You Can't Always Get What You Want: The Impact of Prior Assumptions on Interpreting GW190412
Name
Zevin_2020_ApJL_899_L17.pdf
Description
Published version
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829.72 KB
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Unknown
Checksum (MD5)
82439ba36dee4f02e56493dff043df26
Author(s)
Zevin, Michael
Berry, Christopher P. L.
Coughlin, Scott
Chatziioannou, Katerina
Vitale, Salvatore
Date Issued
2020
Journal
Astrophysical Journal Letters
Publisher
American Astronomical Society
Version
Final published version
Abstract
© 2020. The American Astronomical Society. All rights reserved. GW190412 is the first observation of a black hole binary with definitively unequal masses. GW190412's mass asymmetry, along with the measured positive effective inspiral spin, allowed for inference of a component black hole spin: the primary black hole in the system was found to have a dimensionless spin magnitude between 0.17 and 0.59 (90% credible range). We investigate how the choice of priors for the spin magnitudes and tilts of the component black holes affect the robustness of parameter estimates for GW190412, and report Bayes factors across a suite of prior assumptions. Depending on the waveform family used to describe the signal, we find either marginal to moderate (2:1-6:1) or strong (≥20:1) support for the primary black hole being spinning compared to cases where only the secondary is allowed to have spin. We show how these choices influence parameter estimates, and find the asymmetric masses and positive effective inspiral spin of GW190412 to be qualitatively, but not quantitatively, robust to prior assumptions. Our results highlight the importance of both considering astrophysically motivated or population-based priors in interpreting observations and considering their relative support from the data.
MIT Department
LIGO (Observatory : Massachusetts Institute of Technology)
Massachusetts Institute of Technology. Department of Physics
MIT Kavli Institute for Astrophysics and Space Research
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.3847/2041-8213/aba8ef
