NGC 4631

Last updated
NGC 4631
NGC 4631 HST.jpg
An image of NGC 4631 taken with Hubble Space Telescope
Observation data (J2000 epoch)
Constellation Canes Venatici [1]
Right ascension 12h 42m 08.0s [2]
Declination +32° 32′ 29″ [2]
Redshift 606 ± 3 km/s [2]
Distance 30 Mly
Apparent magnitude  (V)9.8 [2]
Characteristics
Type SB(s)d [2]
Apparent size  (V)15′.5 × 2′.7 [2]
Notable featuresedge-on
Other designations
Whale Galaxy, [3] UGC 7865, [2] PGC 42637, [2] Arp 281, [2] Caldwell  32

NGC 4631 (also known as the Whale Galaxy or Caldwell 32) is a barred spiral galaxy in the constellation Canes Venatici about 30 million light years away from Earth. This galaxy's slightly distorted wedge shape gives it the appearance of a herring or a whale, hence its nickname. [3] 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.

Contents

Starburst and superwind

NGC 4631 mosaic of two HST images; 7.2'x2' view NGC 4631 Hubble mosaic.jpg
NGC 4631 mosaic of two HST images; 7.2′x2′ view

NGC 4631 contains a central starburst, which is a region of intense star formation. The strong star formation is evident in the emission from ionized hydrogen [4] and interstellar dust heated by the stars formed in the starburst. [5] The most massive stars that form in star formation regions only burn hydrogen gas through fusion for a short period of time, after which they explode as supernovae. So many supernovae have exploded in the center of NGC 4631 that they are blowing gas out of the plane of the galaxy. This superwind can be seen in X-rays [6] and in spectral line emission. [4] The gas from this superwind has produced a giant, diffuse corona of hot, X-ray emitting gas around the whole galaxy. [7]

Although no supernovae have been observed in NGC 4631 yet, a luminous red nova, designated AT 2021biy, was discovered on 29 January 2021 (type LRN, mag. 18.1). [8]

Nearby galaxies and galaxy group

NGC 4631 has a nearby companion dwarf elliptical galaxy, NGC 4627. NGC 4627 and NGC 4631 together were listed in the Atlas of Peculiar Galaxies as an example of a "double galaxy" or a galaxy pair. [9]

NGC 4631 and NGC 4627 are part of the NGC 4631 Group, a group of galaxies that also includes the interacting galaxies NGC 4656 and NGC 4657. [10] [11] [12] [13] However, exact group identification is problematic because this galaxy and others lie in a part of the sky that is relatively crowded. Estimates of the number of galaxies in this group range from 5 [10] to 27, [13] and all studies identify very different member galaxies for this group.

See also

Related Research Articles

<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">Messier 81</span> Spiral galaxy in the constellation Ursa Major

Messier 81 (also known as NGC 3031 or Bode's Galaxy) is a grand design spiral galaxy about 12 million light-years away in the constellation Ursa Major. It has a D25 isophotal diameter of 29.44 kiloparsecs (96,000 light-years). Because of its relative proximity to the Milky Way galaxy, large size, and active galactic nucleus (which harbors a 70 million M☉ supermassive black hole), Messier 81 has been studied extensively by professional astronomers. The galaxy's large size and relatively high brightness also makes it a popular target for amateur astronomers. In late February 2022, astronomers reported that M81 may be the source of FRB 20200120E, a repeating fast radio burst.

<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">Messier 95</span> Galaxy in the constellation Leo

Messier 95, also known as M95 or NGC 3351, is a barred spiral galaxy about 33 million light-years away in the zodiac constellation Leo. It was discovered by Pierre Méchain in 1781, and catalogued by compatriot Charles Messier four days later. In 2012 its most recent supernova was discovered.

<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 7331</span> Galaxy in the constellation Pegasus

NGC 7331, also known as Caldwell 30, is an unbarred spiral galaxy about 40 million light-years (12 Mpc) away in the constellation Pegasus. It was discovered by William Herschel in 1784. NGC 7331 is the brightest galaxy in the field of a visual grouping known as the NGC 7331 Group of galaxies. In fact, the other members of the group, NGC 7335, 7336, 7337 and 7340, lie far in the background at distances of approximately 300-350 million light years.

<span class="mw-page-title-main">NGC 4565</span> Galaxy in the constellation Coma Berenices

NGC 4565 is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. It lies close to the North Galactic Pole and has a visual magnitude of approximately 10. It is known as the Needle Galaxy for its narrow profile. First recorded in 1785 by William Herschel, it is a prominent example of an edge-on spiral galaxy.

The NGC 4631 Group is a poorly defined group of galaxies, about 25 million light-years from Earth in the Coma Berenices and Canes Venatici constellations.

<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 1808</span> Galaxy in the constellation Columba

NGC 1808 is a barred spiral galaxy located in the southern constellation of Columba, about two degrees to the south and east of Gamma Caeli. It was discovered by Scottish astronomer James Dunlop, who described it as a "faint nebula". The galaxy is a member of the NGC 1808 group, which is part of the larger Dorado Group.

<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 2782</span> Galaxy in the constellation Lynx

NGC 2782 is a peculiar spiral galaxy that formed after a galaxy merger in the constellation Lynx. The galaxy lies 75 million light years away from Earth, which means, given its apparent dimensions, that NGC 2782 is approximately 100,000 light years across. NGC 2782 has an active galactic nucleus and it is a starburst and a type 1 Seyfert galaxy. NGC 2782 is mentioned in the Atlas of Peculiar Galaxies in the category galaxies with adjacent loops.

<span class="mw-page-title-main">NGC 4647</span> Spiral galaxy in the constellation Virgo

NGC 4647 is an intermediate spiral galaxy estimated to be around 63 million light-years away in the constellation of Virgo. It was discovered by astronomer William Herschel on March 15, 1784. NGC 4647 is listed along with Messier 60 as being part of a pair of galaxies called Arp 116; their designation in Halton Arp's Atlas of Peculiar Galaxies. The galaxy is located on the outskirts of the Virgo Cluster.

<span class="mw-page-title-main">Coma I</span> Galaxy cluster in constellation Coma Berenices

The Coma I Group is a group of galaxies located about 14.5 Mpc (47.3 Mly) away in the constellation Coma Berenices. The brightest member of the group is NGC 4725. The Coma I Group is rich in spiral galaxies while containing few elliptical and lenticular galaxies. Coma I lies in the foreground of the more distant Coma and Leo clusters and is located within the Virgo Supercluster.

<span class="mw-page-title-main">NGC 3859</span> Spiral galaxy in the constellation Leo

NGC 3859 is a spiral galaxy located about 295 million light-years away in the constellation Leo. It was discovered by astronomer Édouard Stephan on March 23, 1884. The galaxy is a member of the Leo Cluster.

<span class="mw-page-title-main">NGC 5965</span> Spiral galaxy in the constellation Draco

NGC 5965 is a spiral galaxy located in the constellation Draco. It is located at a distance of circa 150 million light years from Earth, which, given its apparent dimensions, means that NGC 5965 is about 260,000 light years across. It was discovered by William Herschel on May 5, 1788.

<span class="mw-page-title-main">NGC 4302</span> Galaxy in the constellation Coma Berenices

NGC 4302 is an edge-on spiral galaxy located about 55 million light-years away in the constellation Coma Berenices. It was discovered by astronomer William Herschel on April 8, 1784 and is a member of the Virgo Cluster.

<span class="mw-page-title-main">NGC 1142</span> Interacting and distorted spiral galaxy in the constellation Cetus

NGC 1142 is a distorted spiral galaxy in the constellation of Cetus. It is located about 370 million light years away from Earth, which means, given its apparent dimensions, that NGC 1142 is approximately 170,000 light years across. It is a type 2 Seyfert galaxy. It interacts with the elliptical galaxy NGC 1141.

References

  1. ↑ R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation and Cambridge University Press. ISBN   978-0-933346-51-2.
  2. 1 2 3 4 5 6 7 8 9 "NASA/IPAC Extragalactic Database". Results for NGC 4631. Retrieved 2006-11-21.
  3. 1 2 "NGC 4631". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2006-08-22.
  4. 1 2 R. J. Rand; S. R. Kulkarni; J. J. Hester (1992). "Warm ionized gas in the edge-on galaxies NGC 4565 and NGC 4631". Astrophysical Journal. 396: 97–103. Bibcode:1992ApJ...396...97R. doi: 10.1086/171699 .
  5. ↑ G. J. Bendo; D. A. Dale; B. T. Draine; C. W. Engelbracht; et al. (2006). "The Spectral Energy Distribution of Dust Emission in the Edge-on Spiral Galaxy NGC 4631 as Seen with Spitzer and the James Clerk Maxwell Telescope". Astrophysical Journal. 652 (1): 283–305. arXiv: astro-ph/0607669 . Bibcode:2006ApJ...652..283B. doi:10.1086/508057. S2CID   119419587.
  6. ↑ Q. D. Wang; R. A. S. Walterbos; M. F. Steakley; C. A. Norman; et al. (1994). "ROSAT detection of diffuse hot gas in the edge-on galaxy NGC 4631". Astrophysical Journal. 439: 176–184. Bibcode:1995ApJ...439..176W. doi:10.1086/175162. hdl: 2060/19950011081 . S2CID   121407361.
  7. ↑ Q. D. Wang; S. Immler; R. Walterbos; J. T. Lauroesch; et al. (2001). "Chandra Detection of a Hot Gaseous Corona around the Edge-on Galaxy NGC 4631". Astrophysical Journal. 555 (2): L99–L102. arXiv: astro-ph/0105541 . Bibcode:2001ApJ...555L..99W. doi:10.1086/323179. S2CID   15558867.
  8. ↑ Transient Name Server entry for AT 2021biy. Retrieved 10 November 2023.
  9. ↑ H. Arp (1966). "Atlas of Peculiar Galaxies". Astrophysical Journal Supplement. 14: 1–20. Bibcode:1966ApJS...14....1A. doi:10.1086/190147.
  10. 1 2 R. B. Tully (1988). Nearby Galaxies Catalog. Cambridge: Cambridge University Press. ISBN   978-0-521-35299-4.
  11. ↑ 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.
  12. ↑ A. M. Garcia (1993). "General study of group membership. II - Determination of nearby groups". Astronomy and Astrophysics Supplement. 100: 47–90. Bibcode:1993A&AS..100...47G.
  13. 1 2 G. Giuricin; C. Marinoni; L. Ceriani; A. Pisani (2000). "Nearby Optical Galaxies: Selection of the Sample and Identification of Groups". Astrophysical Journal. 543 (1): 178–194. arXiv: astro-ph/0001140 . Bibcode:2000ApJ...543..178G. doi:10.1086/317070. S2CID   9618325.
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.