NGC 4945

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NGC 4945
Spiral Galaxy NGC 4945.jpg
NGC 4945 image take by the MPG/ESO 2.2-metre telescope at La Silla Observatory
Observation data (J2000 epoch)
Constellation Centaurus
Right ascension 13h 05m 27.5s [1]
Declination −49° 28 06 [1]
Redshift 563 ± 3 km/s [1]
Distance 11.7 Mly (3.6 Mpc) [2]
Apparent magnitude  (V)9.3 [1]
Characteristics
Type SB(s)cd [1]
Apparent size  (V)20.0 × 3.8 [1]
Other designations
PGC 45279, [1] Caldwell 83
The location of NGC 4945 (labelled in red) NGC4945Location.png
The location of NGC 4945 (labelled in red)

NGC 4945 (also known as Caldwell 83) is a barred spiral galaxy in the constellation Centaurus, visible near the star Xi Centauri. [3] The galaxy was discovered by James Dunlop in 1826 and is thought to be similar to the Milky Way Galaxy, although X-ray observations show that NGC 4945 has an unusual energetic Seyfert 2 nucleus that might house a supermassive black hole. [4] Around the nucleus of the galaxy, there is a dense disk of dust and gas, along with many dense star clusters. [5] This object has an estimated mass of 1.4+1.4
−0.7
×1011  M
. [6]

Contents

Two supernovae have been observed in NGC 4945: SN 2005af (Type II, mag. 12.8), [7] and SN 2011ja (type IIP, mag. 14). [8]

Galaxy group

NGC 4945 one of the brightest galaxies of the Centaurus A/M83 Group, a large, nearby group of galaxies. The galaxy is the second brightest galaxy in the subgroup centered on Centaurus A. [2] [9]

NGC 4945 is the title of a song by Brett Domino on the album "Funk".

Related Research Articles

<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 23 February 1752 at the Cape of Good Hope. Charles Messier added it to his catalogue of nebulous objects in March 1781.

<span class="mw-page-title-main">Messier 61</span> Galaxy in the constellation Virgo

Messier 61 is an intermediate barred spiral galaxy in the Virgo Cluster of galaxies. It was first discovered by Barnaba Oriani on May 5, 1779, six days before Charles Messier discovered the same galaxy. Messier had observed it on the same night as Oriani but had mistaken it for a comet. Its distance has been estimated to be 45.61 million light years from the Milky Way Galaxy. It is a member of the M61 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.

<span class="mw-page-title-main">Centaurus A</span> Radio galaxy in the constellation Centaurus

Centaurus A 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 and distance. NGC 5128 is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers. The galaxy is also the fifth-brightest in the sky, making it an ideal amateur astronomy target. It is only visible from the southern hemisphere and low northern latitudes.

<span class="mw-page-title-main">NGC 300</span> Galaxy in the constellation Sculptor

NGC 300 (also known as Caldwell 70) is a spiral galaxy in the constellation Sculptor. It is one of the closest galaxies to the Local Group, and probably lies between the latter and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group. It is inclined at an angle of 42° when viewed from Earth and shares many characteristics of the Triangulum Galaxy. It is 94,000 light-years in diameter, somewhat smaller than the Milky Way, and has an estimated mass of (2.9 ± 0.2) × 1010M.

<span class="mw-page-title-main">Messier 96</span> Galaxy in the constellation Leo

Messier 96 is an intermediate spiral galaxy about 31 million light-years away in the constellation Leo.

<span class="mw-page-title-main">Messier 106</span> Galaxy in the constellation Canes Venatici

Messier 106 is an intermediate spiral galaxy in the constellation Canes Venatici. It was discovered by Pierre Méchain in 1781. M106 is at a distance of about 22 to 25 million light-years away from Earth. M106 contains an active nucleus classified as a Type 2 Seyfert, and the presence of a central supermassive black hole has been demonstrated from radio-wavelength observations of the rotation of a disk of molecular gas orbiting within the inner light-year around the black hole. NGC 4217 is a possible companion galaxy of Messier 106.

<span class="mw-page-title-main">Sculptor Galaxy</span> Intermediate spiral galaxy in the constellation Sculptor

The Sculptor Galaxy is an intermediate spiral galaxy in the constellation Sculptor. The Sculptor Galaxy is a starburst galaxy, which means that it is currently undergoing a period of intense star formation.

<span class="mw-page-title-main">NGC 5253</span> Irregular galaxy in the M83 group of galaxies

NGC 5253 is an irregular galaxy in the constellation Centaurus. It was discovered by William Herschel on 15 March 1787.

<span class="mw-page-title-main">NGC 5033</span> Galaxy in the constellation Canes Venatici

NGC 5033 is an inclined spiral galaxy located in the constellation Canes Venatici. Distance estimates vary from between 38 and 60 million light years from the Milky Way. The galaxy has a very bright nucleus and a relatively faint disk. Significant warping is visible in the southern half of the disk. The galaxy's relatively large angular size and relatively high surface brightness make it an object that can be viewed and imaged by amateur astronomers. The galaxy's location relatively near Earth and its active galactic nucleus make it a commonly studied object for professional astronomers.

<span class="mw-page-title-main">NGC 5005</span> Galaxy in the constellation Canes Venatici

NGC 5005, also known as Caldwell 29, is an inclined spiral galaxy in the constellation Canes Venatici. The galaxy has a relatively bright nucleus and a bright disk that contains multiple dust lanes. The galaxy's high surface brightness makes it an object that is visible to amateur astronomers using large amateur telescopes.

<span class="mw-page-title-main">NGC 1566</span> Galaxy in the constellation Dorado

NGC 1566, sometimes known as the Spanish Dancer, is an intermediate spiral galaxy in the constellation Dorado, positioned about 3.5° to the south of the star Gamma Doradus. It was discovered on May 28, 1826 by Scottish astronomer James Dunlop. At 10th magnitude, it requires a telescope to view. The distance to this galaxy remains elusive, with measurements ranging from 6 Mpc up to 21 Mpc.

<span class="mw-page-title-main">NGC 1672</span> Galaxy in the constellation Dorado

NGC 1672 is a barred spiral galaxy located in the constellation Dorado. It was discovered by the astronomer James Dunlop on November 5, 1826. It was originally unclear whether it was a member of the Dorado Group, with some sources finding it to be a member and other sources rejecting its membership. However, recent tip of the red-giant branch (TRGB) measurements indicate that NGC 1672 is located at the same distance as other members, suggesting it is indeed a member of the Dorado Group.

<span class="mw-page-title-main">NGC 5962</span> Galaxy in the constellation Serpens

NGC 5962 is a spiral galaxy in the equatorial constellation of Serpens Caput. It was discovered by the Anglo-German astronomer William Herschel on March 21, 1784. The NGC 5962 galaxy is located at a distance of 120 million light years and is receding with a heliocentric radial velocity of 1,957 km/s. It is the brightest member of the eponymously-named NGC 5962 group, which overlaps with the nearby NGC 5970 group; the two groups may be gravitationally bound.

<span class="mw-page-title-main">NGC 1448</span> Galaxy in the constellation Horologium

NGC 1448 or NGC 1457 is an unbarred spiral galaxy seen nearly edge-on in the constellation Horologium. It is at a distance of 55 million light years from Earth. It was discovered by John Herschel in 1835.

<span class="mw-page-title-main">NGC 3642</span> Galaxy in the constellation Ursa Major

NGC 3642 is a spiral galaxy in the constellation Ursa Major. The galaxy has a low-ionization nuclear emission-line region. It is located at a distance of circa 30 million light years from Earth, which, given its apparent dimensions, means that NGC 3642 is about 50,000 light years across. The galaxy is characterised by an outer pseudoring, which was probably formed after the accretion of a gas rich dwarf galaxy.

<span class="mw-page-title-main">NGC 3147</span> Galaxy in the constellation Draco

NGC 3147 is a spiral galaxy located in the constellation Draco. It is located at a distance of circa 130 million light years from Earth, which, given its apparent dimensions, means that NGC 3147 is about 140,000 light years across. It was discovered by William Herschel on April 3, 1785. It is a Type II Seyfert galaxy.

<span class="mw-page-title-main">NGC 4939</span> Spiral galaxy in the constellation Virgo

NGC 4939 is a spiral galaxy located in the constellation Virgo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 4939 is about 190,000 light years across. It was discovered by William Herschel on March 25, 1786.

<span class="mw-page-title-main">NGC 6951</span> Galaxy in the constellation Cepheus

NGC 6951 is a barred spiral galaxy located in the constellation Cepheus. It is located at a distance of about 75 million light-years from Earth, which, given its apparent dimensions, means that NGC 6951 is about 100,000 light-years across. It was discovered by Jérôme Eugène Coggia in 1877 and independently by Lewis Swift in 1878.

<span class="mw-page-title-main">NGC 2985</span> Galaxy in the constellation Ursa Major

NGC 2985 is a spiral galaxy located in the constellation Ursa Major. It is located at a distance of circa 70 million light years from Earth, which, given its apparent dimensions, means that NGC 2985 is about 95,000 light years across. It was discovered by William Herschel on April 3, 1785.

<span class="mw-page-title-main">NGC 3393</span> Galaxy in the constellation Hydra

NGC 3393 is a barred spiral galaxy located in the constellation Hydra. It is located at a distance of circa 180 million light-years from Earth, which, given its apparent dimensions, means that NGC 3393 is about 140,000 light-years across. It was discovered by John Herschel on March 24, 1835. It is a Type II Seyfert galaxy. The galaxy is known to host two supermassive black holes, which are the nearest known pair of supermassive black holes to Earth.

References

  1. 1 2 3 4 5 6 7 "NASA/IPAC Extragalactic Database". Results for NGC 4945. Retrieved 2006-11-25.
  2. 1 2 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 .
  3. http://www.docdb.net/show_object.php?id=ngc_4945, NGC 4945 : DOCdb :Deep Sky Observer's Companion – the online database
  4. "Milky Way's Not-So-Distant Cousin Likely Harbors Supermassive Black Hole". Science Daily.
  5. Gaspar, G.; Díaz, R. J.; Mast, D.; Agüero, M. P.; Schirmer, M.; Günthardt, G.; Schmidt, E. O. (2022). "An Infrared View of the Obscured AGN Environment in NGC 4945". The Astronomical Journal. 163 (5): 230. arXiv: 2203.03678 . Bibcode:2022AJ....163..230G. doi: 10.3847/1538-3881/ac5ea4 . S2CID   247315251.
  6. Graham, Alister W. (November 2008), "Populating the Galaxy Velocity Dispersion - Supermassive Black Hole Mass Diagram: A Catalogue of (Mbh, σ) Values", Publications of the Astronomical Society of Australia, 25 (4): 167–175, arXiv: 0807.2549 , Bibcode:2008PASA...25..167G, doi:10.1071/AS08013, S2CID   89905.
  7. Transient Name Server entry for SN 2005af. Retrieved 25 March 2023.
  8. Transient Name Server entry for SN 2011ja. Retrieved 25 March 2023.
  9. 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.