Population Properties of Compact Objects from the Second LIGO-Virgo Gravitational-Wave Transient Catalog. (arXiv:2010.14533v2 [astro-ph.HE] UPDATED)
The <a href="http://arxiv.org/find/astro-ph/1/au:+Collaboration_LIGO_Scientific/0/1/0/all/0/1">LIGO Scientific Collaboration</a>, the <a href="http://arxiv.org/find/astro-ph/1/au:+Collaboration_Virgo/0/1/0/all/0/1">Virgo Collaboration</a>: <a href="http://arxiv.org/find/astro-ph/1/au:+Abbott_R/0/1/0/all/0/1">R. Abbott</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Abbott_T/0/1/0/all/0/1">T. D. Abbott</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Abraham_S/0/1/0/all/0/1">S. Abraham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Acernese_F/0/1/0/all/0/1">F. Acernese</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ackley_K/0/1/0/all/0/1">K. Ackley</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Adams_A/0/1/0/all/0/1">A. Adams</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Adams_C/0/1/0/all/0/1">C. Adams</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Adhikari_R/0/1/0/all/0/1">R. X. Adhikari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Adya_V/0/1/0/all/0/1">V. B. Adya</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Affeldt_C/0/1/0/all/0/1">C. Affeldt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Agathos_M/0/1/0/all/0/1">M. Agathos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Agatsuma_K/0/1/0/all/0/1">K. Agatsuma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aggarwal_N/0/1/0/all/0/1">N. Aggarwal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aguiar_O/0/1/0/all/0/1">O. D. Aguiar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aiello_L/0/1/0/all/0/1">L. Aiello</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ain_A/0/1/0/all/0/1">A. Ain</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ajith_P/0/1/0/all/0/1">P. Ajith</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Allen_G/0/1/0/all/0/1">G. Allen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Allocca_A/0/1/0/all/0/1">A. Allocca</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Altin_P/0/1/0/all/0/1">P. A. Altin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Amato_A/0/1/0/all/0/1">A. Amato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anand_S/0/1/0/all/0/1">S. Anand</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ananyeva_A/0/1/0/all/0/1">A. Ananyeva</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anderson_S/0/1/0/all/0/1">S. B. Anderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anderson_W/0/1/0/all/0/1">W. G. Anderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Angelova_S/0/1/0/all/0/1">S. V. Angelova</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ansoldi_S/0/1/0/all/0/1">S. Ansoldi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Antelis_J/0/1/0/all/0/1">J. M. Antelis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Antier_S/0/1/0/all/0/1">S. Antier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Appert_S/0/1/0/all/0/1">S. Appert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arai_K/0/1/0/all/0/1">K. Arai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Araya_M/0/1/0/all/0/1">M. C. Araya</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Areeda_J/0/1/0/all/0/1">J. S. Areeda</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arene_M/0/1/0/all/0/1">M. Ar&#xe8;ne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arnaud_N/0/1/0/all/0/1">N. Arnaud</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aronson_S/0/1/0/all/0/1">S. M. Aronson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arun_K/0/1/0/all/0/1">K. G. Arun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Asali_Y/0/1/0/all/0/1">Y. Asali</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ascenzi_S/0/1/0/all/0/1">S. Ascenzi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ashton_G/0/1/0/all/0/1">G. Ashton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aston_S/0/1/0/all/0/1">S. M. Aston</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Astone_P/0/1/0/all/0/1">P. Astone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aubin_F/0/1/0/all/0/1">F. Aubin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aufmuth_P/0/1/0/all/0/1">P. Aufmuth</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+AultONeal_K/0/1/0/all/0/1">K. AultONeal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Austin_C/0/1/0/all/0/1">C. Austin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Avendano_V/0/1/0/all/0/1">V. Avendano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Babak_S/0/1/0/all/0/1">S. Babak</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Badaracco_F/0/1/0/all/0/1">F. Badaracco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bader_M/0/1/0/all/0/1">M. K. M. Bader</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bae_S/0/1/0/all/0/1">S. Bae</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baer_A/0/1/0/all/0/1">A. M. Baer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bagnasco_S/0/1/0/all/0/1">S. Bagnasco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baird_J/0/1/0/all/0/1">J. Baird</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ball_M/0/1/0/all/0/1">M. Ball</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ballardin_G/0/1/0/all/0/1">G. Ballardin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ballmer_S/0/1/0/all/0/1">S. W. Ballmer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bals_A/0/1/0/all/0/1">A. Bals</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Balsamo_A/0/1/0/all/0/1">A. Balsamo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baltus_G/0/1/0/all/0/1">G. Baltus</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Banagiri_S/0/1/0/all/0/1">S. Banagiri</a>, et al. (1278 additional authors not shown)

We report on the population of the 47 compact binary mergers detected with a
false-alarm rate 1/yr in the second LIGO–Virgo Gravitational-Wave Transient
Catalog, GWTC-2. We observe several characteristics of the merging binary black
hole (BBH) population not discernible until now. First, we find that the
primary mass spectrum contains structure beyond a power-law with a sharp
high-mass cut-off; it is more consistent with a broken power law with a break
at $39.7^{+20.3}_{-9.1},M_odot$, or a power law with a Gaussian feature
peaking at $33.1^{+4.0}_{-5.6},M_odot$ (90% credible interval). While the
primary mass distribution must extend to $sim65,M_odot$ or beyond, only
$2.9^{+3.5}_{1.7}%$ of systems have primary masses greater than $45,M_odot$.
Second, we find that a fraction of BBH systems have component spins misaligned
with the orbital angular momentum, giving rise to precession of the orbital
plane. Moreover, 12% to 44% of BBH systems have spins tilted by more than
$90^circ$, giving rise to a negative effective inspiral spin parameter
$chi_mathrm{eff}$. Under the assumption that such systems can only be formed
by dynamical interactions, we infer that between 25% and 93% of BBH with
non-vanishing $|chi_mathrm{eff}| > 0.01$ are dynamically assembled. Third, we
estimate merger rates, finding $mathcal{R}_text{BBH} = 23.9^{+14.3}_{8.6}$
Gpc$^{-3}$ yr$^{-1}$ for BBH and $mathcal{R}_text{BNS}= 320^{+490}_{-240}$
Gpc$^{-3}$ yr$^{-1}$ for binary neutron stars. We find that the BBH rate likely
increases with redshift ($85%$ credibility), but not faster than the
star-formation rate ($86%$ credibility). Additionally, we examine recent
exceptional events in the context of our population models, finding that the
asymmetric masses of GW190412 and the high component masses of GW190521 are
consistent with our models, but the low secondary mass of GW190814 makes it an
outlier.

We report on the population of the 47 compact binary mergers detected with a
false-alarm rate 1/yr in the second LIGO–Virgo Gravitational-Wave Transient
Catalog, GWTC-2. We observe several characteristics of the merging binary black
hole (BBH) population not discernible until now. First, we find that the
primary mass spectrum contains structure beyond a power-law with a sharp
high-mass cut-off; it is more consistent with a broken power law with a break
at $39.7^{+20.3}_{-9.1},M_odot$, or a power law with a Gaussian feature
peaking at $33.1^{+4.0}_{-5.6},M_odot$ (90% credible interval). While the
primary mass distribution must extend to $sim65,M_odot$ or beyond, only
$2.9^{+3.5}_{1.7}%$ of systems have primary masses greater than $45,M_odot$.
Second, we find that a fraction of BBH systems have component spins misaligned
with the orbital angular momentum, giving rise to precession of the orbital
plane. Moreover, 12% to 44% of BBH systems have spins tilted by more than
$90^circ$, giving rise to a negative effective inspiral spin parameter
$chi_mathrm{eff}$. Under the assumption that such systems can only be formed
by dynamical interactions, we infer that between 25% and 93% of BBH with
non-vanishing $|chi_mathrm{eff}| > 0.01$ are dynamically assembled. Third, we
estimate merger rates, finding $mathcal{R}_text{BBH} = 23.9^{+14.3}_{8.6}$
Gpc$^{-3}$ yr$^{-1}$ for BBH and $mathcal{R}_text{BNS}= 320^{+490}_{-240}$
Gpc$^{-3}$ yr$^{-1}$ for binary neutron stars. We find that the BBH rate likely
increases with redshift ($85%$ credibility), but not faster than the
star-formation rate ($86%$ credibility). Additionally, we examine recent
exceptional events in the context of our population models, finding that the
asymmetric masses of GW190412 and the high component masses of GW190521 are
consistent with our models, but the low secondary mass of GW190814 makes it an
outlier.

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