Sculptor Galaxy

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Sculptor Galaxy
NGC 253 Galaxy.jpg
Observation data (J2000 epoch)
Constellation Sculptor
Right ascension 00h 47m 33s [1]
Declination −25° 17′ 18″ [1]
Redshift 0.000811 [1]
Heliocentric radial velocity 243 ± 2 km/s [1]
Distance 11.4 ± 0.7 Mly
   (3.5 ± 0.2 Mpc) [2]
Apparent magnitude  (V)8.0 [1]
Characteristics
Type SAB(s)c [1]
Size36.96 kiloparsecs (120,500 light-years)
(diameter; D27 isophote)
Apparent size  (V)27′.5 × 6′.8 [1]
Other designations
Silver Coin Galaxy, [1] Silver Dollar Galaxy, [3] NGC 253, [1] UGCA 13, [1] PGC 2789 [1] Caldwell  65

The Sculptor Galaxy (also known as the Silver Coin Galaxy, Silver Dollar Galaxy, NGC 253, or Caldwell 65) 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.

Contents

Observation

Observational history

The galaxy was discovered by Caroline Herschel in 1783 during one of her systematic comet searches. [4] [5] About half a century later, John Herschel observed it using his 18-inch metallic mirror reflector at the Cape of Good Hope. [5] He wrote: "very bright and large (24′ in length); a superb object.... Its light is somewhat streaky, but I see no stars in it except 4 large and one very small one, and these seem not to belong to it, there being many near..." [5]

In 1961, Allan Sandage wrote in the Hubble Atlas of Galaxies that the Sculptor Galaxy is "the prototype example of a special subgroup of Sc systems....photographic images of galaxies of the group are dominated by the dust pattern. Dust lanes and patches of great complexity are scattered throughout the surface. Spiral arms are often difficult to trace.... The arms are defined as much by the dust as by the spiral pattern." [6] Bernard Y. Mills, working out of Sydney, discovered that the Sculptor Galaxy is also a fairly strong radio source. [5]

In 1998, the Hubble Space Telescope took a detailed image of NGC 253. [7]

Amateur

As one of the brightest galaxies in the sky, the Sculptor Galaxy can be seen through binoculars and is near the star Beta Ceti. It is considered one of the most easily viewed galaxies in the sky after the Andromeda Galaxy. [5] [8]

The Sculptor Galaxy is a good target for observation with a telescope with a 300 mm diameter or larger. [8] In such telescopes, it appears as a galaxy with a long, oval bulge and a mottled galactic disc. [8] Although the bulge appears only slightly brighter than the rest of the galaxy, it is fairly extended compared to the disk. [8] In 400 mm scopes and larger, a dark dust lane northwest of the nucleus is visible, and over a dozen faint stars can be seen superimposed on the bulge. [8] Some people claim to have observed the galaxy with the unaided eye under exceptional viewing conditions.

Features

Three-dimensional simulation of ALMA observations of the outflows. Three-dimensional view of ALMA observations of the outflows from NGC 253.jpg
Three-dimensional simulation of ALMA observations of the outflows.
Detail of NGC 253 by Hubble Space Telescope. (Credit: HST/NASA/ESA). NGC 253.jpg
Detail of NGC 253 by Hubble Space Telescope. (Credit: HST/NASA/ESA).

The Sculptor Galaxy is located at the center of the Sculptor Group, one of the nearest groups of galaxies to the Milky Way. [10] The Sculptor Galaxy (the brightest galaxy in the group and one of the intrinsically brightest galaxies in the vicinity of ours, only surpassed by the Andromeda Galaxy and the Sombrero Galaxy [11] ) and the companion galaxies NGC 247, PGC 2881, PGC 2933, Sculptor-dE1, and UGCA 15 form a gravitationally-bound core near the center of the group. Most other galaxies associated with the Sculptor Group are only weakly gravitationally bound to this core. [10] [12]

Starburst

NGC 253's starburst has created several super star clusters on NGC 253's center (discovered with the aid of the Hubble Space Telescope): one with a mass of 1.5×106 solar masses, and absolute magnitude of at least −15, and two others with 5×104 solar masses and absolute magnitudes around −11; [13] later studies have discovered an even more massive cluster heavily obscured by NGC 253's interstellar dust with a mass of 1.4×107 solar masses, an age of around 5.7×106 years, and rich in Wolf-Rayet stars. [14] The super star clusters are arranged in an ellipse around the center of NGC 253, which from the Earth's perspective appears as a flat line. [15]

Star formation is also high in the northeast of NGC 253's disk, where a number of red supergiant stars can be found, and in its halo there are young stars as well as some amounts of neutral hydrogen. This, along with other peculiarities found in NGC 253, suggest that a gas-rich dwarf galaxy collided with it 200 million years ago, disturbing its disk and starting the present starburst. [16]

As happens in other galaxies suffering strong star formation such as Messier 82, NGC 4631, or NGC 4666, the stellar winds of the massive stars produced in the starburst as well as their deaths as supernovae have blown out material to NGC 253's halo in the form of a superwind that seems to be inhibiting star formation in the galaxy. [17]

Although supernovae are generally associated with starburst galaxies, only one supernova has been detected within the Sculptor Galaxy. [1] The supernova, named SN 1940E, is located approximately 54″ southwest of the galaxy's nucleus. It was discovered in November 1940. [18]

NGC 253 is close enough that classical novae can also be detected. The first confirmed nova in this galaxy was discovered at magnitude 19.6 on 12 July 2024, by BlackGEM, and designated AT 2024pid. [19]

Central black hole

Research suggests the presence of a supermassive black hole in the center of this galaxy with a mass estimated to be 5 million times that of the Sun, which is slightly heavier than Sagittarius A*. [20]

Distance estimates

At least two techniques have been used to measure distances to Sculptor in the past ten years.

Using the planetary nebula luminosity function method, an estimate of 10.89 +0.85
−1.24 million light years (or Mly; 3.34 +0.26
−0.38 Megaparsecs, or Mpc) was achieved in 2005. [2]

The Sculptor Galaxy is close enough that the tip of the red-giant branch (TRGB) method may also be used to estimate its distance. The estimated distance to Sculptor using this technique in 2004 yielded 12.8±1.2 Mly (3.94±0.37 Mpc). [21] [22]

A weighted average of the most reliable distance estimates gives a distance of 11.4±0.7 Mly (3.5±0.2 Mpc). [2]

Satellite

An international team of researchers has used the Subaru Telescope to identify a faint dwarf galaxy disrupted by NGC 253. The satellite galaxy is called NGC 253-dw2 and may not survive its next passage by its much larger host. The host galaxy may suffer some damage too if the dwarf is massive enough. [23] The interplay between the two galaxies is responsible for the disturbance in NGC 253's structure. [24]

See also

Related Research Articles

<span class="mw-page-title-main">Galaxy</span> Large gravitationally bound system of stars and interstellar matter

A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. The word is derived from the Greek galaxias (γαλαξίας), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a thousand stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies.

<span class="mw-page-title-main">Local Group</span> Group of galaxies that includes the Milky Way

The Local Group is the galaxy group that includes the Milky Way, where Earth is located. It has a total diameter of roughly 3 megaparsecs (10 million light-years; 9×1019 kilometres), and a total mass of the order of 2×1012 solar masses (4×1042 kg). It consists of two collections of galaxies in a "dumbbell" shape; the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two collections are separated by about 800 kiloparsecs (3×10^6 ly; 2×1019 km) and are moving toward one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster. The exact number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 members are known, most of which are dwarf galaxies.

<span class="mw-page-title-main">M81 Group</span> Galaxy group in Ursa Major and Camelopardalis

The M81 Group is a galaxy group in the constellations Ursa Major and Camelopardalis that includes the galaxies Messier 81 and Messier 82, as well as several other galaxies with high apparent brightnesses. The approximate center of the group is located at a distance of 3.6 Mpc, making it one of the nearest groups to the Local Group. The group is estimated to have a total mass of ×1012M☉. The M81 Group, the Local Group, and other nearby groups all lie within the Virgo Supercluster.

<span class="mw-page-title-main">Messier 82</span> Starburst galaxy in the constellation Ursa Major

Messier 82 (also known as NGC 3034, Cigar Galaxy or M82) is a starburst galaxy approximately 12 million light-years away in the constellation Ursa Major. It is the second-largest member of the M81 Group, with the D25 isophotal diameter of 12.52 kiloparsecs (40,800 light-years). It is about five times more luminous than the Milky Way and its central region is about one hundred times more luminous. The starburst activity is thought to have been triggered by interaction with neighboring galaxy M81. As one of the closest starburst galaxies to Earth, M82 is the prototypical example of this galaxy type. SN 2014J, a type Ia supernova, was discovered in the galaxy on 21 January 2014. In 2014, in studying M82, scientists discovered the brightest pulsar yet known, designated M82 X-2.

<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. It is the closest radio galaxy to Earth, as well as the closest BL Lac object, 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">Sombrero Galaxy</span> Galaxy in the constellation Virgo

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.

<span class="mw-page-title-main">NGC 404</span> Galaxy in the constellation Andromeda

NGC 404 is a field galaxy located about 10 million light years away in the constellation Andromeda. It was discovered by William Herschel in 1784, and is visible through small telescopes. NGC 404 lies just beyond the Local Group and does not appear gravitationally bound to it. It is located within 7 arc-minutes of second magnitude star Mirach, making it a difficult target to observe or photograph and granting it the nickname "Mirach's Ghost".

<span class="mw-page-title-main">Messier 94</span> Galaxy in the constellation Canes Venatici

Messier 94 is a spiral galaxy in the mid-northern constellation Canes Venatici. It was discovered by Pierre Méchain in 1781, and catalogued by Charles Messier two days later. Although some references describe M94 as a barred spiral galaxy, the "bar" structure appears to be more oval-shaped. The galaxy has two ring structures.

<span class="mw-page-title-main">Andromeda I</span> Dwarf galaxy in the constellation Andromeda

Andromeda I is a dwarf spheroidal galaxy (dSph) about 2.40 million light-years away in the constellation Andromeda. Andromeda I is part of the local group of galaxies and a satellite galaxy of the Andromeda Galaxy (M31). It is roughly 3.5 degrees south and slightly east of M31. As of 2005, it is the closest known dSph companion to M31 at an estimated projected distance of ~40 kpc or ~150,000 light-years.

<span class="mw-page-title-main">NGC 1569</span> Galaxy in the constellation Camelopardalis

NGC 1569 is a dwarf irregular galaxy in Camelopardalis. The galaxy is relatively nearby and consequently, the Hubble Space Telescope can easily resolve the stars within the galaxy. The distance to the galaxy was previously believed to be only 2.4 Mpc. However, in 2008 scientists studying images from Hubble calculated the galaxy's distance at nearly 11 million light-years away, about 4 million light-years farther than previously thought, meaning it is a member of the IC 342 group of galaxies.

<span class="mw-page-title-main">NGC 6822</span> Galaxy in the constellation Sagittarius

NGC 6822 is a barred irregular galaxy approximately 1.6 million light-years away in the constellation Sagittarius. Part of the Local Group of galaxies, it was discovered by E. E. Barnard in 1884, with a six-inch refractor telescope. It is the closest non-satellite galaxy to the Milky Way, but lies just outside its virial radius. It is similar in structure and composition to the Small Magellanic Cloud. It is about 7,000 light-years in diameter.

<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.

A super star cluster (SSC) is a very massive young open cluster that is thought to be the precursor of a globular cluster. These clusters called "super" because they are relatively more luminous and contain more mass than other young star clusters. The SSC, however, does not have to physically be larger than other clusters of lower mass and luminosity. They typically contain a very large number of young, massive stars that ionize a surrounding HII region or a so-called "Ultra dense HII region (UDHII)" in the Milky Way Galaxy or in other galaxies. An SSC's HII region is in turn surrounded by a cocoon of dust. In many cases, the stars and the HII regions will be invisible to observations in certain wavelengths of light, such as the visible spectrum, due to high levels of extinction. As a result, the youngest SSCs are best observed and photographed in radio and infrared. SSCs, such as Westerlund 1 (Wd1), have been found in the Milky Way Galaxy. However, most have been observed in farther regions of the universe. In the galaxy M82 alone, 197 young SSCs have been observed and identified using the Hubble Space Telescope.

<span class="mw-page-title-main">NGC 247</span> Galaxy in the constellation Cetus

NGC 247 is an intermediate spiral galaxy about 11.1 Mly away in the constellation Cetus. This distance was confirmed in late February 2011. Previous measurements showed that the galaxy was about 12.2 Mly away, but this was proved to be wrong. NGC 247 is a member of the Sculptor Group, and is 70 000 light years in diameter.

<span class="mw-page-title-main">NGC 625</span> Galaxy in the constellation of Phoenix

NGC 625 is a dwarf barred spiral galaxy about 12.7 Mly away in the constellation Phoenix. It was discovered on 2 September 1826 by Scottish astronomer James Dunlop. NGC 625 is a member of the Sculptor Group.

<span class="mw-page-title-main">NGC 4214</span> Galaxy in the constellation Canes Venatici

NGC 4214 is a dwarf barred irregular galaxy located around 10 million light-years away in the constellation Canes Venatici. It was discovered on 28 April 1785 by German-British astronomer William Herschel. NGC 4214 is a member of the M94 Group.

<span class="mw-page-title-main">NGC 4449</span> Galaxy in the constellation Canes Venatici

NGC 4449, also known as Caldwell 21, is an irregular Magellanic type galaxy in the constellation Canes Venatici, being located about 13 million light-years away. It is part of the M94 Group or Canes Venatici I Group that is relatively close to the Local Group hosting our Milky Way galaxy.

<span class="mw-page-title-main">NGC 1084</span> Galaxy in the constellation Eridanus

NGC 1084 is an unbarred spiral galaxy in the constellation Eridanus. It is located at a distance of about 63 million light-years away from the Milky Way. The galaxy was discovered by William Herschel on 10 January 1785. It has multiple spiral arms, which are not well defined. It belongs in the same galaxy group with NGC 988, NGC 991, NGC 1022, NGC 1035, NGC 1042, NGC 1047, NGC 1052 and NGC 1110. This group is in turn associated with the Messier 77 group.

<span class="mw-page-title-main">NGC 541</span> Galaxy in the constellation Cetus

NGC 541 is a lenticular galaxy located in the constellation Cetus. It is located at a distance of about 230 million light years from Earth, which, given its apparent dimensions, means that NGC 541 is about 130,000 light years across. It was discovered by Heinrich d'Arrest on October 30, 1864. It is a member of the Abell 194 galaxy cluster and is included in the Atlas of Peculiar Galaxies in the category galaxies with nearby fragments. NGC 541 is a radio galaxy of Fanaroff–Riley class I, also known as 3C 40A.

<span class="mw-page-title-main">NGC 3489</span> Galaxy in the constellation Leo

NGC 3489 is a lenticular galaxy located in the constellation Leo. It is located at a distance of about 30 million light years from Earth, which, given its apparent dimensions, means that NGC 3489 is about 30,000 light years across. It was discovered by William Herschel on April 8, 1784. NGC 3489 is a member of the Leo Group.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 "NASA/IPAC Extragalactic Database". Results for NGC 253. Retrieved 2006-11-25.
  2. 1 2 3 Rekola, R.; Richer, M. G.; McCall, Marshall L.; Valtonen, M. J.; Kotilainen, J. K.; Flynn, Chris (2005). "Distance to NGC 253 based on the planetary nebula luminosity function". Monthly Notices of the Royal Astronomical Society . 361 (1): 330–336. Bibcode:2005MNRAS.361..330R. doi: 10.1111/j.1365-2966.2005.09166.x .
  3. ↑ Nemiroff, R.; Bonnell, J., eds. (2006-04-21). "NGC 253: Dusty Island Universe". Astronomy Picture of the Day . NASA . Retrieved 2010-12-04.
  4. ↑ Dreyer, J. L. E. (1888). "A New General Catalogue of Nebulae and Clusters of Stars, being the Catalogue of the late Sir John F.W. Herschel, Bart., revised, corrected, and enlarged". Memoirs of the Royal Astronomical Society . 49: 1–237. Bibcode:1888MmRAS..49....1D.
  5. 1 2 3 4 5 Burnham, Robert (1978). Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System. Vol. Three, Pavo Through Vulpecula. Dover Publications, Inc. p.  1736. ISBN   978-0-486-24065-7.
  6. ↑ Sandage, Allan (1961). The Hubble Atlas of Galaxies. Washington: Carnegie Institution. Bibcode:1961hag..book.....S. ISBN   978-0-87279-629-4.
  7. ↑ "HubbleSite NewsCenter". Results for NGC 253. Retrieved 2007-04-05.
  8. 1 2 3 4 5 Kepple, George Robert; Sanner, Glen W. (1998). The Night Sky Observer's Guide. Vol. 2. Willmann-Bell, Inc. pp. 365, 371. ISBN   978-0-943396-60-6.
  9. ↑ "Starburst to Star Bust". European Southern Observatory. 24 July 2013. Retrieved 15 August 2013.
  10. 1 2 Karachentsev, I. D. (2005). "The Local Group and Other Neighboring Galaxy Groups". The Astronomical Journal . 129 (1): 178–188. arXiv: astro-ph/0410065 . Bibcode:2005AJ....129..178K. doi:10.1086/426368. S2CID   119385141.
  11. ↑ Karachentsev, Igor D.; Karachentseva, Valentina E.; Huchtmeier, Walter K.; Makarov, Dmitry I. (2003). "A Catalog of Neighboring Galaxies". The Astronomical Journal . 127 (4): 2031–2068. Bibcode:2004AJ....127.2031K. doi: 10.1086/382905 .
  12. ↑ Karachentsev, I. D.; Grebel, E. K.; Sharina, M. E.; Dolphin, A. E.; et al. (2003). "Distances to nearby galaxies in Sculptor". Astronomy and Astrophysics . 404 (1): 93–111. arXiv: astro-ph/0302045 . Bibcode:2003A&A...404...93K. doi:10.1051/0004-6361:20030170. S2CID   54977869.
  13. ↑ Watson, A. M.; Gallagher, J. S. III; Holtzman, J. A.; Hester, J. J.; et al. (1996). "The Discovery of Young, Luminous, Compact Stellar Clusters in the Starburst Galaxy NGC 253" (PDF). The Astronomical Journal . 112 (2): 534. Bibcode:1996AJ....112..534W. doi:10.1086/118032.
  14. ↑ Kornei, Katherine A.; McCrady, Nate (2009). "A Young Super Star Cluster in the Nuclear Region of NGC 253". The Astrophysical Journal . 697 (2): 1180–1186. arXiv: 0902.4027 . Bibcode:2009ApJ...697.1180K. doi:10.1088/0004-637X/697/2/1180. S2CID   18960325.
  15. ↑ Levy, Rebecca C.; Bolatto, Alberto D.; Leroy, Adam K.; Sormani, Mattia C.; Emig, Kimberly L.; Gorski, Mark; Lenkić, Laura; Mills, Elisabeth A. C.; Tarantino, Elizabeth; Teuben, Peter; Veilleux, Sylvain; Walter, Fabian (2022). "The Morpho-kinematic Architecture of Super Star Clusters in the Center of NGC 253". The Astrophysical Journal. 935 (1): 19. arXiv: 2206.04700 . Bibcode:2022ApJ...935...19L. doi: 10.3847/1538-4357/ac7b7a . S2CID   249605852.
  16. ↑ Davidge, T. J. (2010). "Shaken, Not Stirred: The Disrupted Disk of the Starburst Galaxy NGC 253". The Astrophysical Journal . 725 (1): 1342–1365. arXiv: 1011.3006 . Bibcode:2010ApJ...725.1342D. doi:10.1088/0004-637X/725/1/1342. S2CID   118649411.
  17. ↑ Bolatto, Alberto D.; Warren, Steven R.; Leroy, Adam K.; Walter, Fabian; et al. (2013). "Suppression of star formation in the galaxy NGC 253 by a starburst-driven molecular wind". Nature . 499 (7459): 450–453. arXiv: 1307.6259 . Bibcode:2013Natur.499..450B. doi:10.1038/nature12351. PMID   23887428. S2CID   4366091.
  18. ↑ Barbon, R.; Cappellaro, E.; Ciatti, F.; Turatto, M.; Kowal, C. T. (1984). "A revised supernova catalogue". Astronomy & Astrophysics Supplement Series . 58: 735–750. Bibcode:1984A&AS...58..735B.
  19. ↑ Transient Name Server entry for AT 2024pid. Retrieved 13 July 2024.
  20. ↑ "Black Hole Naps Amidst Stellar Chaos". Jet Propulsion Laboratory . NASA. June 11, 2013.
  21. ↑ Karachentsev, Igor D.; Karachentseva, Valentina E.; Hutchmeier, Walter K.; Makarov, Dmitry I. (2004). "A Catalog of Neighboring Galaxies". The Astronomical Journal . 127 (4): 2031–2068. Bibcode:2004AJ....127.2031K. doi: 10.1086/382905 .
  22. ↑ Karachentsev, I. D.; Kashibadze, O. G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics . 49 (1): 3–18. Bibcode:2006Ap.....49....3K. doi:10.1007/s10511-006-0002-6. S2CID   120973010.
  23. ↑ "Galactic Space Oddity Discovered". Subaru Telescope . National Astronomical Observatory of Japan. February 8, 2016. Retrieved February 9, 2016.
  24. ↑ Romanowsky, Aaron J.; Martínez-Delgado, David; Martin, Nicolas F.; Morales, Gustavo; et al. (2016). "Satellite accretion in action: a tidally disrupting dwarf spheroidal around the nearby spiral galaxy NGC 253". Monthly Notices of the Royal Astronomical Society . 456 (1): 103–107. arXiv: 1512.03815 . Bibcode:2016MNRAS.457L.103R. doi: 10.1093/mnrasl/slv207 .
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