NGC 4939

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NGC 4939
Ngc4939-hst-606.png
Observation data (J2000 epoch)
Constellation Virgo
Right ascension 13h 04m 14.4s [1]
Declination −10° 20 22 [1]
Redshift 0.010374 ± 0.000013 [1]
Heliocentric radial velocity 3,110 ± 4 km/s [1]
Distance 118 ± 30 Mly (36.1 ± 9.4 Mpc) [1]
Apparent magnitude  (V)11.3 [2]
Characteristics
Type SA(s)bc [1]
Apparent size  (V)5.5 × 2.8 [1]
Notable featuresSeyfert galaxy
Other designations
MCG -02-33-104, PGC 45170 [1]

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. [3]

Contents

Characteristics

NGC 4939 has been characterised as a Seyfert galaxy, a galaxy category which features bright point-like nuclei. NGC 4939 is a type II Seyfert galaxy. Its X-ray spectrum is more consistent with a Compton-thick cold reflection source, which means that the source is hidden behind dense material, mainly gas and dust, and the X-rays observed have been reflected, but a Compton-thin transmission model could not be ruled out. [4] The equivalent width of the FeKα line is large, indicating too that it is a Compton-thick source. [5] Further observations by Swift Observatory confirmed its Compton-thick nature. [6] The source of activity in the active galactic nuclei is a supermassive black hole (SMBH) lying at the centre of the galaxy. The SMBH at the centre of NGC 4939 is accreting material with a rate of 0.077 M per year. [7] The black hole has been detected in hard X-rays, which are not absorbed by the Compton-thick column, by INTEGRAL. [8]

The galaxy has a large elliptical bulge and maybe a weak bar. It is a grand design spiral galaxy, with two tightly wrapped arms emanating from the bulge. The arms are thin, smooth and well defined and can be traced for nearly one and a half revolutions before fading. [9] Two symmetric arm sections or arcs are observed in the central part of the galaxy. [10] The galaxy is seen with an inclination of 56 degrees. The rotational speed of the galaxy is about 270 km/s. [11]

Supernovae

NGC 4939 has been home of five supernovae: SN 1968X (mag. 16), [12] SN 1973J (mag. 16), [13] SN 2008aw (Type II, mag. 15.9), [14] SN 2014B (Type IIP, mag. 17.0), [15] and SN 2020nif (Type II, mag. 16.1). [16]

Nearby galaxies

NGC 4939 belongs to a small galaxy group known as the NGC 4933 group, named after the multiple galaxy NGC 4933. [17] The group lies between the Local Supercluster and Hydra-Centaurus Supercluster. [18]

Related Research Articles

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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.

<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">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. Besides the two visible arms, it has two "anomalous arms" detectable using an X-ray telescope.

<span class="mw-page-title-main">NGC 3227</span> Galaxy in the constellation Leo

NGC 3227 is an intermediate spiral galaxy that is interacting with the dwarf elliptical galaxy NGC 3226. The two galaxies are one of several examples of a spiral with a dwarf elliptical companion that are listed in the Atlas of Peculiar Galaxies. Both galaxies may be found in the constellation Leo. It is a member of the NGC 3227 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 4945</span> Galaxy in the constellation Centaurus

NGC 4945 (also known as Caldwell 83) is a barred spiral galaxy in the constellation Centaurus, visible near the star Xi Centauri. 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. Around the nucleus of the galaxy, there is a dense disk of dust and gas, along with many dense star clusters. This object has an estimated mass of 1.4+1.4
−0.7
×1011 M
.

<span class="mw-page-title-main">NGC 5548</span> Type I Seyfert galaxy in the constellation Boötes

NGC 5548 is a Type I Seyfert galaxy with a bright, active nucleus. This activity is caused by matter flowing onto a 65 million solar mass (M) supermassive black hole at the core. Morphologically, this is an unbarred lenticular galaxy with tightly-wound spiral arms, while shell and tidal tail features suggest that it has undergone a cosmologically-recent merger or interaction event. NGC 5548 is approximately 245 million light years away and appears in the constellation Boötes. The apparent visual magnitude of NGC 5548 is approximately 13.3 in the V band.

<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 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 4639</span> Galaxy in the constellation Virgo

NGC 4639 is a barred spiral galaxy located in the equatorial constellation of Virgo. It was discovered by German-born astronomer William Herschel on April 12, 1784. John L. E. Dreyer described it as "pretty bright, small, extended, mottled but not resolved, 12th magnitude star 1 arcmin to southeast". This is a relatively nearby galaxy, lying approximately 72 million light-years away from the Milky Way. It is a companion to NGC 4654, and the two appear to have interacted roughly 500 million years ago. NGC 4639 is a member of the Virgo Cluster.

<span class="mw-page-title-main">NGC 4051</span> Galaxy in the constellation Ursa Major

NGC 4051 is an intermediate spiral galaxy in the constellation of Ursa Major. It was discovered on 6 February 1788 by John Herschel.

<span class="mw-page-title-main">IC 2560</span> Spiral galaxy in the constellation Antlia

IC 2560 is a spiral galaxy lying over 110 million light-years away from Earth in the constellation of Antlia. It was discovered by Lewis Swift in 1897.

<span class="mw-page-title-main">NGC 4102</span> Galaxy in the constellation Ursa Major

NGC 4102 is an intermediate barred spiral galaxy located in the northern constellation of Ursa Major. It is visible in a small telescope and has an apparent visual magnitude of 11.2. The galaxy was discovered April 12, 1789 by William Herschel. J. L. E. Dreyer described it as "bright, pretty small, round, brighter middle and bright nucleus". This galaxy is located at a distance of 60 million light years and is receding with a heliocentric radial velocity of 837 km/s. It is a member of the Ursa Major group of galaxies.

<span class="mw-page-title-main">NGC 4424</span> Spiral galaxy in the constellation Virgo

NGC 4424 is a spiral galaxy located in the equatorial constellation of Virgo. It was discovered February 27, 1865 by German astronomer Heinrich Louis d'Arrest. This galaxy is located at a distance of 13.5 million light years and is receding with a heliocentric radial velocity of 442 km/s. It has a morphological class of SB(s)a, which normally indicates a spiral galaxy with a barred structure (SB), no inner ring feature (s), and tightly-wound spiral arms (a). The galactic plane is inclined at an angle of 62° to the line of sight from the Earth. It is a likely member of the Virgo Cluster of galaxies.

<span class="mw-page-title-main">NGC 4699</span> Spiral galaxy in the constellation Virgo

NGC 4699 is an intermediate spiral galaxy located in the constellation Virgo. It is located at a distance of about 65 million light years from Earth, which, given its apparent dimensions, means that NGC 4699 is about 85,000 light years across. It was discovered by William Herschel in 1786. It is a member of the NGC 4699 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">NGC 3941</span> Galaxy in the constellation Ursa Major

NGC 3941 is a barred lenticular galaxy located in the constellation Ursa Major. It is located at a distance of circa 40 million light years from Earth, which, given its apparent dimensions, means that NGC 3941 is about 40,000 light years across. It was discovered by William Herschel in 1787.

<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 about 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.

<span class="mw-page-title-main">NGC 536</span> Galaxy in the constellation Andromeda

NGC 536 is a barred spiral galaxy located in the constellation Andromeda. It is located at a distance of circa 200 million light-years from Earth, which, given its apparent dimensions, means that NGC 536 is about 180,000 light years across. It was discovered by William Herschel on September 13, 1784. It is a member of Hickson Compact Group 10, which also includes the galaxies NGC 529, NGC 531, and NGC 542. It belongs to the Perseus–Pisces Supercluster.

<span class="mw-page-title-main">NGC 7130</span> Galaxy in the constellation Piscis Austrinus

NGC 7130 is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 220 million light years from Earth, which, given its apparent dimensions, means that NGC 7130 is about 100,000 light years across. It was discovered by John Herschel on September 25, 1834, and discovered independently by Lewis Swift on September 17, 1897. The location of the galaxy given in the New General Catalogue was off by 30 arcminutes in declination from the location of the galaxy.

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

NGC 6951 is a barred spiral galaxy located in 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 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, 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 8 "NASA/IPAC Extragalactic Database". Results for NGC 4939. Retrieved 2016-01-18.
  2. "Revised NGC Data for NGC 4939". spider.seds.org. Retrieved 25 November 2018.
  3. Seligman, Courtney. "NGC 4939 (= PGC 45170)". Celestial Atlas. Retrieved 19 November 2018.
  4. Maiolino, R.; Salvati, M.; Bassani, L.; Dadina, M.; della Ceca, R.; Matt, G.; Risaliti, G.; Zamorani, G. (October 1998). "Heavy obscuration in X-ray weak AGNs". Astronomy and Astrophysics. 338: 781–794. arXiv: astro-ph/9806055 . Bibcode:1998A&A...338..781M.
  5. Dadina, M. (4 October 2006). "BeppoSAX observations in the 2–100 keV band of the nearby Seyfert galaxies: an atlas of spectra". Astronomy & Astrophysics. 461 (3): 1209–1252. doi: 10.1051/0004-6361:20065734 .
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  7. Diamond-Stanic, Aleksandar M.; Rieke, George H. (20 February 2012). "The relationship between black hole growth and star formation in Seyfert galaxies". The Astrophysical Journal. 746 (2): 168. arXiv: 1106.3565 . Bibcode:2012ApJ...746..168D. doi:10.1088/0004-637X/746/2/168. S2CID   119277531.
  8. "IGR J13042-1020: a massive black hole in spiral galaxy NGC 4939". sci.esa.int. ESA. 11 June 2010.
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  11. Mitchell, Carl J.; Sellwood, J. A.; Williams, T. B.; Spekkens, Kristine; Kuzio de Naray, Rachel; Bixel, Alex (23 February 2018). "The RINGS Survey. III. Medium-resolution H-alpha Fabry–Pérot Kinematic Data Set". The Astronomical Journal. 155 (3): 123. arXiv: 1801.07750 . Bibcode:2018AJ....155..123M. doi: 10.3847/1538-3881/aaabb8 . S2CID   59472535.
  12. Transient Name Server entry for SN 1968X. Retrieved 24 March 2023.
  13. Transient Name Server entry for SN 1973J. Retrieved 24 March 2023.
  14. Transient Name Server entry for SN 2008aw. Retrieved 24 March 2023.
  15. Transient Name Server entry for SN 2014B. Retrieved 24 March 2023.
  16. Transient Name Server entry for SN 2020nif. Retrieved 24 March 2023.
  17. 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.
  18. Richter, O. -G.; Huchtmeier, W. K. (1 March 1987). "HI observations of galaxies in between the Local and the Hydra/Centaurus superclusters". Astronomy and Astrophysics Supplement Series. 68: 427–467. Bibcode:1987A&AS...68..427R. ISSN   0365-0138.