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arXiv · 2303.05844

The Mass Distribution of Quasars in Optical Time-domain Surveys

Mouyuan Sun
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Abstract

The determination of supermassive black hole (SMBH) masses is the key to understanding the host galaxy build-up and the SMBH mass assembly histories. The SMBH masses of non-local quasars are frequently estimated via the single-epoch virial black-hole mass estimators, which may suffer from significant biases. Here we demonstrate a new approach to infer the mass distribution of SMBHs in quasars by modelling quasar UV/optical variability. Our inferred black hole masses are systematically smaller than the virial ones by $0.3\sim 0.6$ dex; the $\sim 0.3$ dex offsets are roughly consistent with the expected biases of the virial black-hole mass estimators. In the upcoming time-domain astronomy era, our methodology can be used to constrain the cosmic evolution of quasar mass distributions.

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Mouyuan Sun. 2023-03-10. The Mass Distribution of Quasars in Optical Time-domain Surveys. https://doi.org/10.1093/mnras%2Fstad740

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