NGC 3923

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NGC 3923
NGC 3923.png
Observation data (J2000 epoch)
Constellation Hydra
Right ascension 11h 51m 01.7s [1]
Declination −28° 48 22 [1]
Redshift 0.005801 +/- 0.00003 km/s [1]
Distance 71 ± 23 Mly (21.6 ± 7.0 Mpc) [1]
Apparent magnitude  (V)9.6
Characteristics
Type E4-5 [1]
Apparent size  (V)5.9 × 3.9 [1]
Notable featuresShell galaxy
Other designations
ESO 440- G 017, AM 1148-283, MCG -05-28-012, PGC 37061 [1]

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. [2] It was discovered by William Herschel on March 7, 1791.

Contents

Characteristics

NGC 3923 is an example of a shell galaxy where the stars in its halo are arranged in layers. NGC 3923 has up to 42 shells, the highest number among all shell galaxies, [3] and its shells are much more subtle than those of other shell galaxies. The shells of this galaxy are also symmetrical, while other shell galaxies are more skewed and asymmetrical. Concentric shells of stars enclosing a galaxy are quite common and are observed in many elliptical galaxies. In fact, every tenth elliptical galaxy exhibits this onion-like structure, which has never been observed in spiral galaxies. The shell-like structures are thought to develop as a consequence of galactic cannibalism, when a larger galaxy ingests a smaller companion. As the two centers approach, they initially oscillate about a common center, and this oscillation ripples outwards forming the shells of stars just as ripples on a pond spread when the surface is disturbed. [2]

Deep imaging also detected a stream extending from the core of NGC 3923 and a small elliptical galaxy on its axis, which is a probable progenitor of some of the shells. Another stream lies south of the core of NGC 3923, and a hook like structure lies at the northwest. [3]

Based on the velocity dispersion of the globular clusters of NGC 3923 the mass of the supermassive black hole of the galaxy was estimated to be (5.3±2.5)×108 M. [4]

Supernovae

One supernova has been detected in NGC 3923, SN 2018aoz, a type Ia supernova with peak magnitude 12.7. It was discovered on April 2, 2018. [5]

Nearby galaxies

NGC 3923 is the brightest galaxy in a galaxy group known as the NGC 3923 galaxy group. Within 25 arcminutes from NGC 3923 have been detected seven dwarf elliptical galaxies. NGC 3904 is located 37 arcminutes away. [6] Other galaxies in the group include NGC 3885, ESO 440-27, and ESO440-011. Other nearby galaxies include NGC 3617, NGC 3673, NGC 3717, NGC 3936, and NGC 4105. [7]

Related Research Articles

<span class="mw-page-title-main">Elliptical galaxy</span> Spherical or ovoid mass of stars

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.

<span class="mw-page-title-main">Messier 49</span> Elliptical galaxy in the constellation Virgo

Messier 49 is a giant elliptical galaxy about 56 million light-years away in the equatorial constellation of Virgo. This galaxy was discovered by astronomer Charles Messier in 1777.

<span class="mw-page-title-main">Messier 59</span> Elliptical galaxy in the constellation Virgo

Messier 59 or M59, also known as NGC 4621, is an elliptical galaxy in the equatorial constellation of Virgo. It is a member of the Virgo Cluster, with the nearest fellow member 8′ away and around 5 magnitudes fainter. The nearest cluster member of comparable brightness is the lenticular galaxy NGC 4638, which is around 17′ away. It and the angularly nearby elliptical galaxy Messier 60 were both discovered by Johann Gottfried Koehler in April 1779 when observing comet seeming close by. Charles Messier listed both in the Messier Catalogue about three days after Koehler's discovery.

<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">Messier 85</span> Elliptical galaxy in the constellation Coma Berenices

Messier 85 is a lenticular galaxy, or elliptical galaxy for other authors, in the Coma Berenices constellation. It is 60 million light-years away, and has a diameter of about 36.99 kiloparsecs across.

<span class="mw-page-title-main">Messier 89</span> Elliptical galaxy in the constellation Virgo

Messier 89 is an elliptical galaxy in the constellation Virgo. It was discovered by Charles Messier on March 18, 1781. M89 is a member of the Virgo Cluster of galaxies.

<span class="mw-page-title-main">NGC 4889</span> Galaxy in the constellation Coma Berenices

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.

<span class="mw-page-title-main">NGC 936</span> Galaxy in the constellation Cetus

NGC 936 is a barred lenticular galaxy in the constellation Cetus. It is at a distance of about 60 million light-years away from Earth. Its nucleus and prominent bar have high surface brightness. Because of the shape of the prominent bar, the nucleus and the ring of stars at the end of the barrel, the galaxy has been compared with the shape of a TIE fighter, from the Star Wars universe, and thus NGC 936 has been named Darth Vader’s Galaxy or Darth Vader’s Starfighter. By measuring the radial velocity of the disc, Kormendy found in 1986 that the disc is stable, which is the reason why it is so smooth.

<span class="mw-page-title-main">NGC 4494</span> Galaxy in the constellation Coma Berenices

NGC 4494 is an elliptical galaxy located in the constellation Coma Berenices. It is located at a distance of circa 45 million light years from Earth, which, given its apparent dimensions, means that NGC 4494 is about 60,000 light years across. It was discovered by William Herschel in 1785.

<span class="mw-page-title-main">NGC 7606</span> Galaxy in the constellation Aquarius

NGC 7606 is a spiral galaxy located in the constellation Aquarius. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 7606 is about 165,000 light years across. It was discovered by William Herschel on September 28, 1785. The galaxy is included in the Herschel 400 Catalogue. It lies 45 arcminutes northeast from psi2 Aquarii. It can be seen with a 4 inch telescope but its visibility is greatly affected by light pollution.

<span class="mw-page-title-main">NGC 1395</span> Galaxy in the constellation Eridanus

NGC 1395 is an elliptical galaxy located in the constellation Eridanus. It is located at a distance of circa 75 million light years from Earth, which, given its apparent dimensions, means that NGC 1395 is about 130,000 light years across. It was discovered by William Herschel on November 17, 1784. It is a member of the Eridanus Cluster.

<span class="mw-page-title-main">NGC 5982</span> Galaxy in the constellation Draco

NGC 5982 is an elliptical 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 5982 is about 100,000 light years across. It was discovered by William Herschel on May 25, 1788.

<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.

<span class="mw-page-title-main">NGC 3585</span> Galaxy in the constellation Hydra

NGC 3585 is an elliptical or a lenticular galaxy located in the constellation Hydra. It is located at a distance of circa 60 million light-years from Earth, which, given its apparent dimensions, means that NGC 3585 is about 80,000 light years across. It was discovered by William Herschel on December 9, 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 5846</span> Galaxy in the constellation Virgo

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.

<span class="mw-page-title-main">IC 1459</span> Elliptical galaxy in the constellation of Grus

IC 1459 is an elliptical galaxy located in the constellation Grus. It is located at a distance of circa 85 million light-years from Earth, which, given its apparent dimensions, means that IC 1459 is about 130,000 light-years across. It was discovered by Edward Emerson Barnard in 1892.

<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 4278</span> Galaxy in the constellation Coma Berenices

NGC 4278 is an elliptical galaxy located in the constellation Coma Berenices. It is located at a distance of circa 55 million light years from Earth, which, given its apparent dimensions, means that NGC 4278 is about 65,000 light years across. It was discovered by William Herschel on March 13, 1785. NGC 4278 is part of the Herschel 400 Catalogue and can be found about one and 3/4 of a degree northwest of Gamma Comae Berenices even with a small telescope.

<span class="mw-page-title-main">NGC 2974</span> Galaxy in the constellation Sextans

NGC 2974 is a lenticular galaxy located in the constellation Sextans. It is located at a distance of circa 90 million light years from Earth, which, given its apparent dimensions, means that NGC 2974 is about 90,000 light years across. It was discovered by William Herschel on January 6, 1785. NGC 2974 is located in the sky about 2 and a half degrees south-south east of Iota Hydrae and more than 6 degrees northeast of Alphard. A 10th magnitude star lies next to the galaxy, thus making it a challenging object at low magnifications. NGC 2974 is part of the Herschel 400 Catalogue.

References

  1. 1 2 3 4 5 6 7 "NASA/IPAC Extragalactic Database". Results for NGC 3923. Retrieved 2016-01-18.
  2. 1 2 "Hubble Spots the Layers of NGC 3923". NASA. May 15, 2015.
  3. 1 2 Bílek, M.; Cuillandre, J.-C.; Gwyn, S.; Ebrová, I.; Bartošková, K.; Jungwiert, B.; Jílková, L. (22 March 2016). "Deep imaging of the shell elliptical galaxy NGC 3923 with MegaCam". Astronomy & Astrophysics. 588: A77. arXiv: 1505.07146 . Bibcode:2016A&A...588A..77B. doi:10.1051/0004-6361/201526608. S2CID   55565466.
  4. Sadoun, Raphael; Colin, Jacques (11 October 2012). "-σ relation between supermassive black holes and the velocity dispersion of globular cluster systems". Monthly Notices of the Royal Astronomical Society: Letters. 426 (1): L51–L55. arXiv: 1204.0144 . Bibcode:2012MNRAS.426L..51S. doi: 10.1111/j.1745-3933.2012.01321.x . S2CID   117185846.
  5. "List of supernovae sorted by Magnitude for 2018".
  6. Sandage, A., Bedke, J. (1994). The Carnegie Atlas of Galaxies. Carnegie Institution of Washington.{{cite book}}: CS1 maint: multiple names: authors list (link)
  7. Makarov, Dmitry; Karachentsev, Igor (21 April 2011). "Galaxy groups and clouds in the local (z~ 0.01) Universe". Monthly Notices of the Royal Astronomical Society. 412 (4): 2498–2520. arXiv: 1011.6277 . Bibcode:2011MNRAS.412.2498M. doi: 10.1111/j.1365-2966.2010.18071.x . S2CID   119194025.
NGC 3923 (UV - GALEX NGC 3923GALEX.jpg
NGC 3923 (UV - GALEX