中国科学院云南天文台特邀学术报告

YNAO Colloquium 2025

 第15期

Topic：Testing Black-Hole Formation with LIGO: Evidence for a Bimodal Black-Hole Mass Distribution

Speaker：Prof. Philipp Podsiadlowski

Affiliation：London Centre for Stellar Astrophysics and University of Oxford

Language：English

Time：Thursday, Sep 11th, 2025, 10:00–12:00 AM

Location：Lecture Theatre, 2nd Floor, Building 7

Tencent Meeting ID：757-399-428

Abstract：

～～～～～～～～～～～～～

There has been dramatic progress in recent years in our understanding of core-collapse supernovae. This, for the first time, has allowed us to connect supernova progenitors with their supernova explosions and their remnants. Among other things, this makes unique predictions about the black-hole mass spectrum which can be tested through detections of gravitational waves by LIGO caused by the merger of two black holes. Specifically, it predicts a peak in the mass distribution around 9 solar masses. I will explain the origin of this peak and show that it is only weakly dependent on metallicity. This leads to a peak in the predicted LIGO chirp-mass distribution around 8 solar masses and a gap/deficiency of systems just beyond. Using the binary population synthesis code COMPAS, we have made predictions for the rates LIGO should observe. The LIGO/Virgo/KAGRA just a few weeks ago released the results from the O4a LIGO run, bringing the number of detected black-hole mergers to 158. The observed chirp-mass distribution now shows a peak-gap structure that is in striking agreement with our predictions and rules out other commonly used black-hole formation prescriptions. This confirms our basic understanding of late stellar evolution and key aspects of the core-collapse mechanism. It also shows that, as predicted, black holes are much harder to form in binaries than has often been assumed in the literature. This explains, e.g., the lack of Be X-ray binaries containing black holes. I will discuss this and other implications for modeling black-hole binary systems.

～～～～～～～～～～～～～

Speaker：

Prof. Philipp Podsiadlowski is a Professor of Physics at the University of Oxford. He received his Ph.D at the Massachusetts Institute of Technology in 1989. He is a broad-profile specialist working in stellar evolution theory and its applications to binary stellar evolution, supernovae, gamma-ray bursts, galaxy evolution, planet formation, and aLIGO gravitational-wave sources. He has published more than 170 papers in refereed journals (including 23 in Nature and Science). Prof. Podsiadlowski was awarded the Humboldt Research Prize by the German Humboldt Foundation in recognition of his “Life’s Research and Contribution to Teaching”.

主办：中国科学院云南天文台学术委员会

联系人：葛宏伟