Inference on inner galaxy structure via gravitational waves from supermassive binaries
| Title: | Inference on inner galaxy structure via gravitational waves from supermassive binaries |
|---|---|
| Authors: | Chen Y; Daniel M; D'Orazio DJ; Fan X; Mitridate A; Sagunski L; Xue X; Young O; Wright D; Witt CA; Wahl HM; Vigeland SJ; van Haasteren R; Vallisneri M; Unal C; Turner JE; Taylor SR; Taylor J; Swiggum JK; Susobhanan A; Stovall K; Stinebring DR; Stairs IH; Sosa Fiscella SV; Siwek MS; Simon J; Siemens X; Shapiro-Albert BJ; Schmitz K; Schmiedekamp C; Schmiedekamp A; Sardesai SC; Saffer A; Runnoe JC; Romano JD; Ray PS; Ransom SM; Radovan HA; Pol NS; Petrov P; Perera BBP; Pennucci TT; Olum KD; Ocker SK; Nice DJ; Ng C; Mingarelli CMF; Meyers PM; Meyers BW; McMann N; McLaughlin MA; McKee JW; McEwen A; Madison DR; Ma C-P; Lynch RS; Luo J; Lorimer DR; Liu T; Lewandowska N; Lazio TJW; Larsen B; Lamb WG; Lam MT; Laal N; Key JS; Kerr M; Kelley LZ; Kaplan DL; Jones ML; Johnson AD; Jennings RJ; Hazboun JS; Gultekin K; Good DC; Glaser J; Gersbach KA; Gentile PA; Garver-Daniels N; Gardiner EC; Freedman GE; Fonseca E; Fiore W; Ferrara EC; Dolch T; Dey L; Deng H; Demorest PB; DeCesar ME; Crowter K; Cromartie HT; Crawford F; Cornish NJ; Cordes JM; Cohen T; Chatterjee S; Charisi M; Casey-Clyde JA; Burnette R; Burke-Spolaor S; Brook PR; Brazier A; Blecha L; Becsy B; Baker PT; Baier JG; Arzoumanian Z; Archibald AM; Anumarlapudi A; Agazie G |
| Source: | Nature Astronomy, 2026 |
| Publisher Information: | Nature Research |
| Publication Year: | 2026 |
| Collection: | Newcastle University Library ePrints Service |
| Description: | © The Author(s), under exclusive licence to Springer Nature Limited 2026.The detection of a stochastic gravitational wave background by pulsar-timing arrays indicates the presence of a population of supermassive black hole binaries. Although the observed spectrum generally matches predictions for orbital evolution driven by gravitational-wave emission in circular orbits, there is a preference for a spectral turnover at the lowest observed frequencies, which may point to substantial hardening during a transition from early environmental influences to later stages dominated by emission. In the vicinity of these binaries, the ejection of stars or dark matter particles through gravitational three-body slingshots efficiently extracts orbital energy, leading to a low-frequency turnover in the spectrum. Here we model how the gravitational-wave spectrum depends on the initial inner galactic profile before scouring by binary ejections while accounting for a range of initial binary eccentricities. By analysing the NANOGrav 15-year data, we find that a parsec-scale galactic-centre density of around 106 M⊙ pc−3 is favoured across most of the parameter space, thus shedding light on the environmental effects that shape black hole evolution and the combined matter density near galaxy centres. |
| Document Type: | article in journal/newspaper |
| Language: | unknown |
| Relation: | https://eprints.ncl.ac.uk/310824 |
| Availability: | https://eprints.ncl.ac.uk/310824 |
| Accession Number: | edsbas.940EE353 |
| Database: | BASE |