Strong lensing time delay measurement is a promising method to address the Hubble tension,offering a completely independent approach compared with both the cosmic microwave background analysis and the local distance l...Strong lensing time delay measurement is a promising method to address the Hubble tension,offering a completely independent approach compared with both the cosmic microwave background analysis and the local distance ladder.As a third-party examination of the Hubble tension,this method provides a unique perspective.Strongly lensed quasar(gl QSO)systems have demonstrated significant potential in tackling this issue,achieving an impressive 2%accuracy level.However,advancing to 1%or sub-percent accuracy is challenging due to several intrinsic limitations of gl QSOs.Fortunately,strongly lensed supernovae(gl SNe)offer a more robust solution,thanks to their characteristic light curve,significant brightness variations,and additional advantages.The Muztagh-Ata 1.93 m Synergy Telescope(MOST)is an exceptional instrument for monitoring strong lensing time delays.In this study,we simulate the follow-up multi-band light curve monitoring for gl SNe Ia systems,which are expected to be firstly discovered by the Chinese Survey Space Telescope(CSST).The simulation employs the W7 model,integrating strong lensing and microlensing effects.Our results show that with 300 s×9 exposures in each epoch,2 quadruple-image systems and14 double-image systems are observable by MOST each year.MOST can achieve a signal-to-noise ratio(SNR)of approximately 50 for the brightest images of gl SNe Ia,while even the faintest images maintain an SNR of at least 7.Using a standard SNe Ia light curve template for fitting,we measured the time delays.With a 2-d cadence,MOST achieves a relative time delay error of less than 4.9%,with the bias typically remaining below 0.57%.Finally,we performed a Hubble parameter estimation.For a typical gl SNe Ia system,the H0error is about±1.8 km s^(-1)Mpc^(-1).This result is comparable or even better than those from LSST.This study highlights the capability of MOST to significantly advance the precision of time delay measurements,offering a promising path toward resolving the Hubble tension.展开更多
A simplified version of generalized Chaplygin gas （GCG） as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae （She Ia） data, 30 high redshift She Ia data, the baryonic acoustic osci...A simplified version of generalized Chaplygin gas （GCG） as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae （She Ia） data, 30 high redshift She Ia data, the baryonic acoustic oscillation peak from SDSS and the CMB data from WMAP3, a strong constraint on this simplified GCG model is obtained. At the 95.4% confidence level we obtain 0.21 ≤ Ωm ≤ 0.31 and 0.994 〈 α 〈 1.0 with the best fit Ωm = 0.25 and a = 1. This best fit scenario corresponds to an accelerating universe with qo ≈-0.65 and z ≈ 0.81 （a redshiR of cosmic phase transition from deceleration to acceleration）.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12333001,61234003,61434004,and 61504141)the CAS Interdisciplinary Project(Grant No.KJZD-EW-L11-04)+1 种基金support from the China Postdoctoral Science Foundation(Grant No.GZC20232990)the National Natural Science Foundation of China(Grant No.12403104)。
文摘Strong lensing time delay measurement is a promising method to address the Hubble tension,offering a completely independent approach compared with both the cosmic microwave background analysis and the local distance ladder.As a third-party examination of the Hubble tension,this method provides a unique perspective.Strongly lensed quasar(gl QSO)systems have demonstrated significant potential in tackling this issue,achieving an impressive 2%accuracy level.However,advancing to 1%or sub-percent accuracy is challenging due to several intrinsic limitations of gl QSOs.Fortunately,strongly lensed supernovae(gl SNe)offer a more robust solution,thanks to their characteristic light curve,significant brightness variations,and additional advantages.The Muztagh-Ata 1.93 m Synergy Telescope(MOST)is an exceptional instrument for monitoring strong lensing time delays.In this study,we simulate the follow-up multi-band light curve monitoring for gl SNe Ia systems,which are expected to be firstly discovered by the Chinese Survey Space Telescope(CSST).The simulation employs the W7 model,integrating strong lensing and microlensing effects.Our results show that with 300 s×9 exposures in each epoch,2 quadruple-image systems and14 double-image systems are observable by MOST each year.MOST can achieve a signal-to-noise ratio(SNR)of approximately 50 for the brightest images of gl SNe Ia,while even the faintest images maintain an SNR of at least 7.Using a standard SNe Ia light curve template for fitting,we measured the time delays.With a 2-d cadence,MOST achieves a relative time delay error of less than 4.9%,with the bias typically remaining below 0.57%.Finally,we performed a Hubble parameter estimation.For a typical gl SNe Ia system,the H0error is about±1.8 km s^(-1)Mpc^(-1).This result is comparable or even better than those from LSST.This study highlights the capability of MOST to significantly advance the precision of time delay measurements,offering a promising path toward resolving the Hubble tension.
文摘A simplified version of generalized Chaplygin gas （GCG） as a dark energy model is studied. By using the latest 162 ESSENCE type Ia supernovae （She Ia） data, 30 high redshift She Ia data, the baryonic acoustic oscillation peak from SDSS and the CMB data from WMAP3, a strong constraint on this simplified GCG model is obtained. At the 95.4% confidence level we obtain 0.21 ≤ Ωm ≤ 0.31 and 0.994 〈 α 〈 1.0 with the best fit Ωm = 0.25 and a = 1. This best fit scenario corresponds to an accelerating universe with qo ≈-0.65 and z ≈ 0.81 （a redshiR of cosmic phase transition from deceleration to acceleration）.
