Messier 106

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Messier 106
Messier 106 visible and infrared composite.jpg
M 106 and its anomalous arms. Composite of IR (red), x-ray (blue), radio (purple) and visible light view (Image credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team))
Observation data (J2000 epoch)
Constellation Canes Venatici
Right ascension 12h 18m 57.5s[1]
Declination +47° 18′ 14″[1]
Redshift 448 ± 3 km/s[1]
Distance 23.7 ± 1.5 Mly (7 ± 0.5 Mpc)[2][3]
Type SAB(s)bc[1]
Size (ly) 135,000 ly (in diameter)[4]
Apparent dimensions (V) 18′.6 × 7′.2[1]
Apparent magnitude (V) 9.1[1]
Notable features Maser galaxy,[5] Seyfert II galaxy.[6]
Other designations
M 106, NGC 4258, UGC 7353, PGC 39600.[1][7]
See also: Galaxy, List of galaxies
Messier 106 (left) with possible companion galaxy NGC 4217 (lower right)

Messier 106 (also known as NGC 4258) is a spiral galaxy in the constellation Canes Venatici. It was discovered by Pierre Méchain in 1781. M106 is at a distance of about 22 to 25 million light-years away from Earth. It is also a Seyfert II galaxy. Due to x-rays and unusual emission lines detected, it is suspected that part of the galaxy is falling into a supermassive black hole in the center.[8] NGC 4217 is a possible companion galaxy of Messier 106.[7]


M106 has a water vapor megamaser (the equivalent of a laser operating in microwave instead of visible light and on a galactic scale) that is seen by the 22-GHz line of ortho-H2O that evidences dense and warm molecular gas. These water vapors give M106 its characteristic purple color.[9] Water masers are useful to observe nuclear accretion disks in active galaxies. The water masers in M106 enabled the first case of a direct measurement of the distance to a galaxy and thereby providing an independent anchor for the cosmic distance ladder.[10][11] M 106 has a slightly warped, thin, almost edge-on Keplerian disc which is on a subparsec scale. It surrounds a central area with mass 4 × 107M.[12]

It is one of the largest and brightest nearby galaxies, similar in size and luminosity to the Andromeda Galaxy.[13]

See also[edit]


  1. ^ a b c d e f g "NASA/IPAC Extragalactic Database". Results for Messier 106. Retrieved 2006-12-07. 
  2. ^ Tonry, J. L. et al. (2001). "The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances". Astrophysical Journal 546 (2): 681–693. arXiv:astro-ph/0011223. Bibcode:2001ApJ...546..681T. doi:10.1086/318301. 
  3. ^ Macri, L. M. et al. (2006). "A New Cepheid Distance to the Maser-Host Galaxy NGC 4258 and Its Implications for the Hubble Constant". Astrophysical Journal 652 (2): 1133–1149. arXiv:astro-ph/0608211. Bibcode:2006ApJ...652.1133M. doi:10.1086/508530. 
  4. ^ freestarcharts
  5. ^ Bonanos, Alceste Z. (2006). "Eclipsing Binaries: Tools for Calibrating the Extragalactic Distance Scale". Proceedings of the International Astronomical Union 2 (S240). arXiv:astro-ph/0610923. Bibcode:2007IAUS..240...79B. doi:10.1017/S1743921307003845. 
  6. ^ Humphreys, E. M. L. et al. (2004). "Improved Maser Distance to NGC 4258". Bulletin of the American Astronomical Society 36: 1468. Bibcode:2004AAS...205.7301H. 
  7. ^ a b "SIMBAD Astronomical Object Database". Results for Messier 106. Retrieved 2006-12-07. 
  8. ^ "A spiral galaxy with a strange core". Astronomy Picture of the Day. 
  9. ^ Color analysis of M106:
  10. ^ JR Herrnstein et al. (1999). "A geometric distance to the galaxy NGC 4258 from orbital motions in a nuclear gas disk". Nature 400: 539–541. arXiv:astro-ph/9907013. Bibcode:1999Natur.400..539H. doi:10.1038/22972. 
  11. ^ Richard de Grijs (2011). An Introduction to Distance Measurement in Astronomy. Chichester: John Wiley & Sons. p. 109. ISBN 978-0-470-51180-0. 
  12. ^ Henkel, C. et al. (2005). "New H2O masers in Seyfert and FIR bright galaxies". Astronomy and Astrophysics 436 (1): 75–90. arXiv:astro-ph/0503070. Bibcode:2005A&A...436...75H. doi:10.1051/0004-6361:20042175. 
  13. ^ Karachentsev, Igor D.; Karachentseva, Valentina E.; Huchtmeier, Walter K.; Makarov, Dmitry I. (2003). "A Catalog of Neighboring Galaxies". The Astronomical Journal 127 (4): 2031–2068. Bibcode:2004AJ....127.2031K. doi:10.1086/382905. 

External links[edit]

Coordinates: Sky map 12h 18m 57.5s, +47° 18′ 14″