The effect of metallicity on the detection prospects for gravitational waves
Apr, 2010
3 pages
Published in:
- Astrophys.J.Lett. 715 (2010) L138
e-Print:
- 1004.0386 [astro-ph.HE]
Report number:
- LA-UR-10-01970
View in:
Citations per year
Abstract: (arXiv)
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.Note:
- 4 pages of text, 2 figures, 2 tables (ApJ Letters, accepted)
- binaries: close
- stars: evolution
- neutron
- gravitation
- gravitational radiation
- black hole: binary
- neutron star: binary
- metal: solar
- statistics
- sensitivity
References(33)
Figures(2)