NGC 4698

NGC 4698 is a barred spiral galaxy^[5] located around 55^[3] 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.^[4] The morphological classification of NGC 4698 in the De Vaucouleurs system is SA(s)ab,^[3] which indicates a purely spiral structure with moderate to tightly wound arms.^[7] It is inclined to the line of sight from the Earth by an angle of 53° along a position angle of 170°.^[8]

NGC 4698
NGC 4698 imaged with the 32-inch Schulman Telescope at Mount Lemmon Observatory
Observation data (J2000 epoch)
Constellation	Virgo
Right ascension	12h 34m 20.310s[1]
Declination	+08° 11′ 51.94″[1]
Heliocentric radial velocity	1,002[2] km/s
Distance	54.8 Mly (16.8 Mpc)[3]
Group or cluster	Virgo Cluster
Apparent magnitude (V)	10.6[4]
Apparent magnitude (B)	11.46[5]
Characteristics
Type	SA(s)ab[3]
Apparent size (V)	4′.0 × 2′.9[4]
Notable features	Seyfert-2 galaxy[6]
Other designations
PGC 43254, UGC 7970, VCC 2070

A unique feature of this galaxy is that the stars and dust of the nuclear disk are rotating in a direction that is aligned perpendicularly to the galactic disk. The bulge likewise appears elongated out of the galactic plane. This unusual alignment may have been the result of a past merger event.^[5]

NGC 4698 is classified as a Seyfert-2 galaxy with an active galactic nucleus, which displays a prominent emission of radio and X-ray energy from the core while showing narrow emission lines in the optical spectrum.^[6] The unified model of Seyfert galaxies proposes that the nucleus of a Seyfert 2 galaxy is obscured by a thick torus of gas and dust. However, the varying X-ray emission of the core of NGC 4698 shows little indication of being obstructed, suggesting instead that the source of the energy emission is generally unobscured but anemic in nature.^[9]

Gallery

• 
  NGC 4698 (SDSS DR14)
• 
  NGC 4698 (HST)
• 
  NGC 4698 by a Schulman telescope at Mt. Lemmon, AZ.

References

1. Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi:10.1086/498708. ISSN 0004-6256. S2CID 18913331.
2. Crook, Aidan C.; et al. (February 2007), "Groups of Galaxies in the Two Micron All Sky Redshift Survey", The Astrophysical Journal, 655 (2): 790–813, arXiv:astro-ph/0610732, Bibcode:2007ApJ...655..790C, doi:10.1086/510201, S2CID 11672751.
3. de Looze, Ilse; et al. (October 2011), "The reliability of [C II] as an indicator of the star formation rate", Monthly Notices of the Royal Astronomical Society, 416 (4): 2712–2724, arXiv:1106.1643, Bibcode:2011MNRAS.416.2712D, doi:10.1111/j.1365-2966.2011.19223.x.
4. Finlay, W. H. (2003), Concise Catalog of Deep-sky Objects: Astrophysical Information for 500 Galaxies, Clusters and Nebulae, Springer, p. 175, ISBN 978-1852336912.
5. Corsini, E. M.; et al. (June 2012), "Polar bulges and polar nuclear discs: the case of NGC 4698", Monthly Notices of the Royal Astronomical Society: Letters, 423 (1): L79–L83, arXiv:1204.2265, Bibcode:2012MNRAS.423L..79C, doi:10.1111/j.1745-3933.2012.01261.x, S2CID 119099390.
6. Georgantopoulos, I.; et al. (September 2003), "Chandra Observations of NGC 4698: A Seyfert 2 Galaxy with No Absorption", The Astrophysical Journal, 594 (2): 704–708, arXiv:astro-ph/0305488, Bibcode:2003ApJ...594..704G, doi:10.1086/377120, S2CID 13982986.
7. Buta, Ronald J.; et al. (2007), Atlas of Galaxies, Cambridge University Press, pp. 13–17, ISBN 978-0521820486.
8. Giovanardi, C.; et al. (March 1996), "Near-Infrared Low-Resolution Mapping of Early-Type Spirals", Astronomical Journal, 111 (2): 1086–1097, Bibcode:1996AJ....111.1086G, doi:10.1086/117854.
9. Tran, Hien D.; et al. (January 2011), "Indecent Exposure in Seyfert 2 Galaxies: A Close Look", The Astrophysical Journal Letters, 726 (2): L21, arXiv:1012.1865, Bibcode:2011ApJ...726L..21T, doi:10.1088/2041-8205/726/2/L21, S2CID 119190993.

External links

• Media related to NGC 4698 at Wikimedia Commons