All Outputs (6)

Is GW190521 the merger of black holes from the first stellar generations? (2020)
Journal Article
Farrell, E., Groh, J. H., Hirschi, R., Murphy, L., Kaiser, E., Ekström, S., …Meynet, G. (2021). Is GW190521 the merger of black holes from the first stellar generations?. Monthly Notices of the Royal Astronomical Society, 502(1), L40-L44. https://doi.org/10.1093/mnrasl/slaa196

GW190521 challenges our understanding of the late-stage evolution of massive stars and the effects of the pair-instability in particular. We discuss the possibility that stars at low or zero metallicity could retain most of their hydrogen envelope un... Read More about Is GW190521 the merger of black holes from the first stellar generations?.

Grids of stellar models with rotation: V. Models from 1.7 to 120 Msun at zero metallicity (2020)
Journal Article
Murphy, L. J., Groh, J. H., Ekström, S., Meynet, G., Pezzotti, C., Georgy, C., …Martinet, S. (2021). Grids of stellar models with rotation: V. Models from 1.7 to 120 Msun at zero metallicity. Monthly Notices of the Royal Astronomical Society, 501(2), 2745-2763. https://doi.org/10.1093/mnras/staa3803

Understanding the nature of the first stars is key to understanding the early universe. With new facilities such as JWST we may soon have the first observations of the earliest stellar populations, but to understand these observations we require deta... Read More about Grids of stellar models with rotation: V. Models from 1.7 to 120 Msun at zero metallicity.

Nucleosynthesis in early rotating massive stars and chemical composition of CEMP stars (2020)
Journal Article
Choplin, A., & Hirschi, R. (2020). Nucleosynthesis in early rotating massive stars and chemical composition of CEMP stars. Journal of Physics: Conference Series, 1668(1), Article 012006. https://doi.org/10.1088/1742-6596/1668/1/012006

The first massive stars triggered the onset of chemical evolution by releasing the first metals (elements heavier than helium) in the Universe. The nature of these stars and how the early chemical enrichment took place is still largely unknown. Rotat... Read More about Nucleosynthesis in early rotating massive stars and chemical composition of CEMP stars.

Relative Importance of Convective Uncertainties in Massive Stars (2020)
Journal Article
Kaiser, E. A., Hirschi, R., Arnett, W. D., Georgy, C., Scott, L. J. A., & Cristini, A. (2020). Relative Importance of Convective Uncertainties in Massive Stars. Monthly Notices of the Royal Astronomical Society, 496(2), 1967-1989. https://doi.org/10.1093/mnras/staa1595

In this work, we investigate the impact of uncertainties due to convective boundary mixing (CBM), commonly called ‘overshoot’, namely the boundary location and the amount of mixing at the convective boundary, on stellar structure and evolution. For t... Read More about Relative Importance of Convective Uncertainties in Massive Stars.

Evolutionary roads leading to low effective spins, high black hole masses, and O1/O2 rates for LIGO/Virgo binary black holes (2020)
Journal Article
Belczynski, K., Klencki, J., Fields, C., Olejak, A., Berti, E., Meynet, G., …Lasota, J. (2020). Evolutionary roads leading to low effective spins, high black hole masses, and O1/O2 rates for LIGO/Virgo binary black holes. Astronomy and Astrophysics, 636, Article A104. https://doi.org/10.1051/0004-6361/201936528

All ten LIGO/Virgo binary black hole (BH-BH) coalescences reported following the O1/O2 runs have near-zero effective spins. There are only three potential explanations for this. If the BH spin magnitudes are large, then: (i) either both BH spin vecto... Read More about Evolutionary roads leading to low effective spins, high black hole masses, and O1/O2 rates for LIGO/Virgo binary black holes.

The Formation of a 70 M ? Black Hole at High Metallicity (2020)
Journal Article
Hirschi. (2020). The Formation of a 70 M ? Black Hole at High Metallicity. Astrophysical Journal, 113 -113. https://doi.org/10.3847/1538-4357/ab6d77

A 70 black hole (BH) was discovered in the Milky Way disk in a long-period detached binary system (LB-1) with a high-metallicity 8 B star companion. Current consensus on the formation of BHs from high-metallicity stars limits the BH mass to be below... Read More about The Formation of a 70 M ? Black Hole at High Metallicity.