NGC 973

Last updated
NGC 973
NGC 973 PanSTARRS1 i.r.g.jpg
NGC 973 by Pan-STARRS
Observation data (J2000 epoch)
Constellation Triangulum
Right ascension 02h 34m 20.1s [1]
Declination +32° 30′ 20″ [1]
Redshift 0.016195 ± 0.000027 [1]
Helio radial velocity 4,855 ± 8 km/s [1]
Distance 195 ± 16 Mly (60.0 ± 4.8 Mpc) [1]
Apparent magnitude  (V)12.8 [2]
Characteristics
Type Sbc [1]
Apparent size  (V)4.03′ × 0.47′ [1]
Notable features Seyfert galaxy
Other designations
UGC 2048, CGCG 505-014, MCG +05-07-013, PGC 9795 [1]

NGC 973 is a giant [3] spiral galaxy located in the constellation Triangulum. It is located at a distance of circa 200 million light-years from Earth, which, given its apparent dimensions, means that NGC 973 is about 230,000 light years across. It was discovered by Lewis Swift on October 30, 1885. [4]

Contents

Characteristics

NGC 973 is seen edge-on, with an inclination of nearly 90°. [5] Its bulge is shaped like a box or peanut. The subtraction of axisymmetric components from the profile of the galaxy showed that its bulge has an X-like morphology, which indicates the presence of a bar. [6] A prominent dust lane runs across the galaxy. [7]

The galaxy kinematics revealed that the northeast side is the approaching one and the southwest is receding. The disk appears flat, without warps. The total hydrogen mass of the galaxy is estimated to be about 9×109  M☉ , [8] and the total dust mass is estimated to be 1.4×108 M☉, with clumpy distribution. [5] Faint emission from gas lying outside the plane of the galaxy was detected in H-alpha, correlated with the galactic disk and halo. [9]

The nucleus of NGC 973 appears to be active based on its emission. It is categorised as a type 2 Seyfert galaxy. [10] [11] The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole.

Nearby galaxies

NGC 973 is the largest galaxy in a galaxy group known as the NGC 973 group. [12] The NGC 973 group is one of the largest galaxy groups of the Perseus–Pisces Supercluster, [13] with at least 39 galaxies identified as its members. Other members of the group include NGC 917, NGC 931, NGC 940, NGC 969, NGC 974, NGC 978, NGC 987, NGC 983, NGC 1060, NGC 1066, NGC 1067, and UGC 2105. [14]

NGC 973 forms a pair with IC 1815, which lies 4.6 arcminutes to the south. [15] A small satellite was discovered in HI imaging near the northeast edge of the disk of NGC 973, with no optical counterpart. [8]

NGC 973 (DSS) NGC 0973 DSS.jpg
NGC 973 (DSS)

Related Research Articles

<span class="mw-page-title-main">NGC 5866</span> Galaxy in the constellation Draco

NGC 5866 is a relatively bright lenticular galaxy in the constellation Draco. NGC 5866 was most likely discovered by Pierre Méchain or Charles Messier in 1781, and independently found by William Herschel in 1788. Measured orbital velocities of its globular cluster system imply that dark matter makes up only 34±45% of the mass within 5 effective radii, a notable paucity.

<span class="mw-page-title-main">NGC 2787</span> Galaxy in the constellation Ursa Major

NGC 2787 is a barred lenticular galaxy approximately 24 million light-years away in the northern constellation of Ursa Major. It was discovered on December 3, 1788 by German-born astronomer William Herschel. J. L. E. Dreyer described it as, "bright, pretty large, a little extended 90°, much brighter middle, mottled but not resolved, very small (faint) star involved to the southeast". The visible galaxy has an angular size of 2′.5 × 1′.5 and an apparent visual magnitude of 11.8.

<span class="mw-page-title-main">Eyes Galaxies</span> Pair of galaxies in the constellation Virgo

The Eyes Galaxies are a pair of galaxies about 52 million light-years away in the constellation Virgo. The pair are members of the string of galaxies known as Markarian's Chain.

<span class="mw-page-title-main">NGC 7090</span> Spiral galaxy in the constellation Indus

NGC 7090 is a spiral galaxy in the southern constellation of Indus located about 31 million light-years away. English astronomer John Herschel first observed this galaxy on 4 October 1834.

<span class="mw-page-title-main">NGC 4698</span> Galaxy in the constellation Virgo

NGC 4698 is a barred spiral galaxy located around 55 million light years away from Earth in the constellation of Virgo. It belongs to the Virgo Cluster of galaxies and is positioned near the northeastern edge of this assemblage. The morphological classification of NGC 4698 in the De Vaucouleurs system is SA(s)ab, which indicates a purely spiral structure with moderate to tightly wound arms. It is inclined to the line of sight from the Earth by an angle of 53° along a position angle of 170°.

<span class="mw-page-title-main">NGC 5643</span> Galaxy in the constellation Lupus

NGC 5643 is an intermediate spiral galaxy in the constellation Lupus. Based on the tip of the red-giant branch distance indicator, it is located at a distance of about 40 million light-years. NGC 5643 has an active galactic nucleus and is a type II Seyfert galaxy.

<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 circa 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 3675</span> Galaxy in the constellation Ursa Major

NGC 3675 is a spiral galaxy located in the constellation Ursa Major. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 3675 is about 100,000 light years across. It was discovered by William Herschel in 1788.

<span class="mw-page-title-main">NGC 2336</span> Galaxy in the constellation Camelopardalis

NGC 2336 is a Barred spiral galaxy located in the constellation Camelopardalis. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 2336 is about 200,000 light years across. It was discovered by Wilhelm Tempel in 1876.

<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 1386</span> Galaxy in the constellation Eridanus

NGC 1386 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 53 million light years from Earth, which, given its apparent dimensions, means that NGC 1386 is about 50,000 light years across. It is a Seyfert galaxy, the only one in Fornax Cluster.

<span class="mw-page-title-main">NGC 5363</span> Galaxy in the constellation Virgo

NGC 5363 is a lenticular galaxy located in the constellation Virgo. It is located at a distance of circa 65 million light years from Earth, which, given its apparent dimensions, means that NGC 5363 is about 100,000 light years across. It was discovered by William Herschel on January 19, 1784. It is a member of the NGC 5364 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">NGC 765</span> Galaxy in the constellation Aries

NGC 765 is an intermediate spiral galaxy located in the constellation Aries. It is located at a distance of circa 220 million light years from Earth, which, given its apparent dimensions, means that NGC 765 is about 195,000 light years across. It was discovered by Albert Marth on October 8, 1864. The galaxy has an extensive hydrogen (HI) disk with low surface brightness, whose diameter is estimated to be 240 kpc.

<span class="mw-page-title-main">NGC 4294</span> Galaxy in the constellation Virgo

NGC 4294 is a barred spiral galaxy with flocculent spiral arms located about 55 million light-years away in the constellation Virgo. The galaxy was discovered by astronomer William Herschel on March 15, 1784 and is a member of the Virgo Cluster.

<span class="mw-page-title-main">NGC 4298</span> Galaxy in the constellation Coma Berenices

NGC 4298 is a flocculent spiral galaxy located about 53 million light-years away in the constellation Coma Berenices. The galaxy 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 4299</span> Spiral galaxy in the constellation Virgo

NGC 4299 is a featureless spiral galaxy located about 55 million light-years away in the constellation Virgo. It was discovered by astronomer William Herschel on March 15, 1784 and is a member of the Virgo Cluster.

<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 3175</span> Galaxy in the constellation Antlia

NGC 3175 is a spiral galaxy located in the far eastern part of the southern constellation of Antlia at an approximate distance of 54 million light-years. NGC 3175 was discovered on March 30, 1835 by English astronomer John Herschel, whose notes described it as, "considerably bright, large, much extended NE-SW, very gradually little brighter middle". This galaxy is the namesake of the NGC 3175 group of galaxies, which includes the spiral galaxy NGC 3137.

<span class="mw-page-title-main">NGC 959</span> Spiral galaxy in the northern constellation of Triangulum

NGC 959 is a spiral galaxy in the northern constellation of Triangulum. It was discovered on November 9, 1876, by French astronomer Édouard Stephan. This galaxy is located at a distance of 36 million light years and is receding with a heliocentric radial velocity of 596 km/s. It is a member of the NGC 1023 Group of galaxies.

<span class="mw-page-title-main">NGC 4324</span> Galaxy in the constellation of Virgo

NGC 4324 is a lenticular galaxy located about 85 million light-years away in the constellation Virgo. It was discovered by astronomer Heinrich d'Arrest on March 4, 1862. NGC 4324 has a stellar mass of 5.62 × 1010M☉, and a baryonic mass of 5.88 × 1010M☉. The galaxy's total mass is around 5.25 × 1011M☉. NGC 4324 is notable for having a ring of star formation surrounding its nucleus. It was considered a member of the Virgo II Groups until 1999, when its distance was recalculated and it was placed in the Virgo W Group.

References

  1. 1 2 3 4 5 6 7 8 "NASA/IPAC Extragalactic Database". Results for NGC 973. Retrieved 2019-01-18.
  2. ↑ "Revised NGC Data for NGC 973". spider.seds.org. Retrieved 25 November 2018.
  3. ↑ Saburova, A. S. (January 2018). "What made discy galaxies giant?". Monthly Notices of the Royal Astronomical Society. 473 (3): 3796–3809. arXiv: 1710.01341 . Bibcode:2018MNRAS.473.3796S. doi:10.1093/mnras/stx2583. S2CID   119425646.
  4. ↑ Seligman, Courtney. "NGC 973 (= PGC 9795)". Celestial Atlas. Retrieved 19 November 2018.
  5. 1 2 Xilouris, E. M.; Kylafis, N. D.; Papamastorakis, J.; Paleologou, E. V.; Haerendel, G. (1 September 1997). "The distribution of stars and dust in spiral galaxies: the edge-on spiral UGC 2048". Astronomy and Astrophysics. 325: 135–143. Bibcode:1997A&A...325..135X. ISSN   0004-6361.
  6. ↑ Patsis, P. A.; Xilouris, E. M. (11 March 2006). "Boxy/peanut 'bulges': comparing the structure of galaxies with the underlying families of periodic orbits". Monthly Notices of the Royal Astronomical Society. 366 (4): 1121–1125. arXiv: astro-ph/0512244 . Bibcode:2006MNRAS.366.1121P. doi:10.1111/j.1365-2966.2005.09922.x. S2CID   15496972.
  7. ↑ Guthrie, B. N. G. (1 May 1992). "Axial ratios of edge-on spirals". Astronomy and Astrophysics Supplement Series. 93: 255–270. Bibcode:1992A&AS...93..255G. ISSN   0365-0138.
  8. 1 2 Allaert, F.; Gentile, G.; Baes, M.; De Geyter, G.; Hughes, T. M.; Lewis, F.; Bianchi, S.; De Looze, I.; Fritz, J.; Holwerda, B. W.; Verstappen, J.; Viaene, S. (30 September 2015). "HERschel Observations of Edge-on Spirals (HEROES) II. Tilted-ring modelling of the atomic gas disks". Astronomy & Astrophysics. 582: A18. arXiv: 1507.03095 . Bibcode:2015A&A...582A..18A. doi: 10.1051/0004-6361/201526667 .
  9. ↑ Miller, Scott T.; Veilleux, Sylvain (October 2003). "Extraplanar Emission-Line Gas in Edge-On Spiral Galaxies. I. Deep Emission-Line Imaging". The Astrophysical Journal Supplement Series. 148 (2): 383–417. arXiv: astro-ph/0305026 . Bibcode:2003ApJS..148..383M. doi:10.1086/376604. S2CID   15897329.
  10. ↑ Hiroi, Kazuo; Ueda, Yoshihiro; et al. (1 August 2013). "The 37 Month MAXI/GSC Source Catalog of the High Galactic-Latitude Sky". The Astrophysical Journal Supplement Series. 207 (2): 36. arXiv: 1307.2455 . Bibcode:2013ApJS..207...36H. doi:10.1088/0067-0049/207/2/36. S2CID   119307506.
  11. ↑ Verstappen, J.; Fritz, J.; Baes, M.; Smith, M. W. L.; Allaert, F.; Bianchi, S.; Blommaert, J. A. D. L.; De Geyter, G.; De Looze, I.; Gentile, G.; Gordon, K. D.; Holwerda, B. W.; Viaene, S.; Xilouris, E. M. (24 July 2013). "HERschel Observations of Edge-on Spirals (HEROES) I. Far-infrared morphology and dust mass determination". Astronomy & Astrophysics. 556: A54. arXiv: 1305.3130 . Bibcode:2013A&A...556A..54V. doi: 10.1051/0004-6361/201220733 .
  12. ↑ Garcia, A. M. (1993). "General study of group membership. II - Determination of nearby groups". Astronomy and Astrophysics Supplement Series. 100 (1): 47–90. Bibcode:1993A&AS..100...47G. ISSN   0365-0138.
  13. ↑ "The Perseus-Pisces Supercluster". www.atlasoftheuniverse.com.
  14. ↑ Crook, Aidan C.; Huchra, John P.; Martimbeau, Nathalie; Masters, Karen L.; Jarrett, Tom; Macri, Lucas M. (October 2008). "Erratum: "Groups of Galaxies in the Two Micron All Sky Redshift Survey" (ApJ, 655, 790 [2007])". The Astrophysical Journal. 685 (2): 1320–1323. Bibcode:2008ApJ...685.1320C. doi: 10.1086/590385 .
  15. ↑ Nilson, P. (1973) Uppsala General Catalogue of Galaxies, Acta Universitatis Upsalienis, Nova Regiae Societatis Upsaliensis, Series V: A Vol. 1
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.