Imprints of relic gravitational waves on pulsar timing  

作　　者：Ming-Lei Tong Yong-Heng Ding Cheng-Shi Zhao Feng Gao Bao-Rong Yan Ting-Gao Yang Yu-Ping Gao 

机构地区：[1]National Time Service Center,Chinese Academy of Sciences,Xi'an 710600,China [2]Key Laboratory of Time and Frequency Primary Standards,Chinese Academy of Sciences,Xi'an 710600,China [3]Key Laboratory for Research in Galaxies and Cosmology,Chinese Academy of Sciences,Hefei 230026,China [4]University of Chinese Academy of Sciences,Beijing 100049,China [5]Key Laboratory of Precision Navigation and Timing Technology,Chinese Academy of Sciences,Xi'an 710600,China

出　　处：《Research in Astronomy and Astrophysics》2016年第3期111-120,共10页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11103024,11373028 and 11403030);the Science and Technology Research Development Program of Shaanxi Province;the CAS“Light of West China”Program;the Open Project of Key Laboratory for Research in Galaxies and Cosmology,Chinese Academy of Sciences(Grant No.14010205)

摘　　要：Relic gravitational waves （RGWs）, a background originating during inflation, would leave imprints on pulsar timing residuals. This makes RGWs an important source for detection of RGWs using the method of pulsar timing. In this paper, we discuss the effects of RGWs on single pulsar timing, and quantitatively analyze the timing residuals caused by RGWs with different model parameters. In principle, if the RGWs are strong enough today, they can be detected by timing a single millisecond pulsar with high precision after the intrinsic red noises in pulsar timing residuals are understood, even though simultaneously observing multiple millisecond pulsars is a more powerful technique for extracting gravitational wave signals. We correct the normalization of RGWs using observations of the cosmic microwave background （CMB）, which leads to the amplitudes of RGWs being reduced by two orders of magnitude or so compared to our previous works. We obtained new constraints on RGWs using recent observations from the Parkes Pulsar Timing Array, employing the tensor-to-scalar ratio r = 0.2 due to the tensor-type polarization observations of CMB by BICEP2 as a reference value, even though its reliability has been brought into question. Moreover, the constraints on RGWs from CMB and Big Bang nucleosynthesis will also be discussed for comparison.Relic gravitational waves （RGWs）, a background originating during inflation, would leave imprints on pulsar timing residuals. This makes RGWs an important source for detection of RGWs using the method of pulsar timing. In this paper, we discuss the effects of RGWs on single pulsar timing, and quantitatively analyze the timing residuals caused by RGWs with different model parameters. In principle, if the RGWs are strong enough today, they can be detected by timing a single millisecond pulsar with high precision after the intrinsic red noises in pulsar timing residuals are understood, even though simultaneously observing multiple millisecond pulsars is a more powerful technique for extracting gravitational wave signals. We correct the normalization of RGWs using observations of the cosmic microwave background （CMB）, which leads to the amplitudes of RGWs being reduced by two orders of magnitude or so compared to our previous works. We obtained new constraints on RGWs using recent observations from the Parkes Pulsar Timing Array, employing the tensor-to-scalar ratio r = 0.2 due to the tensor-type polarization observations of CMB by BICEP2 as a reference value, even though its reliability has been brought into question. Moreover, the constraints on RGWs from CMB and Big Bang nucleosynthesis will also be discussed for comparison.

关 键 词：gravitational waves： general -- pulsars： general -- inflation 

分 类 号：P145.6[天文地球—天体物理] O412.1[天文地球—天文学]