A Caltech Library Service

On the properties of the massive binary black hole merger GW170729

Chatziioannou, Katerina and Barkett, Kevin and Blackman, Jonathan and Giesler, Matthew and Hemberger, Daniel and Scheel, Mark A. and Szilágyi, Béla and Teukolsky, Saul A. (2019) On the properties of the massive binary black hole merger GW170729. Physical Review D, 100 (10). Art. No. 104015. ISSN 2470-0010.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present a detailed investigation into the properties of GW170729, the gravitational wave with the most massive and distant source confirmed to date. We employ an extensive set of waveform models, including new improved models that incorporate the effect of higher-order waveform modes which are particularly important for massive systems. We find no indication of spin-precession, but the inclusion of higher-order modes in the models results in an improved estimate for the mass ratio of (0.3–0.8) at the 90% credible level. Our updated measurement excludes equal masses at that level. We also find that models with higher-order modes lead to the data being more consistent with a smaller effective spin, with the probability that the effective spin is greater than zero being reduced from 99% to 94%. The 90% credible interval for the effective spin parameter is now (−0.01−0.50). Additionally, the recovered signal-to-noise ratio increases by ∼0.3 units compared to analyses without higher-order modes; the overall Bayes factor in favor of the presence of higher-order modes in the data is 5.1∶1. We study the effect of common spin priors on the derived spin and mass measurements, and observe small shifts in the spins, while the masses remain unaffected. We argue that our conclusions are robust against systematic errors in the waveform models. We also compare the above waveform-based analysis which employs compact-binary waveform models to a more flexible wavelet- and chirplet-based analysis. We find consistency between the two, with overlaps of ∼0.9, typical of what is expected from simulations of signals similar to GW170729, confirming that the data are well-described by the existing waveform models. Finally, we study the possibility that the primary component of GW170729 was the remnant of a past merger of two black holes and find this scenario to be indistinguishable from the standard formation scenario.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Chatziioannou, Katerina0000-0002-5833-413X
Blackman, Jonathan0000-0002-7113-0289
Giesler, Matthew0000-0003-2300-893X
Teukolsky, Saul A.0000-0001-9765-4526
Additional Information:© 2019 American Physical Society. Received 18 March 2019; published 7 November 2019. We thank Christopher Berry, Thomas Dent, Tristano DiGirolamo, Bhooshan Gadre, Roland Haas, Nathan Johnson-McDaniel, Riccardo Sturani, and Aaron Zimmerman for helpful comments and suggestions. This research has made use of data, software and/or web tools obtained from the Gravitational Wave Open Science Center (, a service of LIGO Laboratory, the LIGO Scientific Collaboration and the Virgo Collaboration. LIGO is funded by the U.S. National Science Foundation. Virgo is funded by the French Centre National de Recherche Scientifique (CNRS), the Italian Istituto Nazionale della Fisica Nucleare (INFN) and the Dutch Nikhef, with contributions by Polish and Hungarian institutes. The Flatiron Institute is supported by the Simons Foundation. J. C. B. acknowledges support from Australian Research Council Discovery Project DP180103155. C. J. H, K. K. Y. N and S. V. acknowledges the support of the National Science Foundation and the LIGO Laboratory. LIGO was constructed by the California Institute of Technology and Massachusetts Institute of Technology with funding from the National Science Foundation and operates under cooperative agreement PHY-1764464. M. H. was supported by Science and Technology Facilities Council (STFC) Grant No. ST/L000962/1 and European Research Council Consolidator Grant No. 647839. Parts of this research were conducted by the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav), through Project No. CE170100004. R. O. S. and J. L. are supported by National Science Foundation (NSF) Grants No. PHY-1707965 and No. PHY-1607520. P. S. acknowledges support from the NWO Veni grant no. 680-47-460 and the Science and Technology Facilities Council Grant No. ST/N000633/1. M. H. acknowledges support from the Swiss National Science Foundation (SNSF) Grant No. IZCOZ0_177057. L. S. was supported by the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology (2018QNRC001), and partially supported by the National Science Foundation of China (11721303), and XDB23010200. The GT authors gratefully acknowledge the NSF for financial support from Grants No. PHY 1806580, No. PHY 1809572, and No. TG-PHY120016. Computational resources were provided by XSEDE and the Georgia Tech Cygnus Cluster. The RIT authors gratefully acknowledge the NSF for financial support from Grants No. PHY-1607520, No. PHY-1707946, No. ACI-1550436, No. AST-1516150, No. ACI-1516125, No. PHY-1726215. This work used the Extreme Science and Engineering Discovery Environment (XSEDE) [allocation TG-PHY060027N], which is supported by NSF grant No. ACI-1548562. Computational resources were also provided by the NewHorizons, BlueSky Clusters, and Green Prairies at the Rochester Institute of Technology, which were supported by NSF grants No. PHY-0722703, No. DMS-0820923, No. AST-1028087, No. PHY-1229173, and No. PHY-1726215. The SXS authors at Caltech acknowledge the Sherman Fairchild Foundation, and NSF Grants No. PHY-1708212 and No. PHY-1708213. G. L., N. A., and A. G. are supported by NSF Grants No. PHY-1606522, No. PHY-1654359, No. PHY-1654359. Computations were done using the orca cluster supported in part by PHY-1429873 and by Cal State Fullerton. A. G. is also supported in part by Nancy Goodhue-McWilliams. The authors are grateful for computational resources provided by the LIGO Laboratory and supported by National Science Foundation Grants No. PHY-0757058 and No. PHY-0823459. Some of the computational work for this manuscript was also carried out on the computer cluster vULCAN at the Max Planck Institute for Gravitational Physics in Potsdam. Plots have been made with matplotlib [107] and corner [108].
Group:LIGO, TAPIR, Astronomy Department
Funding AgencyGrant Number
Centre National de Recherche Scientifique (CNRS)UNSPECIFIED
Istituto Nazionale di Fisica Nucleare (INFN)UNSPECIFIED
Australian Research CouncilDP180103155
Science and Technology Facilities Council (STFC)ST/L000962/1
European Research Council (ERC)647839
Australian Research CouncilCE170100004
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)680-47-460
Science and Technology Facilities Council (STFC)ST/N000633/1
Swiss National Science Foundation (SNSF)IZCOZ0 177057
China Association for Science and Technology2018QNRC001
National Natural Science Foundation of China11721303
National Natural Science Foundation of ChinaXDB23010200
NSFACI- 1550436
Sherman Fairchild FoundationUNSPECIFIED
California State University, FullertonUNSPECIFIED
Nancy Goodhue-McWilliamsUNSPECIFIED
Issue or Number:10
Record Number:CaltechAUTHORS:20190821-153756552
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:98090
Deposited By: Tony Diaz
Deposited On:21 Aug 2019 22:58
Last Modified:22 Jul 2020 22:00

Repository Staff Only: item control page