.; Forte, J. C.; Dirsch, B.; Richtler, T.; Geisler, D.; Schuberth, Y. (2006). "Large-scale study of the NGC 1399 globular cluster system in Fornax". Astronomy & Astrophysics. 451 (3): 789–796. arXiv: astro-ph/0603349 . Bibcode:2006A&A...451..789B. doi:10.1051/0004-6361:20054563. S2CID 15549056.

[Gebhardt2007-5] GEBHARDT, K.; LAUER, T. R.; PINKNEY, J.; BENDER, R.; RICHSTONE, D.; ALLER, M.; BOWER, G.; DRESSLER, A. (December 2007). "The Black Hole Mass and Extreme Orbital Structure in NGC 1399". The Astrophysical Journal. 671 (2): 1321–1328. arXiv: 0709.0585 . Bibcode:2007ApJ...671.1321G. doi:10.1086/522938. hdl:2152/35191. S2CID 12042010.

[6] "Planetary nebulae in NGC 1399". European Southern Observatory. Retrieved 28 July 2019.

[7] "ESA Science & Technology - Herschel spectrum of the elliptical galaxy NGC 1399".

[8] Dage, Kristen C.; Zepf, Stephen E.; Peacock, Mark B.; Bahramian, Arash; Noroozi, Omid; Kundu, Arunav; MacCarone, Thomas J. (2019). "X-ray spectral variability of ultraluminous X-ray sources in extragalactic globular clusters". Monthly Notices of the Royal Astronomical Society. 485 (2): 1694. arXiv: 1902.05073 . Bibcode:2019MNRAS.485.1694D. doi: 10.1093/mnras/stz479 .

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