Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO

Gonzalo Morrás; José Francisco Nuño Siles; Juan García-Bellido; Ester Ruiz Morales; Alexis Menéndez-Vázquez; Christos Karathanasis; Katarina Martinovic; Khun Sang Phukon; Sebastien Clesse; Mario Martínez; Mairi Sakellariadou

doi:10.1016/j.dark.2023.101285

Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO

Gonzalo Morrás, José Francisco Nuño Siles, Juan García-Bellido^*, Ester Ruiz Morales, Alexis Menéndez-Vázquez, Christos Karathanasis, Katarina Martinovic, Khun Sang Phukon, Sebastien Clesse, Mario Martínez, Mairi Sakellariadou

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

17 Citations (Scopus)

Abstract

We perform an exhaustive follow-up analysis of a subsolar-mass (SSM) gravitational wave (GW) candidate reported by Phukon et al. from the second observing run of Advanced LIGO. This candidate has a reported signal-to-noise ratio (SNR) of 8.6 and false alarm rate of 0.41 yr which are too low to claim a clear gravitational-wave origin. When improving on the search by using more accurate waveforms, extending the frequency range from 45 Hz down to 20 Hz, and removing a prominent blip glitch, we find that the posterior distribution of the network SNR lies mostly below the search value, with the 90% confidence interval being 7.94_−1.05^+0.70. Assuming that the origin of the signal is a compact binary coalescence (CBC), the secondary component is m₂=0.76_−0.14^+0.50M_⊙, with m₂<1M_⊙ at 84% confidence level, suggesting an unexpectedly light neutron star or a black hole of primordial or exotic origin. The primary mass would be m₁=4.71_−2.18^+1.57M_⊙, likely in the hypothesized lower mass gap and the luminosity distance is measured to be D_L=124₋₄₈⁺⁸²Mpc. We then probe the CBC origin hypothesis by performing the signal coherence tests, obtaining a log Bayes factor of 4.96±0.13 for the coherent vs. incoherent hypothesis. We demonstrate the capability of performing a parameter estimation follow-up on real data for an SSM candidate with moderate SNR. The improved sensitivity of O4 and subsequent LIGO-Virgo-KAGRA observing runs could make it possible to observe similar signals, if present, with a higher SNR and more precise measurement of the parameters of the binary.

Original language	English
Article number	101285
Journal	Physics of the Dark Universe
Volume	42
Early online date	25 Jul 2023
DOIs	https://doi.org/10.1016/j.dark.2023.101285
Publication status	Published - Dec 2023

Keywords

Dark matter
Gravitational waves
Primordial black holes

Access to Document

10.1016/j.dark.2023.101285

Cite this

Morrás, G., Nuño Siles, J. F., García-Bellido, J., Ruiz Morales, E., Menéndez-Vázquez, A., Karathanasis, C., Martinovic, K., Phukon, K. S., Clesse, S., Martínez, M., & Sakellariadou, M. (2023). Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO. Physics of the Dark Universe, 42, Article 101285. https://doi.org/10.1016/j.dark.2023.101285

@article{d40d32fe81334907838201e2a1eafd6f,

title = "Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO",

abstract = "We perform an exhaustive follow-up analysis of a subsolar-mass (SSM) gravitational wave (GW) candidate reported by Phukon et al. from the second observing run of Advanced LIGO. This candidate has a reported signal-to-noise ratio (SNR) of 8.6 and false alarm rate of 0.41 yr which are too low to claim a clear gravitational-wave origin. When improving on the search by using more accurate waveforms, extending the frequency range from 45 Hz down to 20 Hz, and removing a prominent blip glitch, we find that the posterior distribution of the network SNR lies mostly below the search value, with the 90% confidence interval being 7.94−1.05+0.70. Assuming that the origin of the signal is a compact binary coalescence (CBC), the secondary component is m2=0.76−0.14+0.50M⊙, with m2<1M⊙ at 84% confidence level, suggesting an unexpectedly light neutron star or a black hole of primordial or exotic origin. The primary mass would be m1=4.71−2.18+1.57M⊙, likely in the hypothesized lower mass gap and the luminosity distance is measured to be DL=124−48+82Mpc. We then probe the CBC origin hypothesis by performing the signal coherence tests, obtaining a log Bayes factor of 4.96±0.13 for the coherent vs. incoherent hypothesis. We demonstrate the capability of performing a parameter estimation follow-up on real data for an SSM candidate with moderate SNR. The improved sensitivity of O4 and subsequent LIGO-Virgo-KAGRA observing runs could make it possible to observe similar signals, if present, with a higher SNR and more precise measurement of the parameters of the binary.",

keywords = "Dark matter, Gravitational waves, Primordial black holes",

author = "Gonzalo Morr{\'a}s and {Nu{\~n}o Siles}, {Jos{\'e} Francisco} and Juan Garc{\'i}a-Bellido and {Ruiz Morales}, Ester and Alexis Men{\'e}ndez-V{\'a}zquez and Christos Karathanasis and Katarina Martinovic and Phukon, {Khun Sang} and Sebastien Clesse and Mario Mart{\'i}nez and Mairi Sakellariadou",

note = "Funding Information: The authors thank Patrick Meyers and Walter Del Pozzo for their helpful comments and discussions as reviewers of this paper in LIGO and Virgo respectively as well as Juan Calder{\'o}n Bustillo and Geraint Pratten for their constructive feedback. We thank the anonymous referee for their careful reading of our manuscript and their many insightful comments and suggestions. This work is partially supported by the Spanish grants PID2020-113701GB-I00, PID2021-123012NB-C43 [MICINN-FEDER], and the Centro de Excelencia Severo Ochoa ProgramCEX2020-001007-S through IFT, some of which include ERDF funds from the European Union. S.C. acknowledges support from the Francqui Foundation through a Starting Grant. K.M. is supported by King's College London, UK through a Postgraduate International Scholarship. M.S. is supported in part by the Science and Technology Facility Council (STFC), United Kingdom, under the research grant ST/P000258/1. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya, Spain. We acknowledge the use of IUCAA LDG cluster Sarathi for the computational/numerical work. This material is based upon work supported by NSF's LIGO Laboratory which is a major facility fully funded by the National Science Foundation, United States. Funding Information: The authors thank Patrick Meyers and Walter Del Pozzo for their helpful comments and discussions as reviewers of this paper in LIGO and Virgo respectively as well as Juan Calder{\'o}n Bustillo and Geraint Pratten for their constructive feedback. We thank the anonymous referee for their careful reading of our manuscript and their many insightful comments and suggestions. This work is partially supported by the Spanish grants PID2020-113701GB-I00, PID2021-123012NB-C43 [MICINN-FEDER], and the Centro de Excelencia Severo Ochoa Program CEX2020-001007-S through IFT, some of which include ERDF funds from the European Union. S.C. acknowledges support from the Francqui Foundation through a Starting Grant. K.M. is supported by King{\textquoteright}s College London, UK through a Postgraduate International Scholarship. M.S. is supported in part by the Science and Technology Facility Council (STFC), United Kingdom , under the research grant ST/P000258/1 . IFAE is partially funded by the CERCA program of the Generalitat de Catalunya, Spain . We acknowledge the use of IUCAA LDG cluster Sarathi for the computational/numerical work. This material is based upon work supported by NSF{\textquoteright}s LIGO Laboratory which is a major facility fully funded by the National Science Foundation, United States . Publisher Copyright: {\textcopyright} 2023 Elsevier B.V.",

year = "2023",

month = dec,

doi = "10.1016/j.dark.2023.101285",

language = "English",

volume = "42",

journal = "Physics of the Dark Universe",

issn = "2212-6864",

publisher = "Elsevier BV",

}

Morrás, G, Nuño Siles, JF, García-Bellido, J, Ruiz Morales, E, Menéndez-Vázquez, A, Karathanasis, C, Martinovic, K, Phukon, KS, Clesse, S, Martínez, M & Sakellariadou, M 2023, 'Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO', Physics of the Dark Universe, vol. 42, 101285. https://doi.org/10.1016/j.dark.2023.101285

TY - JOUR

T1 - Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO

AU - Morrás, Gonzalo

AU - Nuño Siles, José Francisco

AU - García-Bellido, Juan

AU - Ruiz Morales, Ester

AU - Menéndez-Vázquez, Alexis

AU - Karathanasis, Christos

AU - Martinovic, Katarina

AU - Phukon, Khun Sang

AU - Clesse, Sebastien

AU - Martínez, Mario

AU - Sakellariadou, Mairi

N1 - Funding Information: The authors thank Patrick Meyers and Walter Del Pozzo for their helpful comments and discussions as reviewers of this paper in LIGO and Virgo respectively as well as Juan Calderón Bustillo and Geraint Pratten for their constructive feedback. We thank the anonymous referee for their careful reading of our manuscript and their many insightful comments and suggestions. This work is partially supported by the Spanish grants PID2020-113701GB-I00, PID2021-123012NB-C43 [MICINN-FEDER], and the Centro de Excelencia Severo Ochoa ProgramCEX2020-001007-S through IFT, some of which include ERDF funds from the European Union. S.C. acknowledges support from the Francqui Foundation through a Starting Grant. K.M. is supported by King's College London, UK through a Postgraduate International Scholarship. M.S. is supported in part by the Science and Technology Facility Council (STFC), United Kingdom, under the research grant ST/P000258/1. IFAE is partially funded by the CERCA program of the Generalitat de Catalunya, Spain. We acknowledge the use of IUCAA LDG cluster Sarathi for the computational/numerical work. This material is based upon work supported by NSF's LIGO Laboratory which is a major facility fully funded by the National Science Foundation, United States. Funding Information: The authors thank Patrick Meyers and Walter Del Pozzo for their helpful comments and discussions as reviewers of this paper in LIGO and Virgo respectively as well as Juan Calderón Bustillo and Geraint Pratten for their constructive feedback. We thank the anonymous referee for their careful reading of our manuscript and their many insightful comments and suggestions. This work is partially supported by the Spanish grants PID2020-113701GB-I00, PID2021-123012NB-C43 [MICINN-FEDER], and the Centro de Excelencia Severo Ochoa Program CEX2020-001007-S through IFT, some of which include ERDF funds from the European Union. S.C. acknowledges support from the Francqui Foundation through a Starting Grant. K.M. is supported by King’s College London, UK through a Postgraduate International Scholarship. M.S. is supported in part by the Science and Technology Facility Council (STFC), United Kingdom , under the research grant ST/P000258/1 . IFAE is partially funded by the CERCA program of the Generalitat de Catalunya, Spain . We acknowledge the use of IUCAA LDG cluster Sarathi for the computational/numerical work. This material is based upon work supported by NSF’s LIGO Laboratory which is a major facility fully funded by the National Science Foundation, United States . Publisher Copyright: © 2023 Elsevier B.V.

PY - 2023/12

Y1 - 2023/12

N2 - We perform an exhaustive follow-up analysis of a subsolar-mass (SSM) gravitational wave (GW) candidate reported by Phukon et al. from the second observing run of Advanced LIGO. This candidate has a reported signal-to-noise ratio (SNR) of 8.6 and false alarm rate of 0.41 yr which are too low to claim a clear gravitational-wave origin. When improving on the search by using more accurate waveforms, extending the frequency range from 45 Hz down to 20 Hz, and removing a prominent blip glitch, we find that the posterior distribution of the network SNR lies mostly below the search value, with the 90% confidence interval being 7.94−1.05+0.70. Assuming that the origin of the signal is a compact binary coalescence (CBC), the secondary component is m2=0.76−0.14+0.50M⊙, with m2<1M⊙ at 84% confidence level, suggesting an unexpectedly light neutron star or a black hole of primordial or exotic origin. The primary mass would be m1=4.71−2.18+1.57M⊙, likely in the hypothesized lower mass gap and the luminosity distance is measured to be DL=124−48+82Mpc. We then probe the CBC origin hypothesis by performing the signal coherence tests, obtaining a log Bayes factor of 4.96±0.13 for the coherent vs. incoherent hypothesis. We demonstrate the capability of performing a parameter estimation follow-up on real data for an SSM candidate with moderate SNR. The improved sensitivity of O4 and subsequent LIGO-Virgo-KAGRA observing runs could make it possible to observe similar signals, if present, with a higher SNR and more precise measurement of the parameters of the binary.

AB - We perform an exhaustive follow-up analysis of a subsolar-mass (SSM) gravitational wave (GW) candidate reported by Phukon et al. from the second observing run of Advanced LIGO. This candidate has a reported signal-to-noise ratio (SNR) of 8.6 and false alarm rate of 0.41 yr which are too low to claim a clear gravitational-wave origin. When improving on the search by using more accurate waveforms, extending the frequency range from 45 Hz down to 20 Hz, and removing a prominent blip glitch, we find that the posterior distribution of the network SNR lies mostly below the search value, with the 90% confidence interval being 7.94−1.05+0.70. Assuming that the origin of the signal is a compact binary coalescence (CBC), the secondary component is m2=0.76−0.14+0.50M⊙, with m2<1M⊙ at 84% confidence level, suggesting an unexpectedly light neutron star or a black hole of primordial or exotic origin. The primary mass would be m1=4.71−2.18+1.57M⊙, likely in the hypothesized lower mass gap and the luminosity distance is measured to be DL=124−48+82Mpc. We then probe the CBC origin hypothesis by performing the signal coherence tests, obtaining a log Bayes factor of 4.96±0.13 for the coherent vs. incoherent hypothesis. We demonstrate the capability of performing a parameter estimation follow-up on real data for an SSM candidate with moderate SNR. The improved sensitivity of O4 and subsequent LIGO-Virgo-KAGRA observing runs could make it possible to observe similar signals, if present, with a higher SNR and more precise measurement of the parameters of the binary.

KW - Dark matter

KW - Gravitational waves

KW - Primordial black holes

UR - http://www.scopus.com/inward/record.url?scp=85166014676&partnerID=8YFLogxK

U2 - 10.1016/j.dark.2023.101285

DO - 10.1016/j.dark.2023.101285

M3 - Article

AN - SCOPUS:85166014676

SN - 2212-6864

VL - 42

JO - Physics of the Dark Universe

JF - Physics of the Dark Universe

M1 - 101285

ER -

Analysis of a subsolar-mass compact binary candidate from the second observing run of Advanced LIGO

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this