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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Understanding how supermassive black holes (SMBHs) pair and merge helps toinform predictions of off-center, dual, and binary AGN, and provides keyinsights into how SMBHs grow and co-evolve with their galaxy hosts. As theloudest known gravitational wave source, binary SMBH mergers also holdcenterstage for the Laser Interferometer Space Antenna (LISA), a joint ESA/NASAgravitational wave observatory set to launch in 2034. Here, we continue ourwork to characterize SMBH binary formation and evolution through increasinglymore realistic high resolution direct $N$-body simulations, focusing on theeffect of SMBH mass ratio, orientation, and eccentricity within a rotating andflattened stellar host. During the dynamical friction phase, we found aprolonged orbital decay for retrograde SMBHs and swift pairing timescales forprograde SMBHs compared to their counterparts in non-rotating models, an effectthat becomes more pronounced for smaller mass ratios $M_{\rm sec}/M_{\rm prim}= q$. During this pairing phase, the eccentricity dramatically increases forretrograde configurations, but as the binary forms, the orbital plane flips sothat it is almost perfectly prograde, which stifles the rapid eccentricitygrowth. In prograde configurations, SMBH binaries form and remain atcomparatively low eccentricities. As in our prior work, we note that the centerof mass of a prograde SMBH binary itself settles into an orbit about the centerof the galaxy. Since even the initially retrograde binaries flip their orbitalplane, we expect few binaries in rotating systems to reside at rest in thedynamic center of the host galaxy, though this effect is smaller as $q$decreases.

Inward Bound: The incredible journey of massive black holes as they pair and merge; I. The effect of mass ratio in flattened rotating galactic nuclei