Abstract Over a hundred gravitational-wave (GW) detections and candidates have been reported from the first three observing runs of the Advanced LIGO-Virgo-KAGRA (LVK) detectors. Among these, the most intriguing events are binary black hole mergers that result in a “lite” intermediate-mass black hole (IMBH) of ∼102M⊙, such as GW170502 and GW190521. In this study, we investigate 11 GW candidates from LVK’s third observing run with total detector-frame masses in the lite IMBH range. Using the Bayesian inference algorithmRIFT, we systematically analyze these candidates with three state-of-the-art waveform models that incorporate higher harmonics, which are crucial for resolving lite IMBHs in LVK data. For each candidate, we infer the premerger and postmerger black hole masses in the source frame, along with black hole spin projections across all three models. Under the assumption that these are binary black hole mergers, our analysis finds that five have a postmerger lite IMBH with masses ranging from 110 to 350M⊙with over 90% confidence interval. Additionally, we note that one of their premerger black holes is within the pair-instability supernova mass gap (60–120M⊙), and two premerger black holes are above the mass gap. Furthermore, we report discrepancies among the three waveform models in intrinsic parameters, with at least three GW candidates showing deviations beyond accepted statistical limits. While the astrophysical certainty of these candidates cannot be established, our study provides a foundation to probe the lite IMBH population that emerge within the low-frequency noise spectrum of LVK detectors.
more »
« less
A follow-up on intermediate-mass black hole candidates in the second LIGO–Virgo observing run with the Bayes Coherence Ratio
ABSTRACT The detection of an intermediate-mass black hole population (102–106 M⊙) will provide clues to their formation environments (e.g. discs of active galactic nuclei, globular clusters) and illuminate a potential pathway to produce supermassive black holes. Ground-based gravitational-wave detectors are sensitive to mergers that can form intermediate-mass black holes weighing up to ∼450 M⊙. However, ground-based detector data contain numerous incoherent short duration noise transients that can mimic the gravitational-wave signals from merging intermediate-mass black holes, limiting the sensitivity of searches. Here, we follow-up on binary black hole merger candidates using a ranking statistic that measures the coherence or incoherence of triggers in multiple-detector data. We use this statistic to rank candidate events, initially identified by all-sky search pipelines, with lab-frame total masses ≳ 55 M⊙ using data from LIGO’s second observing run. Our analysis does not yield evidence for new intermediate-mass black holes. However, we find support for eight stellar-mass binary black holes not reported in the first LIGO–Virgo gravitational wave transient catalogue GWTC-1, seven of which have been previously reported by other catalogues.
more »
« less
- Award ID(s):
- 1912594
- PAR ID:
- 10478099
- Publisher / Repository:
- Oxford Academic
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 516
- Issue:
- 4
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- 5309 to 5317
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract We report the observation of a coalescing compact binary with component masses 2.5–4.5M⊙and 1.2–2.0M⊙(all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO–Virgo–KAGRA detector network on 2023 May 29 by the LIGO Livingston observatory. The primary component of the source has a mass less than 5M⊙at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find the most probable interpretation of the source to be the coalescence of a neutron star with a black hole that has a mass between the most massive neutron stars and the least massive black holes observed in the Galaxy. We provisionally estimate a merger rate density of for compact binary coalescences with properties similar to the source of GW230529_181500; assuming that the source is a neutron star–black hole merger, GW230529_181500-like sources may make up the majority of neutron star–black hole coalescences. The discovery of this system implies an increase in the expected rate of neutron star–black hole mergers with electromagnetic counterparts and provides further evidence for compact objects existing within the purported lower mass gap.more » « less
-
Abstract Since 2015 the gravitational-wave observations of LIGO and Virgo have transformed our understanding of compact-object binaries. In the years to come, ground-based gravitational-wave observatories such as LIGO, Virgo, and their successors will increase in sensitivity, discovering thousands of stellar-mass binaries. In the 2030s, the space-based LISA will provide gravitational-wave observations of massive black holes binaries. Between the $$\sim 10$$ ∼ 10 –10 3 Hz band of ground-based observatories and the $$\sim 10^{-4}$$ ∼ 1 0 − 4 –10 − 1 Hz band of LISA lies the uncharted decihertz gravitational-wave band. We propose a Decihertz Observatory to study this frequency range, and to complement observations made by other detectors. Decihertz observatories are well suited to observation of intermediate-mass ( $$\sim 10^{2}$$ ∼ 1 0 2 –10 4 M ⊙ ) black holes; they will be able to detect stellar-mass binaries days to years before they merge, providing early warning of nearby binary neutron star mergers and measurements of the eccentricity of binary black holes, and they will enable new tests of general relativity and the Standard Model of particle physics. Here we summarise how a Decihertz Observatory could provide unique insights into how black holes form and evolve across cosmic time, improve prospects for both multimessenger astronomy and multiband gravitational-wave astronomy, and enable new probes of gravity, particle physics and cosmology.more » « less
-
Abstract We report the observation of gravitational waves from two binary black hole coalescences during the fourth observing run of the LIGO–Virgo–KAGRA detector network, GW241011 and GW241110. The sources of these two signals are characterized by rapid and precisely measured primary spins, nonnegligible spin–orbit misalignment, and unequal mass ratios between their constituent black holes. These properties are characteristic of binaries in which the more massive object was itself formed from a previous binary black hole merger and suggest that the sources of GW241011 and GW241110 may have formed in dense stellar environments in which repeated mergers can take place. As the third-loudest gravitational-wave event published to date, with a median network signal-to-noise ratio of 36.0, GW241011 furthermore yields stringent constraints on the Kerr nature of black holes, the multipolar structure of gravitational-wave generation, and the existence of ultralight bosons within the mass range 10−13–10−12eV.more » « less
-
This dataset contains the compact binary populations that were used in the Cosmic Explorer MPSAC White paper1 (submitted to the NSF MPSAC ngGW Subcommittee) and the accompanying technical paper2. Contents: 1. 1-year populations for binary black hole (BBH), binary neutron star (BNS), neutron star-black hole (NSBH), intermediate mass binary black hole (IMBBH), Population III (Pop 3) binary black holes and primordial black hole (PBH) mergers. It also contains the SNRs and measurement errors on intrinsic and extrinsic parameters calculated using gwbench3. 2. 1/4-year sub-population of BNS mergers for which errors on tidal parameters were calculated. 3. An ipython notebook (instructions.ipynb) that shows how the data can be used. References: 1. Evans, Matthew et al. Cosmic Explorer: A Submission to the NSF MPSAC ngGW Subcommittee (2023). arXiv: 2306.13745 [gr-qc]. 2. Gupta, Ish et al. Characterizing Gravitational Wave Detector Networks: From A# to Cosmic Explorer (2023). In preparation. 3. Borhanian, Ssohrab. GWBENCH: a novel Fisher information package for gravitational-wave benchmarking. Class. Quant. Grav. 38, 175014 (2021). arXiv: 2010.15202 [gr-qc].more » « less
An official website of the United States government

