UGC 12591 is the third most massive known spiral galaxy, after ISOHDFS 27 and J2345-0449.[citation needed] It is located about 400 million light-years away from the Earth in the constellation Pegasus. In addition, it is the spiral galaxy with the highest known rotational speed[2] of about 500 km/s, almost twice that of our galaxy, the Milky Way. The high rotational speed means the galaxy must be very massive at the center; the galaxy has a mass estimated at 4 times that of the Milky Way,[3] making it the third of the most massive spiral galaxies known to date.
| UGC 12591 | |
|---|---|
 UGC 12591, taken by the Hubble Space Telescope | |
| Observation data (J2000 epoch) | |
| Constellation | Pegasus |
| Right ascension | 23h 25m 21.7s[1] |
| Declination | 28° 29′ 43″[1] |
| Redshift | 0.023179[1] |
| Heliocentric radial velocity | 6949 ± 10[1] |
| Distance | 394.26 ± 133.84 Mly (120.880 ± 41.036 Mpc)[1] |
| Apparent magnitude (B) | 13.90[1] |
| Characteristics | |
| Type | S0/a[1] |
| Mass | 1.9×1012[2] M☉ |
| Apparent size (V) | 1.7′ × 0.7′[1] |
| Other designations | |
| MCG +05-55-015, PGC 71392 | |
UGC 12591 is relatively isolated; the nearest galaxy to it is 3.55 million light-years (1.09 Mpc) away. However, its morphology suggests a merger or accretion event in its past: it is somewhat lenticular-like, with a central bulge and dust lanes reminiscent of the Sombrero Galaxy.[4]
References edit
- ^ a b c d e f g h "NED results for object UGC 12591". National Aeronautics and Space Administration / Infrared Processing and Analysis Center. Retrieved 16 April 2017.
- ^ a b Giovanelli, R.; Haynes, M. P.; Rubin, V. C.; Ford, W. K. Jr. (1 February 1986). "UGC 12591 - The most rapidly rotating disk galaxy". The Astrophysical Journal Letters. 301: L7–L11. Bibcode:1986ApJ...301L...7G. doi:10.1086/184613. ISSN 0004-637X.
- ^ "A remarkable galactic hybrid". ESA/Hubble. Retrieved 16 April 2017.
- ^ Ray, Shankar; Bagchi, Joydeep; Dhiwar, Suraj; Pandge, M. B.; Mirakhor, Mohammad; Walker, Stephen A.; Mukherjee, Dipanjan (2022). "Hubble Space Telescope Captures UGC 12591: Bulge/Disc properties, star formation and 'missing baryons' census in a very massive and fast-spinning hybrid galaxy". Monthly Notices of the Royal Astronomical Society. 517 (1): 99–117. arXiv:2203.02885. Bibcode:2022MNRAS.517...99R. doi:10.1093/mnras/stac2683.
External links edit
Media related to UGC 12591 at Wikimedia Commons
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