THE EFFECT OF METALLICITY ON THE DETECTION PROSPECTS FOR GRAVITATIONAL WAVES
THE EFFECT OF METALLICITY ON THE DETECTION PROSPECTS FOR GRAVITATIONAL WAVES
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DOI：
10.1088/2041-8205/715/2/l138
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发表时间：
2010-04
期刊：
影响因子：
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通讯作者：
K. Belczynski;M. Dominik;T. Bulik;R. O’Shaughnessy;Chris L. Fryer;D. Holz
中科院分区：
文献类型：
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作者：
K. Belczynski;M. Dominik;T. Bulik;R. O’Shaughnessy;Chris L. Fryer;D. Holz
来自斯隆数字巡天（约30万个星系）的数据表明，最近的恒星形成（在过去10亿年内）是双峰的：一半的恒星形成于含有大量金属的气体（太阳金属丰度），另一半形成于比氦更重的元素（约10%-30%的太阳元素）。对最亮恒星质量损失的理论研究得出的恒星源黑洞（BH）质量（~ 30-80 M☉）明显高于之前对亚太阳成分的估计。我们结合这些发现来估计探测到由双紧致天体激发的引力波（GWs）的概率。我们的结果表明，低金属丰度的环境显著地促进了至少有一个黑洞的双紧致双星的形成。特别是，我们发现，如果金属丰度从太阳能（如所有先前的估计）减少到50%的太阳能和10%的太阳能金属丰度混合，则GW检测率增加了20倍。目前两台最大的仪器对中子星-中子星（NS-NS）双吸气（VIRGO: ~ 9 Mpc; LIGO: ~ 18）的灵敏度不足以保证首次探测。然而，我们的结果表明，如果未来的仪器将灵敏度提高到~ 50-100 Mpc，预计在观测的第一年就可以检测到GWs。以前认为NS-NS激发是GW检测最可能的来源。我们的研究结果表明，BH-BH双星比NS-NS系统的可能性高25倍，我们正处于GW检测的尖端。
Data from the Sloan Digital Sky Survey (∼300,000 galaxies) indicate that recent star formation (within the last 1 billion years) is bimodal: half of 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 black hole (BH) masses (∼30–80 M☉) 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 neutron star–neutron star (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.