NGC 1667

Source: Wikipedia, the free encyclopedia.
148 ± 57 Mly (45.4 ± 17.4 Mpc)[1]
Apparent magnitude (V)12.1 [2]
Characteristics
TypeSAB(r)c [1]
Size~80,000 ly (24.6 kpc) (estimated)[1]
Apparent size (V)1.8′ × 1.4′[1]
Notable featuresSeyfert Galaxy
Other designations
IRAS 04461-0624, NGC 1689, MCG -01-13-013, PGC 16062[1]

NGC 1667, also catalogued as NGC 1689, is a

Lewis Swift on October 22, 1886.[3]

Characteristics

The galaxy has a small, bright nucleus with a

HII regions are visible across the arms and the inner ring.[8] The star formation rate of the galaxy is estimated to be 6.91 M☉ per year.[9]

Active nucleus

The nucleus of the galaxy has been found to be

emission lines.[10] The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole. The mass of the black hole in the centre of NGC 1667 is estimated to be 107.8 (60 million) M☉.[11]

Although the nucleus emits ultraviolet, radio waves and

X-rays at a low flux and with little short-term variability in 2004, but with a significant long-term drop in flux between 1977–78 and 2004.[14]

In the centre of the galaxy there are two peaks of CO(2-1) emission, two arcseconds across. The western peak lies at the kinematic centre of the galaxy. The inner two arcseconds of the galaxy are rotating at an angle of 150° with respect to the rest of the galaxy, indicating its core is counter-rotating, probably as a result of a merger or gas inflows.[15]

The spectrographic study of the nuclear region revealed a nuclear outflow and a gas disk which is twisted by the outflow in the inner arcsecond and gas inflowing from the spiral appear farther from the nucleus. The ionized gas mass outflow rate is estimated to be about 0.16 M☉ per year, while the gas inflow is about 2.8 M☉ per year about 800 parsec from the nucleus. However, most of the inflowing gas will probably not reach the nucleus and accumulate around it, leading to circumnuclear star formation.[16]

Supernova

One supernova has been observed in NGC 1667, SN 1986N. It was discovered on 11 December 1986, with an apparent magnitude of 15, by Carlton R. Pennypacker and others at the Leuschner Observatory. It was located 15" west and 7" south of the centre of the galaxy.[17] Based on its spectrum it was categorised as a type Ia supernova about 20 days post maximum light.[18]

Nearby galaxies

NGC 1667 is a member of the NGC 1667 Group, also known as LGG 118. Other members of the group includes the galaxies IC 387, NGC 1645, NGC 1659, MCG -1-13-12, IC 2101, and IC 2097.[19] NGC 1667 forms a non-interacting pair with NGC 1666, which lies 15 arcminutes away.[4]

References

  1. ^ a b c d e f g h i j k "NASA/IPAC Extragalactic Database". Results for NGC 1667. Retrieved 2016-01-18.
  2. ^ "Revised NGC Data for NGC 1667". spider.seds.org. Retrieved 30 March 2024.
  3. ^ Seligman, Courtney. "NGC 1667 (= PGC 16062)". Celestial Atlas. Retrieved 19 November 2018.
  4. ^
    Bibcode:1964rcbg.book.....D
    .
  5. doi:10.1086/300888
    .
  6. doi:10.1086/367817
    .
  7. ^ Sandage, A., Bedke, J. (1994), The Carnegie Atlas of Galaxies. Volume I, Carnegie Institution of Washington
  8. ^
    doi:10.1086/312951
    .
  9. doi:10.3847/0004-637X/822/1/45
    .
  10. doi:10.1086/313041
    .
  11. doi:10.3847/1538-4357/ad71c3
    .
  12. doi:10.1086/501529
    .
  13. ISSN 0004-6361
    .
  14. doi:10.1051/0004-6361:20053389
    .
  15. doi:10.1093/mnras/stz1244
    .
  16. doi:10.1093/mnras/stx018
    .
  17. ISSN 0081-0304
    .
  18. ISSN 0081-0304
    .
  19. ISSN 0365-0138
    .
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