Motivated by the determination of black hole masses with gravitational-wave observations,we calculate the evolution of massive stars through presupernova stages and obtain the mass distribution of black holes.In the f...Motivated by the determination of black hole masses with gravitational-wave observations,we calculate the evolution of massive stars through presupernova stages and obtain the mass distribution of black holes.In the first part,we calculate the evolution of He stars with masses of 30-120 M_(⊙).We study in detail how convective carbon shell burning controls pair-instability pulsations before and during oxygen burning and determine their final fates.In the second part,we calculate the evolution of H-rich stars with initial masses of 13-80 M_(⊙) until Fe core collapse and obtain the possible black hole mass range by applying the criterion of the compactness parameters.From these models,we predict the mass distribution of black holes for stars that undergo Fe core collapse and pair-instability pulsation.The predicted masses for black holes range from 4.2 to 46 M_(⊙),which are consistent with the gravitational-wave observations.展开更多
I estimate the frequencies of gravitational waves from jittering jets that explode core collapse supernovae(CCSNe)to crudely be 5–30 Hz,and with strains that might allow detection of Galactic CCSNe.The jittering jets...I estimate the frequencies of gravitational waves from jittering jets that explode core collapse supernovae(CCSNe)to crudely be 5–30 Hz,and with strains that might allow detection of Galactic CCSNe.The jittering jets explosion mechanism(JJEM)asserts that most CCSNe are exploded by jittering jets that the newly born neutron star(NS)launches within a few seconds.According to the JJEM,instabilities in the accreted gas lead to the formation of intermittent accretion disks that launch the jittering jets.Earlier studies that did not include jets calculated the gravitational frequencies that instabilities around the NS emit to have a peak in the crude frequency range of 100–2000Hz.Based on a recent study,I take the source of the gravitational waves of jittering jets to be the turbulent bubbles(cocoons)that the jets inflate as they interact with the outer layers of the core of the star at thousands of kilometers from the NS.The lower frequencies and larger strains than those of gravitational waves from instabilities in CCSNe allow future,and maybe present,detectors to identify the gravitational wave signals of jittering jets.Detection of gravitational waves from local CCSNe might distinguish between the neutrino-driven explosion mechanism and the JJEM.展开更多
Theories of modified gravity suggest that the propagation speed of gravitational waves(GW)v_gmay deviate from the speed of light c.A constraint can be placed on the difference between c and v_gwith a simple method tha...Theories of modified gravity suggest that the propagation speed of gravitational waves(GW)v_gmay deviate from the speed of light c.A constraint can be placed on the difference between c and v_gwith a simple method that uses the arrival time delay between GW and electromagnetic wave simultaneously emitted from a burst event.We simulated the joint observation of GW and short gamma-ray burst signals from binary neutron star merger events in different observation campaigns,involving advanced LIGO(aLIGO)in design sensitivity and Einstein Telescope(ET)joint-detected with Fermi/GBM.As a result,the relative precision of constraint on v_gcan reach~10~(-17)(aLIGO)and~10^(-18)(ET),which are one and two orders of magnitude better than that from GW170817,respectively.We continue to obtain the bound of graviton mass m_g≤7.1(3.2)×10~(-20)eV with aLIGO(ET).Applying the Standard-Model Extension test framework,the constraint on v_gallows us to study the Lorentz violation in the nondispersive,nonbirefringent limit of the gravitational sector.We obtain the constraints of the dimensionless isotropic coefficients S_(00)^(4)at mass dimension d=4,which are-1×10^(-15)<S_(00)^(4)<9×10^(-17)for aLIGO and-4×10^(-16)<s_(00)^(4<8<10^(-18))for ET.展开更多
Large ground-based laser beam interferometers are presently in operation both in the USA （LIGO） and in Europe （VIRGO） and potential sources that might be detected by these instruments are revisited. The present ge...Large ground-based laser beam interferometers are presently in operation both in the USA （LIGO） and in Europe （VIRGO） and potential sources that might be detected by these instruments are revisited. The present generation of detectors does not have a sensitivity high enough to probe a significant volume of the universe and, consequently, predicted event rates are very low. The planned advanced generation of interferometers will probably be able to detect, for the first time, a gravitational sig- nal. Advanced LIGO and EGO instruments are expected to detect few （some）： binary coalescences consisting of either two neutron stars, two black holes or a neutron star and a black hole. In space, the sensitivity of the planned LISA spacecraft constellation will allow the detection of the gravitational signals, even within a ＂pessimistic＂ range of possible signals, produced during the capture of compact objects by supermassive black holes, at a rate of a few tens per year.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos.11988101 and 11890694the National Key R&D Program of China No.2019YFA0405502+1 种基金supported by the World Premier International Research Center Initiative(WPI),MEXT,Japanthe Japan Society for the Promotion of Science(JSPS)KAKENHI grants JP17K05382,JP20K04024 and JP21H04499。
文摘Motivated by the determination of black hole masses with gravitational-wave observations,we calculate the evolution of massive stars through presupernova stages and obtain the mass distribution of black holes.In the first part,we calculate the evolution of He stars with masses of 30-120 M_(⊙).We study in detail how convective carbon shell burning controls pair-instability pulsations before and during oxygen burning and determine their final fates.In the second part,we calculate the evolution of H-rich stars with initial masses of 13-80 M_(⊙) until Fe core collapse and obtain the possible black hole mass range by applying the criterion of the compactness parameters.From these models,we predict the mass distribution of black holes for stars that undergo Fe core collapse and pair-instability pulsation.The predicted masses for black holes range from 4.2 to 46 M_(⊙),which are consistent with the gravitational-wave observations.
基金supported by a grant from the Israel Science Foundation(769/20)。
文摘I estimate the frequencies of gravitational waves from jittering jets that explode core collapse supernovae(CCSNe)to crudely be 5–30 Hz,and with strains that might allow detection of Galactic CCSNe.The jittering jets explosion mechanism(JJEM)asserts that most CCSNe are exploded by jittering jets that the newly born neutron star(NS)launches within a few seconds.According to the JJEM,instabilities in the accreted gas lead to the formation of intermittent accretion disks that launch the jittering jets.Earlier studies that did not include jets calculated the gravitational frequencies that instabilities around the NS emit to have a peak in the crude frequency range of 100–2000Hz.Based on a recent study,I take the source of the gravitational waves of jittering jets to be the turbulent bubbles(cocoons)that the jets inflate as they interact with the outer layers of the core of the star at thousands of kilometers from the NS.The lower frequencies and larger strains than those of gravitational waves from instabilities in CCSNe allow future,and maybe present,detectors to identify the gravitational wave signals of jittering jets.Detection of gravitational waves from local CCSNe might distinguish between the neutrino-driven explosion mechanism and the JJEM.
基金supported by the National Natural Science Foundation of China under grant 12065017Jiangxi Provincial Natural Science Foundation under grant 20224ACB211001support from the Chinese Academy of Sciences(grant Nos.E329A3M1,E32983U8,and E3545KU2)。
文摘Theories of modified gravity suggest that the propagation speed of gravitational waves(GW)v_gmay deviate from the speed of light c.A constraint can be placed on the difference between c and v_gwith a simple method that uses the arrival time delay between GW and electromagnetic wave simultaneously emitted from a burst event.We simulated the joint observation of GW and short gamma-ray burst signals from binary neutron star merger events in different observation campaigns,involving advanced LIGO(aLIGO)in design sensitivity and Einstein Telescope(ET)joint-detected with Fermi/GBM.As a result,the relative precision of constraint on v_gcan reach~10~(-17)(aLIGO)and~10^(-18)(ET),which are one and two orders of magnitude better than that from GW170817,respectively.We continue to obtain the bound of graviton mass m_g≤7.1(3.2)×10~(-20)eV with aLIGO(ET).Applying the Standard-Model Extension test framework,the constraint on v_gallows us to study the Lorentz violation in the nondispersive,nonbirefringent limit of the gravitational sector.We obtain the constraints of the dimensionless isotropic coefficients S_(00)^(4)at mass dimension d=4,which are-1×10^(-15)<S_(00)^(4)<9×10^(-17)for aLIGO and-4×10^(-16)<s_(00)^(4<8<10^(-18))for ET.
文摘Large ground-based laser beam interferometers are presently in operation both in the USA （LIGO） and in Europe （VIRGO） and potential sources that might be detected by these instruments are revisited. The present generation of detectors does not have a sensitivity high enough to probe a significant volume of the universe and, consequently, predicted event rates are very low. The planned advanced generation of interferometers will probably be able to detect, for the first time, a gravitational sig- nal. Advanced LIGO and EGO instruments are expected to detect few （some）： binary coalescences consisting of either two neutron stars, two black holes or a neutron star and a black hole. In space, the sensitivity of the planned LISA spacecraft constellation will allow the detection of the gravitational signals, even within a ＂pessimistic＂ range of possible signals, produced during the capture of compact objects by supermassive black holes, at a rate of a few tens per year.
