NGC 4424

NGC 4424
NGC 4424 imaged by the Vera C. Rubin Observatory
Observation data (J2000 epoch)
ConstellationVirgo
Right ascension12h 27m 11.575s
Declination+09° 25′ 14.32″
Redshift0.00146
Heliocentric radial velocity442
Distance13.5 Mly (4.1 Mpc)
Group or clusterVirgo Cluster
Characteristics
TypeSB(s)a peculiar
Mass3.8+2.3
−1.4×108 M☉
Other designations
IRAS 12246+0941, 2MASX J12271158+0925138, UGC 7561, MCG +02-32-058, PGC 40809

NGC 4424 is a spiral galaxy located in the equatorial constellation of Virgo. It was discovered February 27, 1865 by German astronomer Heinrich Louis d'Arrest. This galaxy is located at a distance of 13.5 million light years and is receding with a heliocentric radial velocity of 442 km/s. It has a morphological class of SB(s)a, which normally indicates a spiral galaxy with a barred structure (SB), no inner ring feature (s), and tightly-wound spiral arms (a). The galactic plane is inclined at an angle of 62° to the line of sight from the Earth. It is a likely member of the Virgo Cluster of galaxies.

NGC 4424 imaged by the Hubble Space Telescope; the smaller galaxy IC 3366 is below center

The galaxy NGC 4424 has a peculiar morphology with shells that give the appearance of a galaxy merger within the last half billion years. It has a long tail of hydrogen stretching 110 kpc to the south that is likely due to stripping from ram pressure. Because of the lack of gas, star formation has completely ceased in the outer parts of the galaxy, while there is still a mild amount occurring in the inner region. NGC 4424 will most likely end up as a lenticular galaxy by three billion years from now.

There is no indication of an active, compact source of X-ray emission at the very center of NGC 4424, but there is an ionized tail stretching ~10 kpc from the core. Based on its stellar mass and velocity dispersion, the galaxy's center is predicted to host an intermediate-mass black hole (IMBH) of approximately (0.8±0.2)×105 M☉. Hubble images show a red, tidally stretched star cluster—named "Nikhuli"—located at a projected distance of about 5″ (~400 pc) from the nucleus. Nikhuli has a stellar mass of (3.44±0.93)×106 M☉ and is elongated toward the galaxy's center, suggesting it may be the captured nuclear star cluster of a stripped galaxy undergoing tidal shredding during a minor merger. Coincident with Nikhuli is an X-ray point source, NGC 4424 X-3, which exhibits a luminosity of L0.5–8 keV ≈ 6×1038 erg s−1 and is interpreted as an active massive black hole (with an estimated mass of ∼0.7×105 M☉). This cluster is expected to sink to the center of NGC 4424 due to dynamical friction on a timescale of roughly 100 to 220 million years, potentially seeding the bulgeless host with its central black hole. The discovery of Nikhuli and its potential role in black hole seeding attracted widespread coverage in popular science and mainstream media.

Supernovae

Two supernovae have been observed in NGC 4424:

References

  1. 1 2 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. 1 2 3 4 Chakradhari, N. K.; et al. (August 2019). "Optical and UV studies of type Ia supernovae SN 2009ig and SN 2012cg". Monthly Notices of the Royal Astronomical Society. 487 (2): 1886–1904. Bibcode:2019MNRAS.487.1886C. doi:10.1093/mnras/stz1358.
  3. 1 2 Tully, R. Brent (May 2015). "Galaxy Groups: A 2MASS Catalog". The Astronomical Journal. 149 (5): 14. arXiv:1503.03134. Bibcode:2015AJ....149..171T. doi:10.1088/0004-6256/149/5/171. S2CID 119285986. 171.
  4. 1 2 3 Lianou, S.; et al. (November 2019). "Dust properties and star formation of approximately a thousand local galaxies". Astronomy & Astrophysics. 631: 19. arXiv:1906.02712. Bibcode:2019A&A...631A..38L. doi:10.1051/0004-6361/201834553. S2CID 174801441. A38.
  5. 1 2 3 4 Boselli, A.; et al. (December 2018). "A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE). IV. A tail of ionised gas in the merger remnant NGC4424". Astronomy & Astrophysics. 620: 16. arXiv:1810.09234. Bibcode:2018A&A...620A.164B. doi:10.1051/0004-6361/201833914. S2CID 229156290. A164.
  6. ↑ "HyperLeda -object description". leda.univ-lyon1.fr. Retrieved 27 March 2017.
  7. ↑ "NGC 4424". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 27 March 2017.
  8. ↑ Anderson, Natali (Mar 27, 2017). "Hubble Observes Barred Spiral Galaxy NGC 4424". Science News. Retrieved 2021-12-25.
  9. 1 2 3 4 Graham, Alister W.; et al. (December 2021). "Potential Black Hole Seeding of the Spiral Galaxy NGC 4424 via an Infalling Star Cluster". The Astrophysical Journal. 923 (2): 14. arXiv:2112.05318. Bibcode:2021ApJ...923..146G. doi:10.3847/1538-4357/ac235b. S2CID 245117870. 146.
  10. ↑ "NASA Telescopes Capture Stellar Delivery Service for Black Hole". NASA. August 18, 2022. Retrieved June 2, 2026.
  11. ↑ "NGC 4424: NASA Telescopes Capture Stellar Delivery Service for Black Hole". Chandra X-ray Observatory. Harvard-Smithsonian Center for Astrophysics. August 18, 2022. Retrieved June 2, 2026.
  12. ↑ Lea, Robert (August 22, 2022). "Galaxy's violent destruction acted as 'black hole delivery service'". Space.com. Retrieved June 2, 2026.
  13. ↑ Plait, Phil (August 2022). "Black hole delivery pipeline may feed a nearby galaxy". Syfy Wire (Bad Astronomy). Retrieved June 2, 2026.
  14. ↑ Rayne, Elizabeth (January 2022). "How two galaxies got the gift of a black hole". Syfy Wire. Retrieved June 2, 2026.
  15. ↑ Wolf, M. (1925). "Variabilis (? Nova) 94.1925 Virginis". Astronomische Nachrichten. 226 (5): 75. Bibcode:1925AN....226...75W. doi:10.1002/asna.19252260504.
  16. ↑ "SN 1895A". Transient Name Server. IAU. Retrieved 3 June 2025.
  17. ↑ Kandrashoff, M.; et al. (May 2012). Green, D. W. E. (ed.). "Supernova 2012cg in NGC 4424 = Psn J12271283+0925132". Central Bureau Electronic Telegrams (3111): 1. Bibcode:2012CBET.3111....1K.
  18. ↑ "SN 2012cg". Transient Name Server. IAU. Retrieved 3 June 2025.
  19. ↑ Munari, U.; et al. (April 2013). "BVRI lightcurves of supernovae SN 2011fe in M101, SN 2012aw in M95, and SN 2012cg in NGC 4424". New Astronomy. 20: 30–37. arXiv:1209.4692. Bibcode:2013NewA...20...30M. doi:10.1016/j.newast.2012.09.003. S2CID 53975401.
  20. ↑ Bishop, David. "Bright Supernovae - 2012". Rochester Astronomy. Retrieved 8 December 2024.
  21. 1 2 Shappee, B. J.; et al. (March 2018). "Strong Evidence against a Non-degenerate Companion in SN 2012cg". The Astrophysical Journal. 855 (1): 10. arXiv:1610.07601. Bibcode:2018ApJ...855....6S. doi:10.3847/1538-4357/aaa1e9. S2CID 73720425. 6.