NGC 3227

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NGC 3227
Hubble Space Telescope image of NGC 3226 and NGC 3227.jpg
Hubble Space Telescope image of NGC 3227 (left) and NGC 3226 (right)
Observation data (J2000 epoch)
Constellation Leo
Right ascension 10h 23m 30.6s [1]
Declination +19° 51′ 54″ [1]
Redshift 1157 ± 3 km/s [1]
Distance 77 ± 9 Mly (24 ± 3 Mpc) [2]
Apparent magnitude  (V)11.1 [1]
Characteristics
Type SAB(s) pec [1]
Apparent size  (V)5.4′ × 3.6′ [1]
Other designations
UGC 5620, [1] PGC 30445, [1] Arp 94 [1]

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 . [3] 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. [4]

Contents

Sir William Herschel already recognised them as a 'double nebula'[ citation needed ] and they were jointly listed as Holm 187 in the Catalogue of Double and Multiple Galaxies and as Arp 94 in the Atlas of Peculiar Galaxies. Amateur telescopes can discern them but require magnification of about 100 times. They are situated 50′ east of the well-known double star system Gamma Leonis (i.e. Algieba).

One supernova has been observed in NGC 3227: SN 1983U (type Ia, mag. 12) was discovered by Vladimir Pronik on 4 November 1983. [5] [6]

Nucleus

NGC 3227 contains a Seyfert nucleus, a type of active galactic nucleus (AGN). [7] Such Seyfert nuclei typically contain supermassive black holes. This object has an estimated mass of 1.4+1.0
−0.6×107  M☉ . [8]

As is typical of many AGN, the nucleus of NGC 3227 has been identified as a source of variable X-ray emission. [9] [10] [11] [12] [13] This variability occurs on time scales ranging from a few hours to a few months. [9] [11] [12] [13] The variability may be caused by variations in the density or ionization of gas and dust near the AGN that absorb the X-ray emission. [10] [11] [12] [13] A substantial amount of the X-ray-absorbing gas may lie within 0.4 parsec (1.3 light-years) of the nucleus. [13] An observed change in the shape of the X-ray spectrum in 2000 and 2001 suggests that some of the X-ray absorbing gas is located within 10–100 light-days of the nucleus. [14]

The luminosity of the nucleus reached a maximum in 1977 when evidence suggesting long-lived one-sided or two-sided gas streams was obtained. X-ray radiation of the central accretion disc is reprocessed in one to two days to be re-emitted in the optical spectrum. Infra-red light emission from the hot dust torus lags optical light emission from the nucleus by about 20 days in NGC 3227. The temperature of the dust torus is estimated at 1500 K to 1800 K in NGC 3227 and similar galaxies.

This galaxy was studied by the Multicolor Active Galactic Nuclei Monitoring 2m telescope. [15]

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 this luminosity is not produced by the 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 quasar host galaxies. 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">NGC 4395</span> Galaxy in the constellation Canes Venatici

NGC 4395 is a nearby low surface brightness spiral galaxy located about 14 million light-years from Earth in the constellation Canes Venatici. The nucleus of NGC 4395 is active and the galaxy is classified as a Seyfert Type I known for its very low-mass supermassive black hole.

<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. They were both discovered by German-British astronomer William Herschel on 15 February 1784. 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 5548</span> Type I Seyfert galaxy in the constellation Boötes

NGC 5548 is a Type I Seyfert galaxy with a bright, active nucleus. This activity is caused by matter flowing onto a 65 million solar mass (M☉) supermassive black hole at the core. Morphologically, this is an unbarred lenticular galaxy with tightly-wound spiral arms, while shell and tidal tail features suggest that it has undergone a cosmologically-recent merger or interaction event. NGC 5548 is approximately 245 million light years away and appears in the constellation Boötes. The apparent visual magnitude of NGC 5548 is approximately 13.3 in the V band.

<span class="mw-page-title-main">Ionization cone</span> Astronomical phenomenon

Ionization cones are cones of ionized material extending from active galactic nuclei, predominantly observed in type II Seyfert galaxies. They are detected through their emission of electromagnetic radiation in the visible and infrared parts of the spectrum. The main method of observation is through spectroscopy, using spectral line analysis to measure the shape of the ionized region and the condition of the material such as temperature, density, composition, and degree of ionization.

<span class="mw-page-title-main">NGC 3783</span> Galaxy in the constellation Centaurus

NGC 3783 is a barred spiral galaxy located about 135 million light years away in the constellation Centaurus. It is inclined by an angle of 23° to the line of sight from the Earth along a position angle of about 163°. The morphological classification of SBa indicates a bar structure across the center (B) and tightly-wound spiral arms (a). Although not shown by this classification, observers note the galaxy has a luminous inner ring surrounding the bar structure. The bright compact nucleus is active and categorized as a Seyfert 1 type. This nucleus is a strong source of X-ray emission and undergoes variations in emission across the electromagnetic spectrum.

<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 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 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 4278</span> Galaxy in the constellation Coma Berenices

NGC 4278 is an elliptical galaxy located in the constellation Coma Berenices. It is located at a distance of circa 55 million light years from Earth, which, given its apparent dimensions, means that NGC 4278 is about 65,000 light years across. It was discovered by William Herschel on March 13, 1785. NGC 4278 is part of the Herschel 400 Catalogue and can be found about one and 3/4 of a degree northwest of Gamma Comae Berenices even with a small telescope.

<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 7592</span> Interacting galaxy system in the constellation Aquarius

NGC 7592 is an interacting galaxy system located 300 million light years away in the constellation Aquarius. It was discovered by William Herschel on September 20, 1784. The total infrared luminosity is 1011.33 L☉, and thus it is categorised as a luminous infrared galaxy. One of the galaxies hosts a type 2 Seyfert nucleus.

<span class="mw-page-title-main">NGC 2617</span> Galaxy in the constellation Hydra

NGC 2617 is a Seyfert galaxy in the equatorial constellation of Hydra. It was discovered on February 12, 1885, by French astronomer Édouard Stephan. In 1888, Danish astronomer J. L. E. Dreyer described it as "extremely faint, very small, 2 very faint stars involved". It is located at an estimated distance of 202 million light years. In the infrared, the galaxy has an angular size of 0.693 by 0.652 arcminutes.

<span class="mw-page-title-main">NGC 7172</span> Galaxy in the constellation of Piscis Austrinus

NGC 7172 is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 110 million light years from Earth, which, given its apparent dimensions, means that NGC 7172 is about 100,000 light years across. It was discovered by John Herschel on September 23, 1834.

<span class="mw-page-title-main">NGC 3516</span> Galaxy in the constellation of Ursa Major

NGC 3516 is a barred lenticular galaxy in the constellation of Ursa Major. NGC 3516 is located about 150 million light years away from Earth, which means, given its apparent dimensions, that NGC 3516 is approximately 100,000 light years across. It was discovered by William Herschel on April 3, 1785.

<span class="mw-page-title-main">NGC 4593</span> Galaxy in the constellation of Virgo

NGC 4593 is a barred spiral galaxy located in the constellation Virgo. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 4593 is about 125,000 light years across. It was discovered by William Herschel on April 17, 1784. It is a Seyfert galaxy.

<span class="mw-page-title-main">Markarian 590</span> Galaxy in the constellation of Cetus

Markarian 590, also known as NGC 863, NGC 866, and NGC 885, is a spiral galaxy located in the constellation Cetus. It is located at a distance of about 300 million light years from Earth, which, given its apparent dimensions, means that NGC 863 is about 110,000 light years across. It is a change looking Seyfert galaxy.

<span class="mw-page-title-main">NGC 4253</span> Galaxy in the constellation of Coma Berenices

NGC 4253 is a barred spiral galaxy located in the constellation Coma Berenices. It is located at a distance of about 185 million light years from Earth, which, given its apparent dimensions, means that NGC 4253 is about 65,000 light years across. It was discovered by William Herschel on February 3, 1788. It is a Seyfert galaxy.

<span class="mw-page-title-main">NGC 2110</span> Galaxy in the constellation Orion

NGC 2110 is a lenticular galaxy located in the constellation Orion. It is located at a distance of about 120 million light years from Earth, which, given its apparent dimensions, means that NGC 2110 is about 90,000 light years across. It was discovered by William Herschel on October 5, 1785. It is a Seyfert galaxy.

References

  1. 1 2 3 4 5 6 7 8 9 "NASA/IPAC Extragalactic Database". Results for NGC 3227. Retrieved 2006-10-12.
  2. ↑ J. L. Tonry; A. Dressler; J. P. Blakeslee; E. A. Ajhar; et al. (2001). "The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances". Astrophysical Journal. 546 (2): 681–693. arXiv: astro-ph/0011223 . Bibcode:2001ApJ...546..681T. doi:10.1086/318301. S2CID   17628238.
  3. ↑ H. Arp (1966). "Atlas of Peculiar Galaxies". Astrophysical Journal Supplement. 14: 1–20. Bibcode:1966ApJS...14....1A. doi:10.1086/190147.
  4. ↑ "The Leo III Groups". Atlas of the Universe. Archived from the original on July 22, 2012. Retrieved 2010-11-27.
  5. ↑ Aksenov, E. P.; Pronik, V. (1983). "Supernova in NGC 3227". International Astronomical Union Circular (3887): 1. Bibcode:1983IAUC.3887....1A.
  6. ↑ "SN 1983U". Transient Name Server. IAU . Retrieved 5 December 2024.
  7. ↑ L. C. Ho; A. V. Filippenko; W. L. W. Sargent (1997). "A Search for "Dwarf" Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies". Astrophysical Journal Supplement. 112 (2): 315–390. arXiv: astro-ph/9704107 . Bibcode:1997ApJS..112..315H. doi:10.1086/313041. S2CID   17086638.
  8. ↑ Graham, Alister W. (November 2008), "Populating the Galaxy Velocity Dispersion - Supermassive Black Hole Mass Diagram: A Catalogue of (Mbh, σ) Values", Publications of the Astronomical Society of Australia, 25 (4): 167–175, arXiv: 0807.2549 , Bibcode:2008PASA...25..167G, doi:10.1071/AS08013, S2CID   89905.
  9. 1 2 A. F. Tennant; R. F. Mushotzky (1983). "The absence of rapid X-ray variability in active galaxies". Astrophysical Journal. 264: 92–104. Bibcode:1983ApJ...264...92T. doi:10.1086/160576. hdl: 2060/19820022328 . S2CID   117087588.
  10. 1 2 T. J. Turner; K. A. Pounds (1989). "The EXOSAT spectral survey of AGN". Monthly Notices of the Royal Astronomical Society . 240 (4): 833–880. Bibcode:1989MNRAS.240..833T. doi: 10.1093/mnras/240.4.833 .
  11. 1 2 3 A. Ptak; T. Yaqoob; P. J. Serlemitsos; R. Mushotzky; et al. (1994). "Rapid X-ray spectral variability in NGC 3227" (PDF). Astrophysical Journal. 436: L31–L34. Bibcode:1994ApJ...436L..31P. doi:10.1086/187626.
  12. 1 2 3 S. Komossa; H. Fink (1997). "Evidence for a dusty warm absorber in NGC 3227?". Astronomy and Astrophysics. 327: 483–492. arXiv: astro-ph/9707003 . Bibcode:1997A&A...327..483K.
  13. 1 2 3 4 P. Gondoin; A. Orr; D. Lumb; H. Siddiqui (2003). "XMM-Newton observations of the Seyfert 1 galaxy NGC 3227". Astronomy and Astrophysics. 397 (3): 883–890. Bibcode:2003A&A...397..883G. doi: 10.1051/0004-6361:20021574 .
  14. ↑ G. Lamer; P. Uttley; I. M. McHardy (2003). "An absorption event in the X-ray light curve of NGC 3227". Monthly Notices of the Royal Astronomical Society. 342 (3): L41–L45. arXiv: astro-ph/0305130 . Bibcode:2003MNRAS.342L..41L. doi: 10.1046/j.1365-8711.2003.06759.x . S2CID   16031703.
  15. ↑ http://www.journals.uchicago.edu/doi/abs/10.1086/499326 The Astrophysical Journal, 639:46–63, 2006 March 1 "Reverberation Measurements of the Inner Radius of the Dust Torus in Nearby Seyfert 1 Galaxies"
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