Galaxy Tomography with the Gravitational Wave Background from Supermassive Black Hole Binaries [Title version 1]
Year: 2026
Type: article
Abstract: The detection of a stochastic gravitational wave background by pulsar timing arrays suggests the presence of a supermassive black hole binary population. Although the observed spectrum generally aligns with predictions from orbital evolution driven by gravitational wave emission in circular orbits, there is a discernible preference for a turnover at the lowest observed frequencies. This turnover could indicate a significant hardening phase, transitioning from early environmental influences to later stages predominantly influenced by gravitational wave 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. By analyzing the NANOGrav 15-year data, we assess how the gravitational wave spectrum depends on the initial inner galactic profile prior to disruption by binary ejections, accounting for a range of initial binary eccentricities. Our findings suggest a parsec-scale galactic center density around $10^6\,M_\odot/\textrm{pc}^3$ across most of the parameter space, offering insights into the environmental effects on black hole evolution and combined matter density near galaxy centers.
Source: MPG.PuRe (Max Planck Society)
Authors: Chen, Y., Daniel, M., D'Orazio, D., Mitridate, A., Sagunski, L., Xue, X., Agazie, G., Baier, J., Baker, P., Bécsy, B., Blecha, L., Brazier, A., Brook, P., Burke-Spolaor, S., Burnette, R., Casey-Clyde, J., Charisi, M., Chatterjee, S., Cohen, T., Cordes, J., Cornish, N., Crawford, F., Cromartie, H., DeCesar, M., Demorest, P., Deng, H., Dey, L., Dolch, T., Ferrara, E., Fiore, W., Fonseca, E., Freedman, G., Gardiner, E., Gersbach, K., Glaser, J., Good, D., Gültekin, K., Hazboun, J., Jennings, R., Johnson, A., Kaplan, D., Kelley, L., Key, J., Laal, N., Lam, M., Lamb, W., Larsen, B., Lazio, T., Lewandowska, N., Liu, T., Luo, J., Lynch, R., Ma, C., Madison, D., McEwen, A., McKee, J., McLaughlin, M., Meyers, P., Mingarelli, C., Nice, D., Ocker, S., Olum, K., Pennucci, T., Petrov, P., Pol, N., Radovan, H., Ransom, S., Ray, P., Romano, J., Runnoe, J., Saffer, A., Sardesai, S., Schmitz, K., Siemens, X., Simon, J., Siwek, M., Fiscella, S., Stairs, I., Stinebring, D., Susobhanan , A., Swiggum, J., Taylor, J., Taylor, S., Turner, J., Unal, C., Vallisneri, M., van Haasteren, R., Verbiest, J., Vigeland, S., Witt, C., Wright, D., Young, O.
Institutions: University of Copenhagen, Goethe University Frankfurt, Space Telescope Science Institute, Deutsches Elektronen-Synchrotron DESY, University of Wisconsin–Milwaukee, Oregon State University, Widener University, University of Florida, Cornell University, West Virginia University, Vanderbilt University, New Mexico Institute of Mining and Technology, Montana State University, Franklin & Marshall College, National Academies of Sciences, Engineering, and Medicine, George Mason University, National Radio Astronomy Observatory, Hillsdale College, Eureka Scientific, University of California, Berkeley, University of Montana, University of Michigan, California Institute of Technology, University of Washington Bothell, Yale University, State University of New York at Oswego, University of Toronto, University of the Pacific, Union College, Lafayette College, Carnegie Institution for Science, Carnegie Observatories, Tufts University, Eötvös Loránd University, Texas Tech University, University of Puerto Rico-Mayaguez, United States Naval Research Laboratory, Naval Research Laboratory Space Science Division, University of Münster, University of Colorado Boulder, Harvard University, Center for Astrophysics Harvard & Smithsonian, Rochester Institute of Technology, University of British Columbia, Oberlin College, Max Planck Institute for Gravitational Physics, University of Central Florida, Northwestern University, Ben-Gurion University of the Negev, Adler Planetarium, Middle East Technical University, Boğaziçi University, Feza Gürsey Institute, Jet Propulsion Laboratory, National Academy of Sciences
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, Gordon and Betty Moore Foundation, Research Corporation for Science Advancement, Vanderbilt University, California Institute of Technology, Texas Tech University, Canadian Institute for Advanced Research, University of Central Florida, Villum Fonden, Oregon State University, Centres de Recerca de Catalunya, European Commission, Deutsche Forschungsgemeinschaft, Generalitat de Catalunya, University of Toronto, Israel Academy of Sciences and Humanities, Council for Higher Education, Eötvös Loránd Tudományegyetem, Institut de Física d'Altes Energies, Jet Propulsion Laboratory, Horizon 2020 Framework Programme, College of Science, Oregon State University, Natural Sciences and Engineering Research Council of Canada, Science and Technology Facilities Council, Agencia Estatal de Investigación, Office of Naval Research
Awards: NANOGrav@UPRM: Growing and Characterizing the NANOGrav Gravitational-Wave Detector, The First Multi-Messenger Study of Supermassive Black Hole Growth, CAREER: Unveiling the Nanohertz GW Discovery Landscape by Broadening Participation In Multi-Messenger Astrophysics, G118299772, G1299739531, NANOGrav Physics Frontier Center, G201248631, G2500807902, G2536870102, Enabling multi-messenger science with pulsar timing arrays, G2676722403, CAREER: More Accurate Galaxy Merger Rates to Propel Studies of Gravitational Waves and Star Formation in Galaxy Mergers, AccelNet-Implementation: The International Pulsar Timing Array, WOU-MMA: Probing Supermassive Binary Black Holes with Pulsar Timing Arrays, G337820874, G3480869486, G3492272913, G3648211085, G3782671888, G432818845, G4492706539, Astrophysics at the University of Birmingham - Consolidated grant 2022-2025, G4961910479, Collaborative Research: An Empirical Blueprint for the Gravitational-Wave Background, RII Track-1: Gravitational Wave Astronomy and the Appalachian Freshwater Initiative, Graduate Research Fellowship Program (GRFP), Management and Operations of the Arecibo Observatory, G5429681523, Improving NANOGrav Gravitational Wave Detection, G5759873967, Collaborative research: Completing the most sensitive low-frequency survey for radio pulsars and transients, The Construction of a Pulsar Interstellar Medium Array Detector, G6671297155, G7084143925, EXC 2121: Quantum Universe, G7484881787, WoU-MMA: Multi-messenger Titans: Probing The Dynamics & Environments Of Supermassive Binary Black Holes, The NANOGrav Physics Frontiers Center, G830101876, Collaborative Research: The Impacts of Massive Black Hole Formation and Evolution Pathways on Gravitational Wave Sources, Kavli Institute for Theoretical Physics, G8508037660, G8733234872
OpenAlex ID: W7140956271