English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Our Galaxy and the nearby Andromeda galaxy (M31) are the most massive membersof the Local Group, and they seem to be a bound pair, despite the uncertaintieson the relative motion of the two galaxies. A number of studies have shown thatthe two galaxies will likely undergo a close approach in the next 4$-$5 Gyr. Weused direct $N$-body simulations to model this interaction to shed light on thefuture of the Milky Way - Andromeda system and for the first time explore thefate of the two supermassive black holes (SMBHs) that are located at theircenters. We investigated how the uncertainties on the relative motion of thetwo galaxies, linked with the initial velocities and the density of the diffuseenvironment in which they move, affect the estimate of the time they need tomerge and form ``Milkomeda''. After the galaxy merger, we follow the evolutionof their two SMBHs up to their close pairing and fusion. Upon the fiducial setof parameters, we find that Milky Way and Andromeda will have their closestapproach in the next 4.3 Gyr and merge over a span of 10 Gyr. Although the timeof the first encounter is consistent with other predictions, we find that themerger occurs later than previously estimated. We also show that the two SMBHswill spiral in the inner region of Milkomeda and coalesce in less than 16.6 Myrafter the merger of the two galaxies. Finally, we evaluate thegravitational-wave emission caused by the inspiral of the SMBHs, and we discussthe detectability of similar SMBH mergers in the nearby Universe ($z\leq 2$)through next-generation gravitational-wave detectors.

Future merger of the Milky Way with the Andromeda galaxy and the fate of their supermassive black holes