NGC 6503

NGC 6503
HST image of NGC 6503's spiral arms[1]
Observation data (J2000 epoch)
ConstellationDraco
Right ascension17h 49m 26.4207s[2]
Declination+70° 08′ 39.587″[2]
Redshift0.000143[3]
Heliocentric radial velocity28[4] km/s
Distance20.9 ± 2.2 Mly (6.40 ± 0.66 Mpc)[4]
Apparent magnitude (V)10.2[5]
Characteristics
TypeSAB:(s)bc[6]
Apparent size (V)7.1′ × 2.4′[7]
Other designations
IRAS 17499+7009, 2MASX J17492651+7008396, UGC 11012, LEDA 60921, MCG +12-17-009[3]

NGC 6503 is a field[8] dwarf spiral galaxy [dubious – discuss] in the northern constellation of Draco. It was discovered by German astronomer Arthur von Auwers on July 22, 1854.[5] The galaxy has an angular size of 7.1′ × 2.4′[7] and an apparent visual magnitude of 10.2.[5] It is located at a distance of approximately 20.9 million light-years (6.40 Mpc) from the Milky Way galaxy.[4] NGC 6503 may form the remote tip of a long chain of galaxies that extends out into the local void, forming a galaxy filament spanning 26 million light-years (8 Mpc).[9]

The galactic plane of this galaxy is inclined at an angle of 78°±3° to the plane of the sky,[4] with the major axis of its oval profile being aligned along a position angle of 121°.[10] The morphological classification of NGC 6502 is SAB:(s)bc. This indicates a barred spiral galaxy (SAB:) with no inner ring structure (s) and moderately wound spiral arms (bc). However, the ':' notation indicates some uncertainty about the classification. Older works gave it a class of SA(s)bc; i.e. no bar.[6]

A possible bar system has been reported via infrared observations, being viewed end-on from the perspective of the Earth.[11][12] Ultraviolet observations show a young, inner star forming ring encircling the bar.[12] The ring has a radius between 1 and 2.5 kpc from the core.[13] There is a disk of neutral hydrogen that is larger in extent than the optical disk of the galaxy. This extra-planar gas is mostly the result of star formation activity, rather than cold gas that is being accreted.[14] There is evidence for a LINER-type or Seyfert 2 nucleus.[12]

NGC 6503 has one known satellite galaxy,[15] known as KK 242. With a stellar mass of about 3 million solar masses, KK 242 is on the border between a dwarf irregular galaxy (dIrr) and a dwarf spheroidal galaxy (dSph).[16]

References

  1. ^ "NGC 6503". space telescope.org. NASA/ESA. Retrieved 11 June 2015.
  2. ^ 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.
  3. ^ a b "NGC 6503". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2010-11-29.
  4. ^ a b c d Kourkchi, Ehsan; et al. (October 23, 2020). "Cosmicflows-4: The Catalog of ∼10,000 Tully–Fisher Distances". The Astrophysical Journal. 902 (2): 145. arXiv:2009.00733. Bibcode:2020ApJ...902..145K. doi:10.3847/1538-4357/abb66b. ISSN 1538-4357.
  5. ^ a b c O'Meara, Stephen James (2007). Hidden Treasures. Cambridge University Press. p. 423. ISBN 978-1-139-46373-7.
  6. ^ a b Buta, Ronald J.; et al. (2015). "A Classical Morphological Analysis of Galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S4G)". The Astrophysical Journal Supplement Series. 217 (2): 32. arXiv:1501.00454. Bibcode:2015ApJS..217...32B. doi:10.1088/0067-0049/217/2/32. S2CID 119202943.
  7. ^ a b Blanc, Guillermo A.; et al. (2013). "The Virus-P Exploration of Nearby Galaxies (Venga): Survey Design, Data Processing, and Spectral Analysis Methods". The Astronomical Journal. 145 (5): 138. arXiv:1303.1552. Bibcode:2013AJ....145..138B. doi:10.1088/0004-6256/145/5/138. S2CID 119109864.
  8. ^ Materne, J. (April 1979). "The structure of nearby groups of galaxies - Quantitative membership probabilities". Astronomy and Astrophysics. 74 (2): 235–243. Bibcode:1979A&A....74..235M.
  9. ^ Karachentseva, Valentina E.; et al. (October 2023). "The M 101 galaxy group as a node in a nearby cosmic filament". Astronomy & Astrophysics. 678. id. A16. arXiv:2308.01897. Bibcode:2023A&A...678A..16K. doi:10.1051/0004-6361/202347085.
  10. ^ Bottema, Roelof; Gerritsen, Jeroen P. E. (October 1997). "An investigation of the structure and kinematics of the spiral galaxy NGC 6503". Monthly Notices of the Royal Astronomical Society. 290 (4): 585–597. arXiv:astro-ph/9704190. doi:10.1093/mnras/290.4.585.
  11. ^ Kuzio de Naray, Rachel; et al. (December 2012). "Searching for non-axisymmetries in NGC 6503: a weak end-on bar". Monthly Notices of the Royal Astronomical Society. 427 (3): 2523–2536. arXiv:1209.4653. Bibcode:2012MNRAS.427.2523K. doi:10.1111/j.1365-2966.2012.22126.x.
  12. ^ a b c Freeland, E.; Chomiuk, L.; Keenan, R.; Nelson, T. (March 2010). "Evidence for a Strong End-On Bar in the Ringed σ-Drop Galaxy NGC 6503". The Astronomical Journal. 139 (3): 865–870. arXiv:0912.0247. Bibcode:2010AJ....139..865F. doi:10.1088/0004-6256/139/3/865.
  13. ^ Gouliermis, Dimitrios A.; et al. (October 2015). "Hierarchical star formation across the ring galaxy NGC 6503". Monthly Notices of the Royal Astronomical Society. 452 (4): 3508–3528. arXiv:1506.03928. Bibcode:2015MNRAS.452.3508G. doi:10.1093/mnras/stv1325.
  14. ^ Greisen, Eric W.; et al. (June 2009). "Aperture Synthesis Observations of the Nearby Spiral NGC 6503: Modeling the Thin and Thick H I Disks". The Astronomical Journal. 137 (6): 4718–4733. arXiv:0902.0989. Bibcode:2009AJ....137.4718G. doi:10.1088/0004-6256/137/6/4718.
  15. ^ Koda, Jin; et al. (April 2015). "Discovery of New Dwarf Galaxy Near the Isolated Spiral Galaxy NGC 6503". The Astrophysical Journal Letters. 802 (2). id. L24. arXiv:1504.00674. Bibcode:2015ApJ...802L..24K. doi:10.1088/2041-8205/802/2/L24.
  16. ^ Karachentsev, Igor D.; et al. (2022). "KK 242, A Faint Companion to the Isolated SCD Galaxy NGC 6503". The Astronomical Journal. 163 (2): 51. arXiv:2111.14691. Bibcode:2022AJ....163...51K. doi:10.3847/1538-3881/ac3cbe. S2CID 244714422.

Further reading

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