Centaurus A

Last updated
Centaurus A
ESO Centaurus A LABOCA.jpg
Centaurus A (NGC 5128)
Observation data (J2000 epoch)
Constellation Centaurus
Right ascension 13h 25m 27.6s [1]
Declination −43° 01′ 09″ [1]
Redshift 547 ± 5 km/s [1]
Distance 11–13 Mly (3–5 Mpc) [2] [3] [4] [5] [6]
Apparent magnitude  (V)6.84 [7] [8]
Characteristics
Type S0 pec [1] or Ep [9]
Size60,000 ly [10]
Apparent size  (V)25'.7 × 20'.0 [1]
Notable featuresClosest radio galaxy; closest BL Lacertae object; unusual dust lane
Other designations
NGC 5128, [1] Arp 153, [1] PGC 46957, [1] 4U 1322–42, [11] Caldwell 77

Centaurus A (also known as NGC 5128 or Caldwell 77) is a galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop from his home in Parramatta, in New South Wales, Australia. There is considerable debate in the literature regarding the galaxy's fundamental properties such as its Hubble type (lenticular galaxy or a giant elliptical galaxy) [9] and distance (11–13 million light-years). [2] [3] [4] [5] [6] It is the closest radio galaxy to Earth, as well as the closest BL Lac object, [12] so its active galactic nucleus has been extensively studied by professional astronomers. [13] The galaxy is also the fifth-brightest in the sky, [13] making it an ideal amateur astronomy target. [14] It is only visible from the southern hemisphere and low northern latitudes.

Contents

The center of the galaxy contains a supermassive black hole with a mass of 55 million solar masses, [15] which ejects a relativistic jet that is responsible for emissions in the X-ray and radio wavelengths. By taking radio observations of the jet separated by a decade, astronomers have determined that the inner parts of the jet are moving at about half of the speed of light. X-rays are produced farther out as the jet collides with surrounding gases, resulting in the creation of highly energetic particles. The X-ray jets of Centaurus A are thousands of light-years long, while the radio jets are over a million light-years long. [16]

It is also one of the nearest large starburst galaxies, of which a galactic collision is suspected to be responsible for an intense burst of star formation. Models have suggested that Centaurus A was a large elliptical galaxy that collided with a smaller spiral galaxy, with which it will eventually merge. [17] For that reason, the galaxy has been of particular interest to astronomers for years. While collisions of spiral galaxies are relatively common, the effects of a collision between an elliptical and a spiral galaxy are not fully understood. [18]

Observational history

NGC 5128 was discovered on 29 April 1826 by James Dunlop during a survey at the Parramatta Observatory. [19] [20]

In 1847 John Herschel described the galaxy as "two semi-ovals of elliptically formed nebula appearing to be cut asunder and separated by a broad obscure band parallel to the larger axis of the nebula, in the midst of which a faint streak of light parallel to the sides of the cut appears." [21]

In 1949 John Gatenby Bolton, Bruce Slee and Gordon Stanley localized NGC 5128 as one of the first extragalactic radio sources. [22] Five years later, Walter Baade and Rudolph Minkowski suggested that the peculiar structure is the result of a merge event of a giant elliptical galaxy and a small spiral galaxy. [23] The first detection of X-ray emissions, using a sounding rocket, was performed in 1970. [24] In 1975–76 gamma-ray emissions from Centaurus A were observed through the atmospheric Cherenkov technique. [25]

The Einstein Observatory detected an X-ray jet emanating from the nucleus in 1979. [26] Ten years later, young blue stars were found along the central dust band with the Hubble Space Telescope. [27]

The Chandra X-ray Observatory identified in 1999 more than 200 new point sources. [28] Another space telescope, the Spitzer Space Telescope, found a parallelogram-shaped structure of dust in near infrared images of Centaurus A in 2006. [29]

Evidence of gamma emissions with very high energy (more than 100 GeV) was detected by the H.E.S.S-Observatorium in Namibia in 2009. [30]

The following year, Centaurus A was identified as a source of cosmic rays of highest energies, after years of observations by Pierre Auger Observatory. [31] In 2016 a review of data from Chandra and XMM-Newton, unusual high flares of energy were found in NGC 5128 and the galaxy NGC 4636. Jimmy Irwin of University of Alabama hypothesized the discovery as potentially a black hole in a yet unknown process or an intermediate-mass black hole.[ citation needed ]

Morphology

Centaurus A may be described as having a peculiar morphology. As seen from Earth, the galaxy looks like a lenticular or elliptical galaxy with a superimposed dust lane. [32] The peculiarity of this galaxy was first identified in 1847 by John Herschel, and the galaxy was included in Halton Arp's Atlas of Peculiar Galaxies (published in 1966) as one of the best examples of a "disturbed" galaxy with dust absorption. [33] The galaxy's strange morphology is generally recognized as the result of a merger between two smaller galaxies. [34]

Zoom movie of the galaxy Centaurus A, showing different aspects of the galaxy in several wavelengths.
Schematic diagram of the components of the Centaurus A galaxy StuctureCenA-EN.png
Schematic diagram of the components of the Centaurus A galaxy

The bulge of this galaxy is composed mainly of evolved red stars. [32] The dusty disk, however, has been the site of more recent star formation; [13] over 100 star formation regions have been identified in the disk. [35]

Supernovae

Two supernovae have been detected in Centaurus A. [36] The first supernova, named SN 1986G, was discovered within the dark dust lane of the galaxy by R. Evans in 1986. [37] It was later identified as a Type Ia supernova, [38] which forms when a white dwarf's mass grows large enough to ignite carbon fusion in its center, touching off a runaway thermonuclear reaction, as may happen when a white dwarf in a binary star system strips gas away from the other star. SN 1986G was used to demonstrate that the spectra of type Ia supernovae are not all identical, and that type Ia supernovae may differ in the way that they change in brightness over time. [38]

The second supernova, designated SN 2016adj, [39] was discovered by Backyard Observatory Supernova Search in February 2016 and was initially classified as a Type II supernova based on its H-alpha emission line. [40] [41] A subsequent classification found the spectrum best resembled the Type Ib core-collapse supernova 1999dn. [42] (See Type Ib and Ic supernovae).

In addition to these supernovae, a luminous red nova, designated AT 2020nqq (type ILRT, mag. 17.8), was discovered on 27 June 2020. [43]

Distance

Distance estimates to Centaurus A established since the 1980s typically range between 3–5 Mpc. [2] [3] [4] [5] [6] [44] Classical Cepheids discovered in the heavily obscured dust lane of Centaurus A yield a distance between ~3–3.5 Mpc, depending on the nature of the extinction law adopted and other considerations. [4] [5] Mira variables [44] and Type II Cepheids [4] [5] were also discovered in Centaurus A, the latter being rarely detected beyond the Local Group. [45] The distance to Centaurus A established from several indicators such as Mira variables and planetary nebulae favour a more distant value of ~3.8 Mpc. [9] [6]

Nearby galaxies and galaxy group information

Centaurus A is at the center of one of two subgroups within the Centaurus A/M83 Group, a nearby group of galaxies. [46] Messier 83 (the Southern Pinwheel Galaxy) is at the center of the other subgroup. These two groups are sometimes identified as one group [47] [48] and sometimes identified as two groups. [49] However, the galaxies around Centaurus A and the galaxies around M83 are physically close to each other, and both subgroups appear not to be moving relative to each other. [50] The Centaurus A/M83 Group is located in the Virgo Supercluster.[ citation needed ]

In addition to dwarf galaxies, Centaurus A, like most galaxies, has a population of globular clusters. Some objects that appear to be globular clusters are hypothesized to be the tidally stripped cores of former galaxies. The most extreme example is the object VHH81-01, whose central black hole is estimated to be around 8×105 M☉. [51]

Observations

Radio waves

RadioCenA-EN.png
Overview over the radio structure of Centaurus A. The whole radio emitting region extends about 1.8 million light years (about 8° degrees in the sky). Through observations with the VLBI technique structures of the jet and the core smaller than a light year could be resolved (corresponding to a resolution of 0.68 x 0.41 milli-arcseconds. [52] )
This view of the jets of Centaurus A was created through observations in radio waves with a wavelength of 20 cm with the VLA. The position of the radio jet and the knots within the jets matches very well with the structures seen in the x-ray jet. This region of the jet is named ,,Inner Lobe". CentaurusA VR37 hi.tif
This view of the jets of Centaurus A was created through observations in radio waves with a wavelength of 20 cm with the VLA. The position of the radio jet and the knots within the jets matches very well with the structures seen in the x-ray jet. This region of the jet is named „Inner Lobe“.

In July 2021 the Event Horizon Telescope released a resolved image of Centaurus A showing the jet coming from the black hole at its center.

Visibility

Centaurus A is located approximately 4° north of Omega Centauri (a globular cluster visible with the naked eye). [14] Because the galaxy has a high surface brightness and relatively large angular size, it is an ideal target for amateur astronomy observations. The bright central bulge and dark dust lane are visible even in finderscopes and large binoculars, [14] and additional structure may be seen in larger telescopes. [14] Claims have been made that Centaurus A is visible to the naked eye under exceptionally good conditions. [54]

See also

Related Research Articles

<span class="mw-page-title-main">Seyfert galaxy</span> Class of active galaxies with very bright nuclei

Seyfert galaxies are one of the two largest groups of active galaxies, along with quasar host galaxies. They have quasar-like nuclei with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.

<span class="mw-page-title-main">Pinwheel Galaxy</span> Galaxy in the constellation Ursa Major

The Pinwheel Galaxy is a face-on, unbarred, and counterclockwise spiral galaxy located 21 million light-years from Earth in the constellation Ursa Major. It was discovered by Pierre Méchain in 1781 and was communicated that year to Charles Messier, who verified its position for inclusion in the Messier Catalogue as one of its final entries.

<span class="mw-page-title-main">Messier 83</span> Barred spiral galaxy in the constellation Hydra

Messier 83 or M83, also known as the Southern Pinwheel Galaxy and NGC 5236, is a barred spiral galaxy approximately 15 million light-years away in the constellation borders of Hydra and Centaurus. Nicolas-Louis de Lacaille discovered M83 on 17 February 1752 at the Cape of Good Hope. Charles Messier added it to his catalogue of nebulous objects in March 1781.

NGC 4631 is a barred spiral galaxy in the constellation Canes Venatici about 30 million light years away from Earth. It was discovered on 20 March 1787 by German-British astronomer William Herschel. This galaxy's slightly distorted wedge shape gives it the appearance of a herring or a whale, hence its nickname. Because this nearby galaxy is seen edge-on from Earth, professional astronomers observe this galaxy to better understand the gas and stars located outside the plane of the galaxy.

<span class="mw-page-title-main">Whirlpool Galaxy</span> Galaxy in the constellation Canes Venatici

The Whirlpool Galaxy, also known as Messier 51a (M51a) or NGC 5194, is an interacting grand-design spiral galaxy with a Seyfert 2 active galactic nucleus. It lies in the constellation Canes Venatici, and was the first galaxy to be classified as a spiral galaxy. It is 7.22 megaparsecs away and 23.58 kiloparsecs (76,900 ly) in diameter.

<span class="mw-page-title-main">Messier 84</span> Galaxy in the constellation Virgo

Messier 84 or M84, also known as NGC 4374, is a giant elliptical or lenticular galaxy in the constellation Virgo. Charles Messier discovered the object in 1781 in a systematic search for "nebulous objects" in the night sky. It is the 84th object in the Messier Catalogue and in the heavily populated core of the Virgo Cluster of galaxies, part of the local supercluster.

<span class="mw-page-title-main">Centaurus A/M83 Group</span> Group of galaxies in the constellations Centaurus, Hydra and Virgo

The Centaurus A/M83 Group is a complex group of galaxies in the constellations Hydra, Centaurus, and Virgo. The group may be roughly divided into two subgroups. The Cen A Subgroup, at a distance of 11.9 Mly, is centered on Centaurus A, a nearby radio galaxy. The M83 Subgroup, at a distance of 14.9 Mly, is centered on the Messier 83 (M83), a face-on spiral galaxy.

<span class="mw-page-title-main">Messier 108</span> Galaxy in the constellation Ursa Major

Messier 108 is a barred spiral galaxy about 28 million light-years away from Earth in the northern constellation Ursa Major. It was discovered by Pierre Méchain in 1781 or 1782. From the Earth, this galaxy is seen almost edge-on.

<span class="mw-page-title-main">NGC 6946</span> Galaxy in the constellations Cepheus & Cygnus

NGC 6946, sometimes referred to as the Fireworks Galaxy, is a face-on intermediate spiral galaxy with a small bright nucleus, whose location in the sky straddles the boundary between the northern constellations of Cepheus and Cygnus. Its distance from Earth is about 25.2 million light-years or 7.72 megaparsecs, similar to the distance of M101 in the constellation Ursa Major. Both were once considered to be part of the Local Group, but are now known to be among the dozen bright spiral galaxies near the Milky Way but beyond the confines of the Local Group. NGC 6946 lies within the Virgo Supercluster.

<span class="mw-page-title-main">NGC 891</span> Galaxy in the constellation Andromeda

NGC 891 is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. The galaxy is a member of the NGC 1023 group of galaxies in the Local Supercluster. It has an H II nucleus.

<span class="mw-page-title-main">NGC 1275</span> Seyfert galaxy in the constellation Perseus

NGC 1275 is a type 1.5 Seyfert galaxy located around 237 million light-years away in the direction of the constellation Perseus. NGC 1275 is a member of the large Perseus Cluster of galaxies.

<span class="mw-page-title-main">NGC 4725</span> Galaxy in the constellation Coma Berenices

NGC 4725 is an intermediate barred spiral galaxy with a prominent ring structure, located in the northern constellation of Coma Berenices near the north galactic pole. It was discovered by German-born British astronomer William Herschel on April 6, 1785. The galaxy lies at a distance of approximately 40 megalight-years from the Milky Way. NGC 4725 is the brightest member of the Coma I Group of the Coma-Sculptor Cloud, although it is relatively isolated from the other members of this group. This galaxy is strongly disturbed and is interacting with neighboring spiral galaxy NGC 4747, with its spiral arms showing indications of warping. The pair have an angular separation of 24′, which corresponds to a projected linear separation of 370 kly. A tidal plume extends from NGC 4747 toward NGC 4725.

<span class="mw-page-title-main">NGC 1316</span> Lenticular radio galaxy in the constellation Fornax

NGC 1316 is a lenticular galaxy about 60 million light-years away in the constellation Fornax. It is a radio galaxy and at 1400 MHz is the fourth-brightest radio source in the sky.

<span class="mw-page-title-main">NGC 3169</span> Galaxy in the constellation Sextans

NGC 3169 is a spiral galaxy about 75 million light years away in the constellation Sextans. It has the morphological classification SA(s)a pec, which indicates this is a pure, unbarred spiral galaxy with tightly-wound arms and peculiar features. There is an asymmetrical spiral arm and an extended halo around the galaxy. It is a member of the NGC 3166 Group of galaxies, which is a member of the Leo II Groups, a series of galaxies and galaxy clusters strung out from the right edge of the Virgo Supercluster.

<span class="mw-page-title-main">NGC 613</span> Galaxy in the constellation of Sculptor

NGC 613 is a barred spiral galaxy located 67 million light years away in the southern constellation of Sculptor. This galaxy was discovered in 1798 by German-English astronomer William Herschel, then re-discovered and catalogued by Scottish astronomer James Dunlop. It was first photographed in 1912, which revealed the spiral form of the nebula. During the twentieth century, radio telescope observations showed that a linear feature in the nucleus was a relatively strong source of radio emission.

<span class="mw-page-title-main">NGC 3862</span> Galaxy in the constellation Leo

NGC 3862 is an elliptical galaxy located 300 million light-years away in the constellation Leo. Discovered by astronomer William Herschel on April 27, 1785, NGC 3862 is an outlying member of the Leo Cluster.

<span class="mw-page-title-main">NGC 5643</span> Galaxy in the constellation Lupus

NGC 5643 is an intermediate spiral galaxy in the constellation Lupus. Based on the tip of the red-giant branch distance indicator, it is located at a distance of about 40 million light-years. NGC 5643 has an active galactic nucleus and is a type II Seyfert galaxy.

<span class="mw-page-title-main">NGC 7469</span> Galaxy located in the constellation Pegasus

NGC 7469 is an intermediate spiral galaxy in the constellation of Pegasus. NGC 7469 is located about 200 million light-years away from Earth, which means, given its apparent dimensions, that NGC 7469 is approximately 90,000 light-years across. It was discovered by William Herschel on November 12, 1784.

<span class="mw-page-title-main">NGC 4636</span> Galaxy in the constellation Virgo

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.

<span class="mw-page-title-main">NGC 877</span> Galaxy located in the constellation Aries

NGC 877 is an intermediate spiral galaxy located in the constellation Aries. It is located at a distance of circa 160 million light years from Earth, which, given its apparent dimensions, means that NGC 877 is about 115,000 light years across. It was discovered by William Herschel on October 14, 1784. It interacts with NGC 876.

References

  1. 1 2 3 4 5 6 7 8 "NASA/IPAC Extragalactic Database". Results for Centaurus A. Retrieved 6 December 2006.
  2. 1 2 3 J. L. Tonry; A. Dressler; J. P. Blakeslee; E. A. Ajhar; et al. (2001). "The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances". Astrophysical Journal. 546 (2): 681–693. arXiv: astro-ph/0011223 . Bibcode:2001ApJ...546..681T. doi:10.1086/318301. S2CID   17628238.
  3. 1 2 3 "Distance Results for NGC 5128". NASA/IPAC Extragalactic Database. Retrieved 26 April 2010.
  4. 1 2 3 4 5 Ferrarese Laura; Mould Jeremy R.; Stetson Peter B.; Tonry John L.; et al. (2007). "The Discovery of Cepheids and a Distance to NGC 5128". Astrophysical Journal. 654 (1): 186–218. arXiv: astro-ph/0605707 . Bibcode:2007ApJ...654..186F. doi:10.1086/506612. S2CID   17895798.
  5. 1 2 3 4 5 Majaess, D. (2010). "The Cepheids of Centaurus A (NGC 5128) and Implications for H0". Acta Astronomica. 60 (2): 121. arXiv: 1006.2458 . Bibcode:2010AcA....60..121M.
  6. 1 2 3 4 Harris, Gretchen L. H.; Rejkuba, Marina; Harris, William E. (2010). "The Distance to NGC 5128 (Centaurus A)". Publications of the Astronomical Society of Australia. 27 (4): 457–462. arXiv: 0911.3180 . Bibcode:2010PASA...27..457H. doi:10.1071/AS09061. S2CID   16912328.
  7. ↑ "NAME Centaurus A". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 29 November 2009.
  8. ↑ Armando, Gil de Paz; Boissier; Madore; Seibert; Boselli; et al. (2007). "The GALEX Ultraviolet Atlas of Nearby Galaxies". Astrophysical Journal Supplement. 173 (2): 185–255. arXiv: astro-ph/0606440 . Bibcode:2007ApJS..173..185G. doi:10.1086/516636. S2CID   119085482.
  9. 1 2 3 Harris, Gretchen L. H. (2010). "NGC 5128: The Giant Beneath". Publications of the Astronomical Society of Australia. 27 (4): 475–481. arXiv: 1004.4907 . Bibcode:2010PASA...27..475H. doi:10.1071/AS09063. S2CID   118604663.
  10. ↑ "APOD: 2012 April 4 – Centaurus A". apod.nasa.gov. Archived from the original on 3 October 2014.
  11. ↑ "UHURU4 – Uhuru Fourth (4U) Catalog". heasarc.gsfc.nasa.gov.
  12. ↑ Chiaberge, M.; Capetti, A.; Celotti, A. (2001). "The BL Lac heart of Centaurus A". Monthly Notices of the Royal Astronomical Society. 324 (4): L33–L37. arXiv: astro-ph/0105159 . Bibcode:2001MNRAS.324L..33C. doi: 10.1046/j.1365-8711.2001.04642.x .
  13. 1 2 3 F. P. Israel (1998). "Centaurus A – NGC 5128". Astronomy and Astrophysics Review. 8 (4): 237–278. arXiv: astro-ph/9811051 . Bibcode:1998A&ARv...8..237I. doi:10.1007/s001590050011. S2CID   18353347.
  14. 1 2 3 4 D. J. Eicher (1988). The Universe from Your Backyard . Cambridge: Cambridge University Press. ISBN   978-0-521-36299-3.
  15. ↑ "Radio Telescopes Capture Best-Ever Snapshot of Black Hole Jets". NASA. 20 May 2011. Retrieved 2 October 2012.
  16. ↑ Nemiroff, R.; Bonnell, J., eds. (13 April 2011). "Centaurus Radio Jets Rising". Astronomy Picture of the Day . NASA . Retrieved 16 April 2011.
  17. ↑ Quillen, A. C.; Brookes, M. H.; Keene, J.; Stern, D.; Lawrence, C. R.; Werner, M. W. (2006). "Spitzer Observations of the Dusty Warped Disk of Centaurus A". Astrophysical Journal. 645 (2): 1092–1101. arXiv: astro-ph/0601135 . Bibcode:2006ApJ...645.1092Q. doi:10.1086/504418. S2CID   18443587.
  18. ↑ "Radio galaxy Centaurus A". European Southern Observatory (ESO). 8 February 2000.
  19. ↑ Robertson, Peter; Cozens, Glen; Orchiston, Wayne; Slee, Bruce; Wendt, Harry (2010). "Early Australian Optical and Radio Observations of Centaurus A". Publications of the Astronomical Society of Australia. 27 (4): 402–430. arXiv: 1012.5137 . Bibcode:2010PASA...27..402R. doi:10.1071/AS09071. ISSN   1323-3580. S2CID   54580482.
  20. ↑ Dunlop, James (31 December 1828). "A catalogue of nebulæ and clusters of stars in the southern hemisphere, observed at Paramatta in New South Wales, …". Philosophical Transactions of the Royal Society of London. 118: 113–151. doi: 10.1098/rstl.1828.0010 . ISSN   0261-0523. Centaurus A is listed on p. 138 as entry number 482. A sketch of Centaurus A appears as Fig. 20 on the plate between pages 114 and 115.
  21. ↑ Herschel, John F. W. (1878). Outlines of astronomy (1 ed.). London Longmans, Green. p. 602. doi:10.1017/cbo9780511709111. ISBN   978-1-108-01377-2.
  22. ↑ J. G. Bolton; G. J. Stanley; O. B. Slee (1949). "Positions of Three Discrete Sources of Galactic Radio-Frequency Radiation". Nature. 164 (4159): 101–102. Bibcode:1949Natur.164..101B. doi:10.1038/164101b0. S2CID   4073162.
  23. ↑ Baade, W.; Minkowski, R. (1 January 1954). "On the Identification of Radio Sources". Astrophysical Journal. 119: 215. Bibcode:1954ApJ...119..215B. doi:10.1086/145813 – via NASA ADS.
  24. ↑ C. S. Bowyer; M. Lampton; J. Mack; F. de Mendonca (1970). "Detection of X-Ray Emission from 3C 273 and NGC 5128". Astrophysical Journal. 161: L1. Bibcode:1970ApJ...161L...1B. doi:10.1086/180559.
  25. ↑ Grindlay, J. E.; Helmken, H. F.; Brown, R. H.; Davis, J.; Allen, L. R. (1 April 1975). "Evidence for the detection of gamma rays from Centaurus A at gamma-ray energies above 300 GeV". Astrophysical Journal Letters. 197: L9–L12NASA ADS. Bibcode:1975ApJ...197L...9G. doi:10.1086/181764.
  26. ↑ E. J. Schreier; E. Feigelson; J. Delvaille; R. Giacconi; D. A. Schwartz (1979). "EINSTEIN Observations of The X-Ray Structure of Centaurus A: Evidence For The Radio-Lobe Energy Source". Astrophysical Journal, Part 2. 234: 39–43. Bibcode:1979ApJ...234L..39S. doi: 10.1086/183105 .
  27. ↑ "HubbleSite – NewsCenter – Hubble Provides Multiple Views of How to Feed a Black Hole (05/14/1998) – Background Info". Archived from the original on 30 October 2007. Retrieved 14 October 2015.
  28. ↑ R. P. Kraft; J. M. Kregenow; W. R. Forman; C. Jones; S. S. Murray (20 October 2001). "Chandra Observations of the X-Ray Point Source Population in Centaurus A". Astrophysical Journal. 560 (2): 675–688. Bibcode:2001ApJ...560..675K. doi:10.1086/323056.
  29. ↑ Alice C. Quillen; Mairi H. Brookes; Jocelyn Keene; Daniel Stern; Charles R. Lawrence (10 July 2006). "Spitzer Observations of the Dusty Warped Disk of Centaurus A". Astrophysical Journal. 645 Nummer = 2 (2): 1092–1101. arXiv: astro-ph/0601135 . Bibcode:2006ApJ...645.1092Q. doi:10.1086/504418. S2CID   18443587.
  30. ↑ F. Aharonian; A. G. Akhperjanian; G. Anton; U. Barres de Almeida; A. R. Bazer-Bachi (10 April 2009). "DISCOVERY OF VERY HIGH ENERGY γ-RAY EMISSION FROM CENTAURUS A WITH H.E.S.S.". Astrophysical Journal. 695 (1): L40–L44. arXiv: 0903.1582 . Bibcode:2009ApJ...695L..40A. doi:10.1088/0004-637x/695/1/l40. S2CID   18160745.
  31. ↑ J. Abraham; P. Abreu; M. Aglietta; C. Aguirre; D. Allard (1 April 2008). "Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei". Astroparticle Physics. 29 (3): 188–204. arXiv: 0712.2843 . Bibcode:2008APh....29..188P. doi:10.1016/j.astropartphys.2008.01.002.
  32. 1 2 A. Sandage; J. Bedke (1994). Carnegie Atlas of Galaxies. Washington, D.C.: Carnegie Institution of Washington. ISBN   978-0-87279-667-6.
  33. ↑ H. Arp (1966). "Atlas of Peculiar Galaxies". Astrophysical Journal Supplement. 14: 1–20. Bibcode:1966ApJS...14....1A. doi:10.1086/190147.
  34. ↑ W. Baade; R. Minkowski (1954). "On the Identification of Radio Sources". Astrophysical Journal. 119: 215–231. Bibcode:1954ApJ...119..215B. doi:10.1086/145813.
  35. ↑ P. W. Hodge; R. C. Kennicutt Jr. (1982). "An atlas of H II regions in 125 galaxies". Astrophysical Journal. 88: 296–328. Bibcode:1983AJ.....88..296H. doi:10.1086/113318.
  36. ↑ "NASA/IPAC Extragalactic Database". Results for extended name search on Centaurus A. Retrieved 7 March 2007.
  37. ↑ R. Evans; R. H. McNaught; C. Humphries (1986). "Supernova 1986G in NGC 5128". IAU Circular. 4208: 1. Bibcode:1986IAUC.4208....1E.
  38. 1 2 M. M. Phillips; A. C. Phillips; S. R. Heathcote; V. M. Blanco; et al. (1987). "The type 1a supernova 1986G in NGC 5128 – Optical photometry and spectra". Publications of the Astronomical Society of the Pacific. 99: 592–605. Bibcode:1987PASP...99..592P. doi:10.1086/132020.
  39. ↑ "Supernova SN 2016adj in the peculiar galaxy NGC 5128 ("Centaurus A") – 9 Feb. 2016 – The Virtual Telescope Project 2.0". 9 February 2016.
  40. ↑ "ATel #8651: Bright PSN in NGC5128 (Centaurus A) Discovered By Backyard Observatory Supernova Search (BOSS)". ATel.
  41. ↑ "ATel #8655: Tentative Spectroscopic Classification of Bright PSN in NGC 5128 (Centaurus A)". ATel.
  42. ↑ "ATel #8657: CSP Spectroscopic Classification of AT 2016adj in NGC 5128 (Centaurus A)". ATel.
  43. ↑ "AT 2020nqq". Transient Name Server. IAU . Retrieved 5 September 2024.
  44. 1 2 Rejkuba, M. (2004). "The distance to the giant elliptical galaxy NGC 5128". Astronomy and Astrophysics. 413 (3): 903–912. arXiv: astro-ph/0310639 . Bibcode:2004A&A...413..903R. doi:10.1051/0004-6361:20034031. S2CID   15938660.
  45. ↑ Majaess, D.; Turner, D.; Lane, D. (2009). "Type II Cepheids as Extragalactic Distance Candles". Acta Astronomica. 59 (4): 403. arXiv: 0909.0181 . Bibcode:2009AcA....59..403M.
  46. ↑ I. D. Karachentsev; M. E. Sharina; A. E. Dolphin; E. K. Grebel; et al. (2002). "New distances to galaxies in the Centaurus A group". Astronomy and Astrophysics. 385 (1): 21–31. Bibcode:2002A&A...385...21K. doi: 10.1051/0004-6361:20020042 .
  47. ↑ R. B. Tully (1988). Nearby Galaxies Catalog. Cambridge: Cambridge University Press. ISBN   978-0-521-35299-4.
  48. ↑ P. Fouque; E. Gourgoulhon; P. Chamaraux; G. Paturel (1992). "Groups of galaxies within 80 Mpc. II – The catalogue of groups and group members". Astronomy and Astrophysics Supplement. 93: 211–233. Bibcode:1992A&AS...93..211F.
  49. ↑ A. Garcia (1993). "General study of group membership. II – Determination of nearby groups". Astronomy and Astrophysics Supplement. 100: 47–90. Bibcode:1993A&AS..100...47G.
  50. ↑ I. D. Karachentsev (2005). "The Local Group and Other Neighboring Galaxy Groups". Astronomical Journal. 129 (1): 178–188. arXiv: astro-ph/0410065 . Bibcode:2005AJ....129..178K. doi:10.1086/426368. S2CID   119385141.
  51. ↑ Dumont, Antoine; Seth, Anil C.; Strader, Jay; Voggel, Karina; Sand, David J.; Hughes, Allison K.; Caldwell, Nelson; Crnojević, Denija; Mateo, Mario; Bailey, John I.; Forbes, Duncan A. (2022). "A Population of Luminous Globular Clusters and Stripped Nuclei with Elevated Mass to Light Ratios around NGC 5128". The Astrophysical Journal. 929 (2): 147. arXiv: 2112.04504 . Bibcode:2022ApJ...929..147D. doi: 10.3847/1538-4357/ac551c . S2CID   245005855.
  52. ↑ Roopesh Ojha; M. Kadler; M. Böck; R. Booth; M. S. Dutka (30 December 2009). "TANAMI: Milliarcsecond Resolution Observations of Extragalactic Gamma-ray Sources". 2009 Fermi Symposium. arXiv: 1001.0059 . Bibcode:2010arXiv1001.0059O.
  53. ↑ Inner Radio Lobes of Centaurus A (NGC 5128). Archived 16 September 2016 at the Wayback Machine
  54. ↑ "Aintno Catalog". astronomy-mall.com.
  55. ↑ "Firestorm of Star Birth in Galaxy Centaurus A". NASA. 7 March 2012. Retrieved 27 September 2012.

Sources


This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.