NGC 7213

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NGC 7213
NGC 7213 hst 09107 R814B555.png
NGC 7213 by the Hubble Space Telescope
Observation data (J2000 epoch)
Constellation Grus
Right ascension 22h 09m 16.3s [1]
Declination −47° 09′ 59″ [1]
Redshift 0.005839 +/- 0.000019 [1]
Heliocentric radial velocity 1,750 ± 6 km/s [1]
Distance 72 Mly (22 Mpc) [1]
Apparent magnitude  (V)10.1
Characteristics
Type SA(s)0^0 [1]
Apparent size  (V)3.1′ × 2.8′ [1]
Notable featuresSeyfert galaxy, LINER
Other designations
ESO 288- G043, AM 2206-472, PGC 68165 [1]

NGC 7213 is a lenticular galaxy located in the constellation Grus. It is located at a distance of circa 70 million light-years from Earth, which, given its apparent dimensions, means that NGC 7213 is about 75,000 light-years across. [1] It was discovered by John Herschel on September 30, 1834. [2] It is an active galaxy with characteristics between a type I Seyfert galaxy and LINER.

Contents

Characteristics

The nucleus of NGC 7213 features activity and belongs to the low-luminosity active galactic nuclei (LLAGN). The optical spectrum features broad H-alpha lines and has similar characteristics to a type I Seyfert galaxy, however it is considerably less luminous than other similar galaxies. [3] It also features [Ne V] λ3426, He II λ4686, [O II] λ3726, 3729, 7319, 7330, [O III] λ4363, 4959, and 5007 emission lines. However the intensity ratios of many of these lines is similar to a LINER. [4] Observed in radio waves, NGC 7213 looks like a point-like source that could feature two jets that bend between one 1 arcsec (150 pc) and 10 arcsec (1.5 kpc). It is categorised as a radio-intermediate galaxy, lying between radio-quiet and radio-loud sources. [5] The source of activity in the AGNs is a supermassive black hole (SMBH) lying at the centre of the galaxy. The mass of the SMBH at the centre of NGC 7213 is estimated to be between 8×107  M☉ [6] and 9.6+6.1
−4.1×107 M☉ based on the mean velocity dispersion [5] or (3-47) × 106 (106.83+0.84
−0.33) M☉ based on the polarization of broad Hα emission. [7]

NGC 7213 has been found to be a low-luminosity X-ray source. The 2-10 keV spectrum of NGC 7213 resembles the spectrum of Seyfert I galaxies, but also contains significant emission lines from FeXXV and FeXXVI, which are observed in LINERs and are not present in most classical Seyfert galaxies. Also, the soft X-ray spectrum of NGC 7213 features collisionally ionized thermal plasma, one more characteristic of LINERs. In addition, there is no X-ray emission detected that can be attributed to an accretion disk. [8] Observations by NuSTAR at 3-79 keV showed no evidence for a Compton-reflected continuum. The observations suggest that the accretion disc is truncated in the inner region, with the black hole being fed via radiative-inefficient accretion flows. [9]

The X-ray flux of NGC 7213 is fluctuating, presenting a sharp flare, larger than the others, in the 1980s with the flux reducing steadily after for more than 20 years. This flare showed a fast-rise-exponential-decay pattern and has been suggested to be caused by the tidal disruption of a main sequence star by the black hole at the centre of NGC 7213. [10] Smaller scale flares are also observed. The emission variability is also observed in other wavelengths with a time lag. The lag is 24 ± 12 days for 8.4 GHz radio and 40 ± 13 days for the 4.8 GHz radio. [11]

Surrounding the nucleus is a ring of starforming regions, lying at a radius of circa 20 arcseconds. Closer to the nucleus can be observed a dusty spiral pattern, with two arms, with the northwest arm being on the near side of the galaxy, and the southeast one to the far side. The ionised gas inflow rate towards the nucleus is estimated to be 0.2 M☉ per year. [6] Although NGC 7213 appears undisturbed in visible light, it shows signs of having undergone a collision or merger when viewed at longer wavelengths, with disturbed patterns of ionized hydrogen including a filament of gas around 64,000 light-years long, itself being part of a larger HI tidal tail southwest of the nucleus. [12]

Nearby galaxies

NGC 7213 is the foremost galaxy in a galaxy group known as the NGC 7213 group. Other members of the group include IC 5170, IC 5181, NGC 7232, and NGC 7233. A bit further away lies the NGC 7144 group, which includes NGC 7144, NGC 7145, NGC 7151, and NGC 7155. [13] These galaxies group are part of the Pavo-Indus cloud and the Grus cloud, which lie between the Local Supercluster and Pavo–Indus Supercluster. [14]

See also

Other Seyfert galaxies include:

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 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">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 4639</span> Galaxy in the constellation Virgo

NGC 4639 is a barred spiral galaxy located in the equatorial constellation of Virgo. It was discovered by German-born astronomer William Herschel on April 12, 1784. John L. E. Dreyer described it as "pretty bright, small, extended, mottled but not resolved, 12th magnitude star 1 arcmin to southeast". This is a relatively nearby galaxy, lying approximately 72 million light-years away from the Milky Way. It is a companion to NGC 4654, and the two appear to have interacted roughly 500 million years ago. NGC 4639 is a member of the Virgo Cluster.

<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 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 4111</span> Galaxy in constellation Canes Venatici

NGC 4111 is a lenticular galaxy in the constellation Canes Venatici. It is located at a distance of circa 50 million light-years from Earth, which, given its apparent dimensions, means that NGC 4111 is about 55,000 light-years across. It was discovered by William Herschel in 1788. NGC 4111 possesses both thin and thick discs.

<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 985</span> Ring galaxy in the constellation Cetus

NGC 985 is a ring galaxy in the constellation of Cetus. It is located about 550 million light years away from Earth, which means, given its apparent dimensions, that NGC 985 is approximately 160,000 light years across. It was discovered by Francis Leavenworth in 1886. It is a type 1 Seyfert galaxy.

<span class="mw-page-title-main">NGC 3489</span> Galaxy in the constellation Leo

NGC 3489 is a lenticular galaxy located in the constellation Leo. It is located at a distance of about 30 million light years from Earth, which, given its apparent dimensions, means that NGC 3489 is about 30,000 light years across. It was discovered by William Herschel on April 8, 1784. NGC 3489 is a member of the Leo Group.

<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">IC 1459</span> Elliptical galaxy in the constellation of Grus

IC 1459 is an elliptical galaxy located in the constellation Grus. It is located at a distance of circa 85 million light-years from Earth, which, given its apparent dimensions, means that IC 1459 is about 130,000 light-years across. It was discovered by Edward Emerson Barnard in 1892.

<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 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 5506</span> Galaxy in the constellation of Virgo

NGC 5506 is a spiral galaxy located in the constellation Virgo. It is located at a distance of about 75 million light years from Earth, which, given its apparent dimensions, means that NGC 5506 is about 80,000 light years across. It was discovered by William Herschel on April 15, 1787. 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.

References

  1. 1 2 3 4 5 6 7 8 9 "NASA/IPAC Extragalactic Database". Results for NGC 7213. Retrieved 2016-01-18.
  2. ↑ Seligman, Courtney. "NGC 7213 (= PGC 68165)". Celestial Atlas. Retrieved 19 November 2018.
  3. ↑ Phillips, M. M. (February 1979). "Optical Spectrophotometry of the Suspected X-Ray Galaxies NGC 6221 and NGC 7213". The Astrophysical Journal. 227: L121. Bibcode:1979ApJ...227L.121P. doi: 10.1086/182881 .
  4. ↑ Filippenko, A. V.; Halpern, J. P. (October 1984). "NGC 7213 - A key to the nature of liners?". The Astrophysical Journal. 285: 458. Bibcode:1984ApJ...285..458F. doi:10.1086/162521.
  5. 1 2 Blank, D. L.; Harnett, J. I.; Jones, P. A. (January 2005). "An 8.4-GHz Long Baseline Array observation of the unusual Seyfert galaxy NGC 7213". Monthly Notices of the Royal Astronomical Society. 356 (2): 734–736. Bibcode:2005MNRAS.356..734B. doi: 10.1111/j.1365-2966.2004.08506.x . hdl: 10453/357 .
  6. 1 2 Schnorr-Müller, Allan; Storchi-Bergmann, Thaisa; Nagar, Neil M.; Ferrari, Fabricio (11 March 2014). "Gas inflows towards the nucleus of the active galaxy NGC 7213". Monthly Notices of the Royal Astronomical Society. 438 (4): 3322–3331. arXiv: 1401.5650 . Bibcode:2014MNRAS.438.3322S. doi: 10.1093/mnras/stt2440 .
  7. ↑ Piotrovich, M. Yu.; Gnedin, Yu. N.; Silant'ev, N. A.; Natsvlishvili, T. M.; Buliga, S. D. (30 September 2015). "A polarimetric method for measuring black hole masses in Active Galactic Nuclei". Monthly Notices of the Royal Astronomical Society. 454 (1): 1157–1160. arXiv: 1509.01028 . Bibcode:2015MNRAS.454.1157P. doi: 10.1093/mnras/stv2047 .
  8. ↑ Starling, R. L. C.; Page, M. J.; Branduardi-Raymont, G.; Breeveld, A. A.; Soria, R.; Wu, K. (January 2005). "The X-ray spectrum of NGC 7213 and the Seyfert-LINER connection". Monthly Notices of the Royal Astronomical Society. 356 (2): 727–733. arXiv: astro-ph/0410333 . Bibcode:2005MNRAS.356..727S. doi: 10.1111/j.1365-2966.2004.08493.x . S2CID   9379160.
  9. ↑ Ursini, F.; Marinucci, A.; Matt, G.; Bianchi, S.; Tortosa, A.; Stern, D.; Arévalo, P.; Ballantyne, D. R.; Bauer, F. E.; Fabian, A. C.; Harrison, F. A.; Lohfink, A. M.; Reynolds, C. S.; Walton, D. J. (3 August 2015). "The NuSTAR X-ray spectrum of the low-luminosity active galactic nucleus in NGC 7213". Monthly Notices of the Royal Astronomical Society. 452 (3): 3266–3272. arXiv: 1507.01775 . Bibcode:2015MNRAS.452.3266U. doi: 10.1093/mnras/stv1527 .
  10. ↑ Yan, Zhen; Xie, Fu-Guo (March 2018). "A decades-long fast-rise-exponential-decay flare in low-luminosity AGN NGC 7213". Monthly Notices of the Royal Astronomical Society. 475 (1): 1190–1197. arXiv: 1712.05272 . Bibcode:2018MNRAS.475.1190Y. doi: 10.1093/mnras/stx3259 .
  11. ↑ Bell, M. E.; Tzioumis, T.; Uttley, P.; Fender, R. P.; Arévalo, P.; Breedt, E.; McHardy, I.; Calvelo, D. E.; Jamil, O.; Körding, E. (11 February 2011). "X-ray and radio variability in the low-luminosity active galactic nucleus NGC 7213". Monthly Notices of the Royal Astronomical Society. 411 (1): 402–410. arXiv: 1009.2430 . Bibcode:2011MNRAS.411..402B. doi: 10.1111/j.1365-2966.2010.17692.x . S2CID   119175096.
  12. ↑ Hameed, Salman; Blank, David L.; Young, Lisa M.; Devereux, Nick (10 January 2001). "The Discovery of a Giant Hα Filament in NGC 7213". The Astrophysical Journal. 546 (2): L97–L100. arXiv: astro-ph/0011208 . Bibcode:2001ApJ...546L..97H. doi:10.1086/318865. S2CID   2657286.
  13. ↑ Makarov, Dmitry; Karachentsev, Igor (21 April 2011). "Galaxy groups and clouds in the local (z~ 0.01) Universe". Monthly Notices of the Royal Astronomical Society. 412 (4): 2498–2520. arXiv: 1011.6277 . Bibcode:2011MNRAS.412.2498M. doi: 10.1111/j.1365-2966.2010.18071.x . S2CID   119194025.
  14. ↑ Fouque, P.; Proust, D.; Quintana, H.; Ramirez, A.; Proust, D.; Quintana, H.; Ramirez, A. (1993). "Dynamics of the Pavo-Indus and Grus Clouds of Galaxies". Astronomy and Astrophysics Supplement Series. 100 (3): 493–500. Bibcode:1993A&AS..100..493F.{{cite journal}}: CS1 maint: multiple names: authors list (link)


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