Expected properties of the first gravitational wave signal detected with pulsar timing arrays

By P. Rosado, A. Sesana, Jonathan R. Gair. 2015

175 citations recorded by the source corpus.

In this paper we attempt to investigate the nature of the first gravitational wave (GW) signal to be detected by pulsar timing arrays (PTAs): will it be an individual, resolved supermassive black hole binary (SBHB), or a stochastic background made by the superposition of GWs produced by an ensemble of SBHBs? To address this issue, we analyse a broad set of simulations of the cosmological population of SBHBs, that cover the entire parameter space allowed by current electromagnetic observations in an unbiased way. For each simulation, we construct the expected GW signal and identify the loudest individual sources. We then employ appropriate detection statistics to evaluate the relative probability of detecting each type of source as a function of time for a variety of PTAs; we consider the current International PTA, and speculate into the era of the Square Kilometre Array. The main properties of the first detectable individual SBHBs are also investigated. Contrary to previous work, we cast our results in terms of the detection probability (DP), since the commonly adopted criterion based on a signal-to-noise ratio threshold is statistic-dependent and may result in misleading conclusions for the statistics adopted here. Our results confirm quantitatively that a stochastic signal is more likely to be detected first (with between 75 to 93 per cent probability, depending on the array), but the DP of single-sources is not negligible. Our framework is very flexible and can be easily extended to more realistic arrays and to signal models including environmental coupling and SBHB eccentricity.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/433dd8d97cbf0c45826bd6d643fb09563cb19ba6

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Citations in the corpus

Search for an Isotropic Gravitational-wave Background with the Parkes Pulsar Timing Array (2023, background): “Some of these findings may be resolved by invoking anisotropy in the SMBHB source distribution, as simulations suggest a large variance is possible in the spectrum of a GWB (Rosado et al. 2015).”
Selection bias in dynamically measured supermassive black hole samples: its consequences and the quest for the most fundamental relation (2016, methodology): “…predicting what pulsar timing array searches (e.g., Sesana et al. 2008; Hobbs et al. 2010; Sesana2013; Kramer & Champion 2013; Rosado & Sesana 2014; Rosado et al. 2015) for gravitational radiation will see (Bonnor & Rotenberg 1961; Peres 1962; Bekenstein 1973; Buonanno & Damour 2000; Berti et al.…”
The NANOGrav 15 yr Data Set: Evidence for a Gravitational-wave Background (2023, background): “The GWB—rather than GW signals from individually resolved binary systems—is likely to become the first nHz source accessible to PTA observations (Rosado et al. 2015).”
Searching for isotropic stochastic gravitational-wave background in the international pulsar timing array second data release (2021, unknown): “It is expected that the SGWB from SMBHBs will be the first GW signal to be detected with PTAs [15].”
Massive Black Hole Binary Mergers in Dynamical Galactic Environments (2016, background): “The event rate of nearby, hard MBHB which could be observed as individual ‘continuous wave’ sources is expected to be quite low, and likely the first GW detections from PTA will be of a stochastic GW Background (GWB) of unresolved sources (Rosado et al. 2015).”
European Pulsar Timing Array Limits on Continuous Gravitational Waves from Individual Supermassive Black Hole Binaries (2015, background): “Despite not being robust for detection purposes, as 6 A more detailed study of the expected properties of the first detectable SMBHBs can be found in Rosado et al. (2015). pointed out by Arzoumanian et al. (2014), fixed noise analysis upper limits are consistent within 50% of those obtained by…”