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

We study the orbital evolution and gravitational wave (GW) emission ofsupermassive black hole (SMBH) binaries formed in gas-free mergers of massiveearly-type galaxies using the hybrid tree-regularized N-body code KETJU. Theevolution of the SMBHs and the surrounding galaxies is followedself-consistently from the large-scale merger down to the final few orbitsbefore the black holes coalesce. Post-Newtonian corrections are included up toPN3.5-level for the binary dynamics, and the GW calculations include thecorresponding corrections up to PN1.0-level. We analyze the significance of thestellar environment on the evolution of the binary and the emitted GW signalduring the final GW emission dominated phase of the binary hardening andinspiral. Our simulations are compared to semi-analytic models that have oftenbeen used for making predictions for the stochastic GW background emitted bySMBHs. We find that the commonly used semi-analytic parameter values producelarge differences in merger timescales and eccentricity evolution, but resultin only $\sim 10\%$ differences in the GW spectrum emitted by a single binaryat frequencies $f\gtrsim 10^{-1} \, \rm yr^{-1}$, which are accessible bycurrent pulsar timing arrays. These differences are in part caused by thestrong effects of the SMBH binaries on the surrounding stellar population,which are not included in the semi-analytic models.

Gravitational Waves from the Inspiral of Supermassive Black Holes in Galactic-scale Simulations