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arXiv · 1004.0386

The effect of metallicity on the detection prospects for gravitational waves

K. Belczynski·M. Dominik·T. Bulik·R. O'Shaughnessy·C. L. Fryer·D. E. Holz
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Abstract

Data from the SDSS (300,000 galaxies) indicates that recent star formation (within the last 1 billion years) is bimodal: half the stars form from gas with high amounts of metals (solar metallicity), and the other half form with small contribution of elements heavier than Helium (10-30% solar). Theoretical studies of mass loss from the brightest stars derive significantly higher stellar-origin BH masses (30-80 Msun) than previously estimated for sub-solar compositions. We combine these findings to estimate the probability of detecting gravitational waves (GWs) arising from the inspiral of double compact objects. Our results show that a low metallicity environment significantly boosts the formation of double compact object binaries with at least one BH. In particular, we find the GW detection rate is increased by a factor of 20 if the metallicity is decreased from solar (as in all previous estimates) to a 50-50 mixture of solar and 10% solar metallicity. The current sensitivity of the two largest instruments to NS-NS binary inspirals (VIRGO: 9 Mpc; LIGO: 18) is not high enough to ensure a first detection. However, our results indicate that if a future instrument increased the sensitivity to 50-100 Mpc, a detection of GWs would be expected within the first year of observation. It was previously thought that NS-NS inspirals were the most likely source for GW detection. Our results indicate that BH-BH binaries are 25-times more likely sources than NS-NS systems and that we are on the cusp of GW detection.

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K. Belczynski, M. Dominik, T. Bulik, R. O'Shaughnessy, C. L. Fryer, D. E. Holz. 2010-05-07. The effect of metallicity on the detection prospects for gravitational waves. https://doi.org/10.1088/2041-8205%2F715%2F2%2Fl138

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