NGC 4698

NGC 4698
A spiral galaxy viewed at an angle, with a bright central bulge and winding spiral arms. The arms form a ring around the galaxy, without appearing to reach its centre. Prominent red-brown dust lanes weave through the arms, which are also dotted with bright blue and reddish regions of star formation. The galaxy is set against a dark background scattered with stars and faint distant galaxies.
NGC 4698 imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
ConstellationVirgo
Right ascension12h 48m 22.9151s
Declination+08° 29′ 14.514″
Redshift0.003366±0.00000200
Heliocentric radial velocity1,002 km/s
Distance73.22 ± 4.17 Mly (22.448 ± 1.279 Mpc)
Group or clusterVirgo Cluster
Apparent magnitude (V)10.6
Apparent magnitude (B)11.46
Characteristics
TypeSA(s)ab
Apparent size (V)4′.0 × 2′.9
Notable featuresSeyfert-2 galaxy
Other designations
VCC 2070, IRAS 12458+0845, 2MASX J12482293+0829140, UGC 7970, MCG +02-33-024, PGC 43254, CGCG 071-045

NGC 4698 is a barred spiral galaxy in the constellation Virgo. It belongs to the Virgo Cluster of galaxies and is positioned near the northeastern edge of this assemblage. Its velocity with respect to the cosmic microwave background is 1,335±23 km/s, which corresponds to a Hubble distance of 64.2 ± 4.6 Mly (19.69 ± 1.42 Mpc). However, 28 non-redshift measurements give a farther mean distance of 73.22 ± 4.17 Mly (22.448 ± 1.279 Mpc). It was discovered by German-British astronomer William Herschel on 18 January 1784.

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°.

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.

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. 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.

References

  1. 1 2 3 4 5 "Results for object NGC 4698". NASA/IPAC Extragalactic Database. NASA and Caltech. Retrieved 16 September 2026.
  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. 1 2 "Distance Results for NGC 4698". NASA/IPAC Extragalactic Database. NASA. Retrieved 16 September 2026.
  4. 1 2 3 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. 1 2 3 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. 1 2 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.
  7. 1 2 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.
  8. ↑ Seligman, Courtney. "New General Catalogue Objects: NGC 4698". Celestial Atlas. Retrieved 16 September 2026.
  9. ↑ Buta, Ronald J.; et al. (2007), Atlas of Galaxies, Cambridge University Press, pp. 13–17, ISBN 978-0521820486.
  10. ↑ 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.
  11. ↑ 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.