An improved analysis of GW150914 using a fully spin-precessing waveform model

• Published in: arXiv.org 2016-06
• Main Authors: Adya, V B, Ajith, P, Allocca, A, Baker, P T, Barker, D, Bazzan, M, Bonnand, R, Boom, B A, Bozzi, A, Brinkmann, M, Bulik, T, Bustillo, J Calder'on, L Cerboni Baiardi, Chao, S, Cheeseboro, B D, Cheng, C, Cho, H S, Chung, S, Corsi, A, D'Antonio, S, De Laurentis, M, Edwards, M C, Factourovich, M, Farr, W M, Ferrante, I, Gonzalez Castro, J M, Gray, C, Guidi, G M, Hanna, C, Hardwick, T, Harms, J, Harry, G M, Heintze, M C, Heurs, M, Hughey, B, Isi, M, Kandhasamy, S, Kapadia, S J, Kasprzack, M, Kelley, D B, Kim, J, Kondrashov, V, Kozak, D B, Kringel, V, Leavey, S, Lenon, A, London, L T, Lorenzini, M, Lynch, R, Maksimovic, I, Marchesoni, F, Markosyan, A S, Masserot, A, Mazumder, N, McGuire, S C, Miller, A L, Morriss, S R, Nielsen, A B, Oppermann, P, Pankow, C, Paris, H R, Patrick, Z, Pfeiffer, H P, Piccinni, O J, Prasad, J, Price, L R, Principe, M, Privitera, S, Puncken, O, Punturo, M, Rapagnani, P, Razzano, M, Reed, C M, Rew, H, Roma, V J, Romanov, G, A R"udiger, Setyawati, Y, Shaltev, M, Sieniawska, M, Sintes, A M, Steinke, M, Stuver, A L, Sun, L, Taracchini, A, Taylor, R, Thomas, P, Thrane, E, M van Beuzekom, van Heijningen, J V, Vano-Vinuales, A, Vousden, W D, Wang, M, Wette, K, Wright, J L, H Yu, Zevin, M, Zhao, C, Zhou, Z, Zucker, M E
• Format: Article
• Language: English
• Subjects: Coalescing; Computer simulation; Conditional probability; Gravitational waves; Mathematical models; Parameter estimation; Relativity; Systematic errors
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1606.01210

This paper presents updated estimates of source parameters for GW150914, a binary black-hole coalescence event detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) on September 14, 2015 [1]. Reference presented parameter estimation [2] of the source using a 13-dimensional, phenomenological precessing-spin model (precessing IMRPhenom) and a 11-dimensional nonprecessing effective-one-body (EOB) model calibrated to numerical-relativity simulations, which forces spin alignment (nonprecessing EOBNR). Here we present new results that include a 15-dimensional precessing-spin waveform model (precessing EOBNR) developed within the EOB formalism. We find good agreement with the parameters estimated previously [2], and we quote updated component masses of \(35^{+5}_{-3}\mathrm{M}_\odot\) and \(30^{+3}_{-4}\mathrm{M}_\odot\) (where errors correspond to 90% symmetric credible intervals). We also present slightly tighter constraints on the dimensionless spin magnitudes of the two black holes, with a primary spin estimate \(0.65\) and a secondary spin estimate \(0.75\) at 90% probability. Reference [2] estimated the systematic parameter-extraction errors due to waveform-model uncertainty by combining the posterior probability densities of precessing IMRPhenom and nonprecessing EOBNR. Here we find that the two precessing-spin models are in closer agreement, suggesting that these systematic errors are smaller than previously quoted.