Signatures of Massive Black Hole Merger Host Galaxies from Cosmological Simulations I: Unique Galaxy Morphologies in Imaging

• DOI: 10.48550/arxiv.2308.03828
• Publication Date: 2023-01-01
• Authors: Jaeden Bardati; John J. Ruan; Daryl Haggard; Michael Tremmel
• Keywords: Gravitational wave sources; High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); FOS: Physical sciences; Galaxies; Astrophysics; Astrophysics - Astrophysics of Galaxies; QB460-466; Astrophysics of Galaxies (astro-ph.GA); Supermassive black holes; Radiative transfer simulations; N-body simulations; Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Cosmology and Nongalactic Astrophysics

Low-frequency gravitational wave experiments such as the Laser Interferometer Space Antenna and pulsar timing arrays are expected to detect individual massive black hole (MBH) binaries mergers. However, secure methods of identifying exact host galaxy each MBH merger amongst large number galaxies in localization region currently lacking. We investigate distinct morphological signatures galaxies, using Romulus25 cosmological simulation. produce mock telescope images 201 simulated hosting recent mergers, through stellar population synthesis dust radiative transfer. Based on comparisons mass- redshift-matched control samples, we show that combining multiple statistics via a linear discriminant analysis enables identification with accuracies increase chirp mass ratio. For mergers high masses (>10^8.2 Msun) ratios (>0.5), accuracy this approach reaches >80%, does not decline for at least >1 Gyr after numerical merger. argue these trends arise because most distinctive characteristics binary prominent classical bulges, rather than relatively short-lived disturbances from their preceding Since bulges formed though major they lead (and become permanent signposts for) have ratios. Our results suggest morphology can aid future