NGC 925

NGC 925 Amatha Galaxy is a barred spiral galaxy located about 30[4] million light-years away in the constellation Triangulum. The morphological classification of this galaxy is SB(s)d,[3] indicating that it has a bar structure and loosely wound spiral arms with no ring.[6] The spiral arm to the south is stronger than the northern arm, with the latter appearing flocculent and less coherent. The bar is offset from the center of the galaxy and is the site of star formation all along its length. Both of these morphological traits—a dominant spiral arm and the offset bar—are typically characteristics of a Magellanic spiral galaxy.[7] The galaxy is inclined at an angle of 55° to the line of sight along a position angle of 102°.[3]

NGC 925 Amatha Galaxy
NGC 925 Amatha Galaxy imaged with the 32 inch telescope at Mount Lemmon Observatory
Observation data (J2000 epoch)
ConstellationTriangulum
Right ascension02h 27m 16.913s[1]
Declination+33° 34′ 43.97″[1]
Redshift553 ± 3 km/s[2]
Helio radial velocity564[3] km/s
Distance30.3 ± 2.3 million light years (9.29 ± 0.69 Mpc)[4]
Group or clusterNGC 1023 Group[5]
Apparent magnitude (V)10.7[2]
Characteristics
TypeSB(s)d[3]
Apparent size (V)10′.5 × 5′.9[2]
Other designations
PGC 009332, UGC 01913[2]

The Amatha galaxy is a member of the NGC 1023 Group, a nearby, gravitationally-bound group of galaxies associated with NGC 1023.[5] However, the nearest member lies at least 650,000 ly (200,000 pc) distant from NGC 925. There is a 10 million solar mass (M☉) cloud of neutral hydrogen attached to NGC 925 by a streamer. It is uncertain whether this is a satellite dwarf galaxy, the remnant of a past tidal interaction, or a cloud of primordial gas.[8]

References
  1. Skrutskie, M. F.; et al. (February 2006), "The Two Micron All Sky Survey (2MASS)", The Astronomical Journal, 131 (2): 1163–1183, Bibcode:2006AJ....131.1163S, doi:10.1086/498708.
  2. "NASA/IPAC Extragalactic Database". Results for NGC 925. Retrieved 2008-12-28.
  3. Martin, Pierre; Roy, Jean-Rene (April 1994), "The influence of bars on the chemical composition of spiral galaxies", Astrophysical Journal, Part 1, 424 (2): 599–614, Bibcode:1994ApJ...424..599M, doi:10.1086/173917.
  4. Silbermann, N. A.; et al. (October 1996), "The Hubble Space Telescope Key Project on the Extragalactic Distance Scale. VI. The Cepheids in NGC 925", Astrophysical Journal, 470: 1, Bibcode:1996ApJ...470....1S, doi:10.1086/177845.
  5. Tully, R. B. (April 1980), "Nearby groups of galaxies. I - The NGC 1023 group", Astrophysical Journal, Part 1, 237: 390–403, Bibcode:1980ApJ...237..390T, doi:10.1086/157881.
  6. Buta, Ronald J.; et al. (2007), Atlas of Galaxies, Cambridge University Press, pp. 13–17, ISBN 978-0521820486.
  7. Pisano, D. J.; Wilcots, Eric M.; Elmegreen, Bruce G. (August 2000), "Structure and Star Formation in NGC 925", The Astronomical Journal, 120 (2): 763–776, arXiv:astro-ph/0004219, Bibcode:2000AJ....120..763P, doi:10.1086/301464, S2CID 119423281.
  8. Pisano, D. J.; et al. (June 2007), "An H I Survey of Six Local Group Analogs. I. Survey Description and the Search for High-Velocity Clouds", The Astrophysical Journal, 662 (2): 959–968, arXiv:astro-ph/0703279, Bibcode:2007ApJ...662..959P, doi:10.1086/517986, S2CID 15120531.
  • Media related to NGC 925 at Wikimedia Commons


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