Formation of neutron star / black hole binaries and their merger rate in the local Universe

中子星/黑洞双星的形成及其在当地宇宙中的合并率

• 批准号: 231548287
• 负责人: Professor Dr. Thomas Tauris
• 金额: --
• 依托单位: Institut for Fysik og Astronomi
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/231548287?language=en
• 关键词: Formation; neutron; star; black; hole

The expected detection of gravitational waves will open a new window to the Universe and compliment our knowledge of astrophysical sources obtained from photons and neutrinos. The advanced LIGO (Laser Interferometer Gravitational-Wave Observatory) detector, together with its European sister VIRGO and the German detector GEO 600, will be operational in 2014 and reach full sensitivity in 2015. The most promising candidate sources for transient burst detections of high-frequency gravitational waves (10 Hz - 10 kHz) are merging neutron stars (NS) and black holes (BH). These compact objects are formed in tight binaries and undergo spiral-in due to continuous emission of gravitational waves until they finally merge in a violent transient event - possibly leading to a short gamma-ray burst. The main aim of this project is to calculate theoretically the rate of such merging NS/BH in the local Universe using our best up-to-date knowledge of stellar and binary evolution. These results will be compared to the upcoming LIGO detection rates which will enable us to better constrain the input physics behind key binary stellar interactions such as mass and angular momentum loss, common envelopes, evolution of naked helium stars, the role of rapid stellar rotation in massive binaries and, finally, the momentum kick imparted to newborn NS and BH. A second aim of this project is to better understand - and to quantify - the formation, the location, the properties and the lifetimes of Galactic recycled radio pulsars orbiting NS or BH. Whereas we know of 9 radio pulsars orbiting another NS we still have no detections of a radio pulsar orbiting a BH. With this project we hope to gain theoretical knowledge about such systems which will enhance the chance of success in future radio surveys. A recycled pulsar is formed when an old NS is spun up to a high spin frequency via accretion of mass and angular momentum from a companion star in a close binary system. Many aspects of this mass-transfer process and the accretion physics involved are not well understood but play a crucial role for recycling radio pulsars to high spin rates and low B-fields, which make them detectable for billions of years to follow. A third outcome of this study is therefore a better knowledge of the evolution of high-mass X-ray binaries which again can be confronted with observations. To model the population of compact binaries the evolution of a large sample of binary star systems is needed - from the zero age main sequence, via mass transfer and supernova explosions - in order to predict the number of both observable radio pulsars orbiting NS and BH as well as the advanced LIGO detection rate of mergers. To achieve these goals we make use of advanced population synthesis techniques with Monte Carlo simulations and explore new aspects of massive binary stellar evolution for the first time.

引力波的预期探测将为宇宙打开一扇新的窗口，并补充我们从光子和中微子中获得的天体物理学来源的知识。先进的LIGO（激光干涉引力波天文台）探测器及其欧洲姊妹探测器VIRGO和德国探测器GEO 600将于2014年投入运行，并于2015年达到完全灵敏度。最有希望的高频引力波（10 Hz - 10 kHz）瞬态爆发探测的候选源是合并中子星（NS）和黑洞（BH）。这些紧凑的物体形成于紧密的双星系统中，并由于引力波的持续发射而经历螺旋式进入，直到它们最终在剧烈的瞬态事件中合并-可能导致短暂的伽马射线爆发。这个项目的主要目的是利用我们最好的恒星和双星演化的最新知识，从理论上计算这种合并NS/BH在本地宇宙中的速率。这些结果将与即将到来的LIGO检测率进行比较，这将使我们能够更好地约束关键双星相互作用背后的输入物理，例如质量和角动量损失，共同的包络，裸氦星的演化，快速恒星旋转在大质量双星中的作用，最后，赋予新生NS和BH的动量踢。该项目的第二个目的是更好地了解-并量化-银河系回收无线电卫星的形成，位置，属性和寿命，它们绕着NS或BH运行。虽然我们知道有9颗射电脉冲星绕着另一颗NS运行，但我们仍然没有探测到一颗射电脉冲星绕着BH运行。通过这个项目，我们希望获得有关这种系统的理论知识，这将提高未来无线电调查的成功机会。当一个老的NS通过吸积来自一个紧密双星系统中的伴星星星的质量和角动量而旋转到一个高的旋转频率时，就形成了一个再循环脉冲星。这个质量转移过程和所涉及的吸积物理学的许多方面还没有得到很好的理解，但对于将射电望远镜回收到高自旋速率和低B场，这使得它们在随后的数十亿年内都可以被探测到，发挥着至关重要的作用。因此，这项研究的第三个成果是更好地了解高质量X射线双星的演化，这再次可以面对观测。为了模拟致密双星的种群，需要大量的双星星星系统的演化--从零年龄的主序开始，通过质量转移和超新星爆炸--以预测绕NS和BH轨道运行的可观测射电双星的数量以及先进的LIGO合并探测率。为了实现这些目标，我们利用先进的人口合成技术与蒙特卡罗模拟和探索大规模双星演化的新方面的第一次。