NGC 1672

Last updated
NGC 1672
NGC1672 - Iotw2205a.jpg
The galaxy photographed with the Víctor M. Blanco Telescope
Observation data (J2000 epoch)
Constellation Dorado
Right ascension 04h 45m 42.500s [1]
Declination −59° 14 49.85 [1]
Redshift 1331 ± 3 km/s [1]
Distance 51.7 ± 3.0  Mly (15.86 ± 0.92  Mpc) [2]
Apparent magnitude  (V)10.3 [1]
Characteristics
Type (R')SB(r)bc [1]
Apparent size  (V)6.6 × 5.5 [1]
Other designations
PGC 15941 [1]

NGC 1672 is a barred spiral galaxy located in the constellation Dorado. It was discovered by the astronomer James Dunlop on November 5, 1826. [3] It was originally unclear whether it was a member of the Dorado Group, with some sources [4] finding it to be a member and other sources [5] rejecting its membership. However, recent tip of the red-giant branch (TRGB) measurements indicate that NGC 1672 is located at the same distance as other members, suggesting it is indeed a member of the Dorado Group. [2]

Contents

NGC 1672 has a large bar which is estimated to measure around 20 kpc. [6] It has very strong radio emissions emanating from its nucleus, bar, and the inner portion of the spiral arm region. [6] The nucleus is Seyfert type II and is engulfed by a starburst region. [6] The strongest polarized emissions come from the northeastern region which is upstream from its dust lanes. [6] Magnetic field lines are at large angles with respect to the bar and turn smoothly to the center. [6]

Two supernovae have been observed in NGC 1672: SN 2017gax (type Ib/c, mag. 14.1) [7] and SN 2022aau (type II, mag. 16.3). [8]

General structure

The center of the galaxy contains a high surface brightness bar, and four filament-like spiral arms extend outward from the ends of this bar. The spiral arms are asymmetric; one of the arms in the northeast part of the disk is significantly brighter than its counterpart on the other side. The spiral arms also contain numerous star formation regions, some of which may be as large as 4″. [9]

Nucleus

The classification of the nucleus of NGC 1672 is uncertain. Most galaxies may be classified by their spectra as having one of three different types of nuclei: [10]

NGC 1672, however, is one of several nearby galaxies that does not fit into this classification scheme, as its spectrum appears intermediary between these three classes of objects. [10] It may in fact contain both nuclear star formation regions and an AGN. In some wave bands (such as in ultraviolet light), the star formation regions are the primary source of emission. [11]

See also

Related Research Articles

An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that the luminosity is not produced by stars. Such excess, non-stellar emissions have been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an active galaxy. The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy.

<span class="mw-page-title-main">Seyfert galaxy</span> Class of active galaxies with very bright nuclei

Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.

<span class="mw-page-title-main">Messier 77</span> Barred spiral galaxy in the constellation Cetus

Messier 77 (M77), also known as NGC 1068 or the Squid Galaxy, is a barred spiral galaxy in the constellation Cetus. It is about 47 million light-years (14 Mpc) away from Earth. Messier 77 was discovered by Pierre Méchain in 1780, who originally described it as a nebula. Méchain then communicated his discovery to Charles Messier, who subsequently listed the object in his catalog. Both Messier and William Herschel described this galaxy as a star cluster. Today, however, the object is known to be a galaxy.

<span class="mw-page-title-main">NGC 1097</span> Galaxy in the constellation Fornax

NGC 1097 is a barred spiral galaxy about 45 million light years away in the constellation Fornax. It was discovered by William Herschel on 9 October 1790. It is a severely interacting galaxy with obvious tidal debris and distortions caused by interaction with the companion galaxy NGC 1097A.

<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 3226</span> Dwarf elliptical galaxy in the constellation Leo

NGC 3226 is a dwarf elliptical galaxy that is interacting with the spiral galaxy NGC 3227. 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">Low-ionization nuclear emission-line region</span> Type of galactic nucleus

A low-ionization nuclear emission-line region (LINER) is a type of galactic nucleus that is defined by its spectral line emission. The spectra typically include line emission from weakly ionized or neutral atoms, such as O, O+, N+, and S+. Conversely, the spectral line emission from strongly ionized atoms, such as O++, Ne++, and He+, is relatively weak. The class of galactic nuclei was first identified by Timothy Heckman in the third of a series of papers on the spectra of galactic nuclei that were published in 1980.

<span class="mw-page-title-main">NGC 7319</span> Galaxy in the constellation Pegasus

NGC 7319 is a highly distorted barred spiral galaxy that is a member of the compact Stephan's Quintet group located in the constellation Pegasus, some 311 megalight-years distant from the Milky Way. The galaxy's arms, dust and gas have been highly disturbed as a result of the interaction with the other members of the Quintet. Nearly all of the neutral hydrogen has been stripped from this galaxy, most likely as a result of a collision with NGC 7320c some 100 million years ago. A pair of long, parallel tidal tails extend southward from NGC 7319 in the direction of NGC 7320c, and is undergoing star formation.

<span class="mw-page-title-main">NGC 1433</span> Galaxy in the constellation Horologium

NGC 1433 is a barred spiral galaxy with a double ring structure located in the constellation of Horologium. It is at a distance of 46 million light-years from Earth. It is a Seyfert galaxy with an active galactic nucleus. The central region of the galaxy displays intense star formation activity, with an irregular star-forming ring of 5″ radius and weak radio wave emission. Star formation is also noticeable in the spiral arms but not the bar of the galaxy. NGC 1433 is being studied as part of a survey of 50 nearby galaxies known as the Legacy ExtraGalactic UV Survey (LEGUS). A jet of material flowing away from the central black hole of the galaxy extending for only 150 light-years has been found. It is the smallest molecular outflow ever observed in a galaxy beyond our own.

<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 3081</span> Galaxy in the constellation Hydra

NGC 3081 is a barred lenticular ring galaxy in the constellation of Hydra. NGC 3081 is located about 85 million light-years away from Earth, which means, given its apparent dimensions, that NGC 3081 is approximately 60,000 light-years across. It is a type II Seyfert galaxy, characterised by its bright nucleus. It was discovered by William Herschel on 21 December 1786.

<span class="mw-page-title-main">NGC 7469</span> Galaxy located in the constellation Pegasus

NGC 7469 is an intermediate spiral galaxy in the constellation of Pegasus. NGC 7469 is located about 200 million light-years away from Earth, which means, given its apparent dimensions, that NGC 7469 is approximately 90,000 light-years across. It was discovered by William Herschel on November 12, 1784.

<span class="mw-page-title-main">NGC 3367</span> Spiral galaxy in the constellation Leo

NGC 3367 is a barred spiral galaxy located in the constellation Leo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 3367 is about 85,000 light years across. It was discovered by William Herschel on March 19, 1784.

<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 7674</span> Galaxy located in the constellation Pegasus

NGC 7674 is a spiral galaxy located in the constellation Pegasus. It is located at a distance of circa 350 million light years from Earth, which, given its apparent dimensions, means that NGC 7674 is about 125,000 light years across. It was discovered by John Herschel on August 16, 1830.

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

NGC 6951 is a barred spiral galaxy located in the 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 2273</span> Galaxy in the constellation Lynx

NGC 2273 is a barred spiral galaxy located in the constellation Lynx. It is located at a distance of circa 95 million light years from Earth, which, given its apparent dimensions, means that NGC 2273 is about 100,000 light years across. It was discovered by Nils Dunér on September 15, 1867.

<span class="mw-page-title-main">NGC 5728</span> Spiral galaxy in the constellation Libra

NGC 5728 is an active barred spiral galaxy located 146 million light years away in the southern constellation of Libra. It was discovered on May 7, 1787 by William Herschel. The designation comes from the New General Catalogue of J. L. E. Dreyer, published in 1888. It has an apparent visual magnitude of 13.40 and spans an angle of 3.4 arcminutes. The galaxy shows a red shift of 0.00935 and has a heliocentric radial velocity of 2,803 km/s. It has an estimated mass of 72 billion times the mass of the Sun and stretches around 30 kpc across.

<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.

<span class="mw-page-title-main">NGC 5135</span>

NGC 5135 is a barred spiral galaxy located in the constellation Hydra. It is located at a distance of about 200 million light years from Earth. It was discovered by John Herschel on May 8, 1834. It is a Seyfert galaxy.

References

  1. 1 2 3 4 5 6 7 "Results for object NGC 1672 (NGC 1672)". NASA/IPAC Extragalactic Database. California Institute of Technology. Retrieved 2021-04-29.
  2. 1 2 Tikhonov, N. A.; Galazutdinova, O. A. (2020). "Distance to the Dorado Group". Astrophysical Bulletin. 75 (4): 384–393. arXiv: 2009.04090 . Bibcode:2020AstBu..75..384T. doi:10.1134/S199034132004015X. S2CID   221556782.
  3. Seligman, Courtney. "New General Catalogue objects: NGC 1650 - 1699". cseligman.com. Retrieved 2021-04-29.
  4. Huchra, J. P.; Geller, M. J. (June 15, 1982). "Groups of galaxies. I - Nearby groups". Astrophysical Journal. 257 (Part 1): 423–437. Bibcode:1982ApJ...257..423H. doi:10.1086/160000.
  5. Maia, M. A. G.; da Costa, L. N.; Latham, David W. (April 1989). "A catalog of southern groups of galaxies". Astrophysical Journal Supplement Series. 69: 809–829. Bibcode:1989ApJS...69..809M. doi: 10.1086/191328 . ISSN   0067-0049.
  6. 1 2 3 4 5 Beck, R.; Shoutenkov, V.; Ehle, M.; Harnett, J. I.; et al. (August 2002). "Magnetic fields in barred galaxies. I. The atlas". Astronomy and Astrophysics. 391 (1): 83–102. arXiv: astro-ph/0207201 . Bibcode:2002A&A...391...83B. doi:10.1051/0004-6361:20020642. S2CID   14749261.
  7. Transient Name Server entry for SN 2017gax. Retrieved 24 March 2023.
  8. Transient Name Server entry for SN 2022aau. Retrieved 24 March 2023.
  9. A. Sandage; J. Bedke (1994). Carnegie Atlas of Galaxies. Washington, D.C.: Carnegie Institution of Washington. ISBN   978-0-87279-667-6.
  10. 1 2 P. Veron; A. C. Goncalves; M. P. Veron-Cetty (1997). "AGNs with composite spectra". Astronomy and Astrophysics. 319: 52–66. Bibcode:1997A&A...319...52V.
  11. A. L. Kinney; R. C. Bohlin; D. Calzetti; N. Panagia; et al. (1993). "An atlas of ultraviolet spectra of star-forming galaxies". Astrophysical Journal Supplement Series. 86: 5–93. Bibcode:1993ApJS...86....5K. doi: 10.1086/191771 .