A disc galaxy (or disk galaxy) is a galaxy characterized by a galactic disc. This is a flattened circular volume of stars that are mainly orbiting the galactic core in the same plane,[1] although not always in the same direction.[2][3] These galaxies may or may not include a central non-disc-like region (a galactic bulge).[4] They will typically have an orbiting mass of gas and dust in the same plane as the stars. (A lenticular galaxy may be former spiral galaxy from which much of the gas and dust has been stripped.[5]) Interactions with other nearby galaxies can perturb and stretch the galactic disk, sometimes completely disrupting the disk.[6]
Disc galaxy types include:
- Spiral galaxies:
- Unbarred spiral galaxies: (types S, SA)
- Barred spiral galaxies: (type SB)
- Intermediate spiral galaxies: (type SAB)
- Lenticular galaxies: (types E8, S0, SA0, SB0, SAB0)
Galaxies that are not disc types include:
- Elliptical galaxies: (type dE)
- Irregular galaxies: (type dI)
See also
References
- ^ “Disk Galaxies | COSMOS”. astronomy.swin.edu.au.
- ^ Kuijken, Konrad (September 1993). “Counter-Rotating Populations in a Disk Galaxy”. Publications of the Astronomical Society of the Pacific. 105: 1016. Bibcode:1993PASP..105.1016K. doi:10.1086/133275.
- ^ Rubino, M.; et al. (October 2021). “Detectability of large-scale counter-rotating stellar disks in galaxies with integral-field spectroscopy”. Astronomy & Astrophysics. 654. id. A30. arXiv:2107.02226. Bibcode:2021A&A…654A..30R. doi:10.1051/0004-6361/202140702.
- ^ “The Galactic Bulge”. burro.case.edu.
- ^ van den Bergh, Sidney (September 2009). “Lenticular Galaxies and their Environments”. The Astrophysical Journal. 702 (2): 1502–1506. arXiv:0907.3715. Bibcode:2009ApJ…702.1502V. doi:10.1088/0004-637X/702/2/1502.
- ^ Moore, Ben; et al. (April 1999). “On the survival and destruction of spiral galaxies in clusters”. Monthly Notices of the Royal Astronomical Society. 304 (3): 465–474. arXiv:astro-ph/9811127. Bibcode:1999MNRAS.304..465M. doi:10.1046/j.1365-8711.1999.02345.x.
