Prolate rotator galaxy
{{short description|Class of galaxy that is cigar shaped and rotates around its long axis}}
{{Redirect|Spindle Galaxy|the galaxy commonly referred to as the "Spindle Galaxy"|NGC 3115}}
A prolate rotator galaxy, or spindle galaxy, is an unusual class of galaxy that is cigar-shaped and rotates around its long axis.{{cite web |url=http://www.mpia.de/news/science/2017-11-prolate-galaxies |title=Astronomers discover unusual spindle-like galaxies |publisher=Max Planck Institute for Astronomy |first=Markus |last=Pössel |date=12 October 2017 |access-date=9 January 2018}} A prolate rotator galaxy is an elliptical galaxy in prolate rotation,{{cite news |url=https://www.newsweek.com/spindle-galaxies-rare-discovered-astronomers-684224 |title=Eight Weird, Spindle-Like Galaxies Discovered by Astronomers |work=Newsweek |first=Hannah |last=Osborne |date=13 October 2017 |access-date=9 January 2018}} meaning they possess a significant amount of rotation around their major axis. To create a prolate rotator galaxy, two large spiral galaxies must collide at right angles.{{cite journal |title=CALIFA reveals prolate rotation in massive early-type galaxies: A polar galaxy merger origin? |journal=Astronomy & Astrophysics |first1=A. |last1=Tsatsi |first2=M. |last2=Lyubenova |first3=G. |last3=van de Ven |first4=J. |last4=Chang |first5=J. A. L. |last5=Aguerri |first6=J. |last6=Falcón-Barroso |first7=A. V. |last7=Macciò |display-authors=1 |volume=606 |at=A62 |date=October 2017 |arxiv=1707.05130 |doi=10.1051/0004-6361/201630218 |bibcode=2017A&A...606A..62T|s2cid=54571420 }} One forms the central bar, the other the disk. The bar then dominates the system.
{{As of|2017}}, 20 such galaxies were known. Their existence is also predicted by large-scale cosmological simulations. {{cite journal |title=Galaxies with Prolate Rotation in Illustris |journal=The Astrophysical Journal |first1=Ivana |last1=Ebrová |first2=Ewa L. |last2=Łokas |name-list-style=amp |volume=850 |issue=2 |at=144 |date=December 2017 |arxiv=1708.03311 |doi=10.3847/1538-4357/aa96ff |bibcode=2017ApJ...850..144E|s2cid=96422162 |doi-access=free }}