Andromeda Milky Way Collision
The collision of the Andromeda Galaxy with our Milky Way Galaxy is a predicted astronomical event . The merger of the two spiral galaxies is expected in a few billion years.
The Milky Way has an estimated 100 to 300 billion stars with a mass of around 1500 billion solar masses , while the Andromeda Galaxy has a mass of around 800 billion solar masses. The two galaxies are by far the heaviest of the Local Group .
The American astrophysicists Thomas J. Cox and Abraham Loeb call the fusion product of the two galaxies "Milkomeda". This name is made up of Andromeda and Milky Way ( English for Milky Way).
Research history
Observations and calculations revealed that both galaxies are moving towards each other at a speed of around 120 km / s. Whether and when this would lead to a collision, however, could not be answered exactly at first, as this also depends on the tangential speed of the Andromeda galaxy, i.e. the speed perpendicular to the line of sight. If this is significantly higher than the speed at which the two galaxies are moving towards each other ( radial speed ), both galaxies would simply pass each other without colliding. Calculations from 2001 showed a tangential speed of a maximum of 200 km / s, whereby a collision could not be confirmed, but also not excluded. Only later, in 2012, was it possible to use observations from the Hubble Space Telescope to calculate that the tangential speed is significantly less than 120 km / s, which is why a collision is now considered inevitable.
Due to the high complexity of the problem, it is very difficult to predict the exact course of the event. It is unlikely that individual stars will collide as the distances between them are very large. There are different estimates for the collision period.
According to NASA estimates, the event will begin in 3 to 4 billion years and take about 3 billion years for the fusion product to form. Computer simulations show that an elliptical or a polar ring galaxy would arise. The triangular galaxy could also merge with both galaxies when they move towards each other.
literature
- NASA's Hubble Shows Milky Way is Destined for Head-On Collision. NASA May 31, 2012, archived from the original on July 1, 2014 ; accessed on November 12, 2015 .
- John Dubinski: The Great Intergalactic Clash. Spektrum.de, accessed on November 7, 2015 .
- John Dubinski: The Great Milkyway Andromeda Collision. highpoint.edu, accessed November 7, 2015 .
- TJ Cox, Abraham Loeb : The collision between the Milky Way and Andromeda . In: Monthly Notices of the Royal Astronomical Society . tape 386 , no. 1 , May 2008, p. 461-474 , doi : 10.1111 / j.1365-2966.2008.13048.x .
Web links
- Explanation and course of a possible scenario
- dpa: Galaxy collision: The Milky Way is heating towards its end. In: zeit.de . June 1, 2012, accessed September 16, 2017 .
- Galaxy Collision: Crash with Andromeda Nebula will throw Earth away. In: Spiegel Online . May 15, 2007, accessed September 16, 2017 .
Individual evidence
- ↑ Researchers have recalculated the mass of the Milky Way - it changes the view of our galaxy
- ^ L. Watkins, R. van der Marel, S. Sohn, W. Evans: Evidence for an Intermediate-Mass Milky Way from Gaia DR2 Halo Globular Cluster Motions. In: The Astrophysical Journal. Volume 873, No. 2, March 2019; see. ESA article , accessed March 16, 2019.
- ↑ Prajwal R Kafle, Sanjib Sharma, F Geraint Lewis, Aaron SG Robotham, Simon P Driver; The need for speed: escape velocity and dynamical mass measurements of the Andromeda Galaxy , Monthly Notices of the Royal Astronomical Society, Volume 475, Issue 3, 11 April 2018, Pages 4043–4054, https://doi.org/10.1093/mnras / sty082
- ^ Ron Cowen: Andromeda on collision course with the Milky Way . In: Nature . doi : 10.1038 / nature.2012.10765 ( nature.com [accessed December 14, 2015]).
- ^ Z. Levay, R. van der Marel, T. Hallas, A. Mellinger: Illustration to the collision path , published by NASA