Template:Short description Template:Use dmy dates Template:Infobox Galaxy Messier 106 (also known as NGC 4258) is an intermediate 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. M106 contains an active nucleus classified as a Type 2 Seyfert, and the presence of a central supermassive black hole has been demonstrated from radio-wavelength observations of the rotation of a disk of molecular gas orbiting within the inner light-year around the black hole.<ref name="miyoshi1995">Template:Cite journal</ref> NGC 4217 is a possible companion galaxy of Messier 106.<ref name="SIMBAD"/> Besides the two visible arms, it has two "anomalous arms" detectable using an X-ray telescope.
CharacteristicsEdit
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. Water masers are useful for observing 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, thereby providing an independent anchor for the cosmic distance ladder.<ref>Template:Cite journal</ref><ref>Template:Cite book</ref> M106 has a slightly warped, thin, almost edge-on Keplerian disc which is on a subparsec scale. It surrounds a central area with mass Template:Val.<ref name="Henkeletal2005"/>
It is one of the largest and brightest nearby galaxies, similar in size and luminosity to the Andromeda Galaxy.<ref name="Karachentsev2004">Template:Cite journal</ref> The supermassive black hole at the core has a mass of Template:Val.<ref name=Graham2008>Template:Cite journal</ref>
M106 has also played an important role in calibrating the cosmic distance ladder. Before, Cepheid variables from other galaxies could not be used to measure distances since they cover ranges of metallicities different from the Milky Way's. M106 contains Cepheid variables similar to both the metallicities of the Milky Way and other galaxies' Cepheids. By measuring the distance of the Cepheids with metallicities similar to our galaxy, astronomers are able to recalibrate the other Cepheids with different metallicities, a key fundamental step in improving quantification of distances to other galaxies in the universe.<ref name="Macrietal2006" />
SupernovaeEdit
Two supernovae have been observed in M106:
- SN 1981K (type II, mag. 17) was reported by E. Hummel and verified by Paul Wild by examining archival photos dated 3 November 1981.<ref>Template:Cite journal</ref><ref>{{#invoke:citation/CS1|citation
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- SN 2014bc (type II, mag. 14.8) was discovered by the PS1 Science Consortium 3Pi survey on 19 May 2014.<ref>Template:Cite journal</ref><ref>{{#invoke:citation/CS1|citation
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See alsoEdit
ReferencesEdit
External linksEdit
- StarDate: M106 Fact Sheet
- Spiral Galaxy M106 at SEDS Messier pagesTemplate:WikiSky
- NGC 4258: Mysterious Arms Revealed
- Spiral Galaxy Messier 106 (NGC 4258) at the astro-photography site of Takayuki Yoshida
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- Messier 106 at Constellation Guide
Template:Sky Template:Portal bar Template:Catalogs Template:Messier objects Template:List of Seyfert galaxies Template:Ngc45Template:Stars of Canes Venatici