The more accurately the metal-dependent star formation rate is modeled, the larger the predicted excess of binary black hole mergers
As the number of gravitational wave detections grows, the merger rate of binary black holes (BBHs) can help us to constrain their formation, the properties of their progenitors, and their birth environment. Here, we aim to address the impact of the metal-dependent star formation rate (SFR) on the BB...
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| Main Authors: | , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
May 2025
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| In: |
Astronomy and astrophysics
Year: 2025, Volume: 698, Pages: 1-14 |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/202452757 |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.1051/0004-6361/202452757 Verlag, kostenfrei, Volltext: https://www.aanda.org/articles/aa/abs/2025/06/aa52757-24/aa52757-24.html 
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| Author Notes: | Cecilia Sgalletta, Michela Mapelli, Lumen Boco, Filippo Santoliquido, M. Celeste Artale, Giuliano Iorio, Andrea Lapi, and Mario Spera |
| Summary: | As the number of gravitational wave detections grows, the merger rate of binary black holes (BBHs) can help us to constrain their formation, the properties of their progenitors, and their birth environment. Here, we aim to address the impact of the metal-dependent star formation rate (SFR) on the BBH merger rate. To this end, we have developed a fully data-driven approach to model the metal-dependent SFR and coupled it to BBH evolution. We have adopted the most up-to-date scaling relations, based on recent observational results, and we have studied how the BBH merger rate density varies over a wide grid of galaxy and binary evolution parameters. Our results show that including a realistic metal-dependent SFR evolution yields a value of the merger rate density that is too high compared to the one inferred from gravitational wave data. Moreover, variations in the SFR in low-mass galaxies (M* ≲ 10 8 M⊙) do not contribute more than a factor ∼2 to the overall merger rate density at redshift z = 0. These results suggest that the discrepancy between the BBH merger rate density inferred from data and theoretical models is not caused by approximations in the treatment of the metal-dependent SFR, but rather stems from stellar evolution models and/or BBH formation channels. |
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| Item Description: | Online veröffentlicht: 11. Juni 2025 Gesehen am 27.10.2025 |
| Physical Description: | Online Resource |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/202452757 |