NGC 5170 is a large, nearby,[6] edge-on spiral galaxy in the equatorial constellation of Virgo. It was discovered on February 7, 1785 by William Herschel. This galaxy is located at a distance of 83.5 million light years and is receding at a heliocentric radial velocity of 1,502 km/s.[3] It is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster.[7]

NGC 5170
NGC 5170 imaged by the Hubble Space Telescope
Observation data (J2000 epoch)
ConstellationVirgo
Right ascension13h 29m 48.769s[1]
Declination−17° 57′ 59.39″[1]
Redshift0.005006[2]
Heliocentric radial velocity1,502 km/s[3]
Galactocentric velocity1,386 km/s[3]
Distance83.5 Mly (25.59 Mpc)[3]
Apparent magnitude (V)12.4[2]
Apparent magnitude (B)12.07[3]
Absolute magnitude (V)−21.6[4]
Characteristics
TypeSA(s)c: sp[2]
Apparent size (V)9′.9 × 1′.2[2]
Other designations
IRAS 13271-1742, NGC 5170, LEDA 47394, MCG -03-34-084, PGC 47394[3][5]

The inclination of the galactic plane of NGC 5170 is tilted at an angle of ~86° to the line of sight from the Earth, which means the disk is significantly obscured. It is estimated to have a morphological class of type Sb to Sc, meaning the spiral arms are moderate to loosely wound. The bulge-to-disk ratio of 0.5 is more consistent with an Sb galaxy.[4] It has an estimated star formation rate of 1.37±0.23 M·yr−1, which is more than double the rate in the Milky Way.[4]

The galactic latitude of this star is 43°, making the field relatively free of stars in the Milky Way. Combined with the proximity and edge-on view of NGC 5170, this makes galaxy useful for studies of its globular cluster population. It is estimated to have a total of 600±100 globulars, which is much higher than for the Milky Way. A candidate ultra-compact dwarf galaxy has been identified that is associated with NGC 5170.[4]

Numerical modeling of this galaxy indicates it has a massive dark halo with a thin, low surface brightness disk.[6] The halo mass of NGC 5170 is 3.4×1012 M.[4] Examination of the galaxy with the Chandra X-ray Observatory showed there is no diffuse X-ray emission from hot gas in the extended galactic halo.[8]

References

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  1. ^ a b 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. ^ a b c d "NASA/IPAC Extragalactic Database". Results for NGC 5170. Retrieved 2007-04-03.
  3. ^ a b c d e f Tully, R. Brent; et al. (2016). "Cosmicflows-3". The Astronomical Journal. 152 (2): 21. arXiv:1605.01765. Bibcode:2016AJ....152...50T. doi:10.3847/0004-6256/152/2/50. S2CID 250737862. 50.
  4. ^ a b c d e Forbes, Duncan A.; et al. (March 2010). "A blue tilt in the globular cluster system of the Milky Way-like galaxy NGC 5170". Monthly Notices of the Royal Astronomical Society. 403 (1): 429–438. arXiv:0911.4743. Bibcode:2010MNRAS.403..429F. doi:10.1111/j.1365-2966.2009.16130.x. S2CID 59570601.
  5. ^ "NGC 5170". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-12-26.
  6. ^ a b Khoperskov, A.; et al. (July 2010). "Numerical modelling of the vertical structure and dark halo parameters in disc galaxies". Astronomische Nachrichten. 331 (7): 731. arXiv:1007.4693. Bibcode:2010AN....331..731K. doi:10.1002/asna.200911402. S2CID 55488734.
  7. ^ "The Virgo III Groups". Atlas of the Universe. Retrieved 2010-11-27.
  8. ^ Pedersen, Kristian; et al. (May 2006). "Discovery of a very extended X-ray halo around a quiescent spiral galaxy The "missing link" of galaxy formation". New Astronomy. 11 (7): 465–470. arXiv:astro-ph/0511682. Bibcode:2006NewA...11..465P. doi:10.1016/j.newast.2005.11.004. S2CID 53473787.
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