The Research For Gravity Physics Of Binary Neutron Star Merger GW170817

On 2017 August 17 a binary neutron star merger(GW170817)was firstly observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors.GW170817 was very loud and lasted for?100s.GW170817 was detected with a combined signal-to-noise ratio across the three-instrument network of 32.4.The false alarm rate is less than 1.25×10-5yr-1.Independently,a gamma-ray signal,classified as a short gamma-ray burst(SGRB),GRB170817A,coincident in time and sky location with GW170817 was detected using the Fermi Gamma-ray Burst Monitor(GBM)and the International Gamma-Ray Laboratory(INTEGRAL).An optical counterpart(OT),Swope Supernova Survey 2017a(SSS17a,later with the IAU identification of AT 2017gfo),was first discovered by the One-Meter Two Hemisphere(1M2H)team less than 11 hours after merger,associated with NGC 4993.At a luminosity distance of 40-14+8Mpc.More than 70 ground or space observatory telescopes in different bands have observed the event.These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars followed by a short gamma-ray burst(GRB 170817A)and a kilonova/macronova.The results of this campaign mark a new era in multi-messenger,time-domain astronomy.Therefore,the discovery of GW170817 is significant in Fundamental Physics,and provides an excellent opportunity for the researches of testing fundamental physics theory.This dissertation is mainly based on GW170817 and its electromagnetic companions GRB 170817A and AT 2017gfo to carry out the research on the weak equivalence principle(WEP)test.The mainly innovations of the study are as follows:Firstly,the research on the WEP through the observations of high energy astronomical events(HEAE)has mainly focused on the gravitational potential of the Milky Way,while the influence of the host galaxy has been neglected because there are many uncertainties in host galaxies.Fortunately,the source is located in host galaxy NGC 4993.The WEP test is significantly enhanced through the gravitational potential by the joint action of the Milky Way and the NGC 4993.For GW170817/GRB 170817A,the Post-Newton parameter difference ??<10-9,for GW170817/AT 2017gfo,the Post-Newton parameter difference ??<10-4.Our result is tighter by 1 to 2 orders of magnitude than the results of other paper only focus on the Milky Way.Secondly,Combining the observations of LIGO,Fermi,HST and other observation groups on the angle offset and the absorption spectrum of the electromagnetic counterpart to the interstellar medium absorption,we have fully considered the influence of the possible position of the gravitational wave source on the WEP test.The SN2 Natal Kick during the formation of the GW170817 event will have a greater impact on the WEP test,with a maximum deviation of approximately 20%.Thirdly,we analyzed the influence of the halo mass of NGC 4993 with a 0.2 dex scatter in the 2MASS redshift survey(2MRS)on the WEP test.The study found that with the increase of the halo quality,the WEP test is gradually enhanced,and the upper limit of the Post-Newton parameter difference ?? is gradually reduced.The test with the maximum mass of 1012.4/hM(?)is 2 times stronger than the result of the minimum mass of 1012.0/hM(?).