Time Delay Analysis of the Lensed Quasar SDSS J1001+5027

Abstract

We modify the algorithm we proposed before in Aghamousa & Shafieloo (2015) on time delay estimation of the strong lens systems incorporating weighted cross-correlation and weighted summation of correlation coefficients. We show the high performance of this algorithm by applying it on Time Delay Challenge (TDC1) simulated data. We apply then our proposed method on the light curves of the lensed quasar SDSS J1001+5027 since this system has been well studied by other groups to compare our results with their findings. In this work we propose a new estimator namely "mirror" estimator along with a list of criteria for reliability test of estimation. Our mirror estimator results to −117.1 +7.1 −3.7 and −117.1 +7.2 −8.8 using simple Monte Carlo simulations and simulated light curves provided by Rathna Kumar et al. (2013) respectively. Although TDC1 simulations do not reflect the properties of SDSS J1001+5027 light curves, using these simulations results to smaller uncertainty which shows the higher quality observations can lead to substantially more precise time delay estimation. Our time delay estimation is in agreement with findings of the other groups for this strong lens system and the difference in the size of the error bars reflects the importance of appropriate light curve simulations.

Probing the theory of gravity with gravitational lensing of gravitational waves and galaxy surveys

“…where, γ1 and γ2 are the cosmic shears in the Fourier space with k = (k1, k2). From the observables such as the galaxy distributions and its shape, the lensing field can be inferred from the data of the upcoming galaxy surveys (Aghamousa et al 2016;Refregier et al 2010;LSST Science Collaboration et al 2009;Dore et al 2018b,a).…”

“…We estimate the feasibility of measuring the lensing of the gravitational wave signal emitted from astrophysical sources in the frequency band 10 − 1000 Hz and 10 −4 − 10 −1 Hz by cross-correlating with the upcoming large-scale structure surveys such as DESI (Dark Energy Spectroscopic Instrument) Aghamousa et al (2016), EUCLID Refregier et al (2010), LSST (The Large Synoptic Survey Telescope) LSST Science Collaboration et al (2009), SPHEREx Dore et al (2018a), WFIRST (Wide Field Infrared Survey Telescope) (Dore et al 2018b), etc. which also probes the cosmic density field.…”

Time-dependence of the astrophysical stochastic gravitational wave background

“…The time-derivative of the SGWB denoted by T captures the temporal fluctuation in the SGWB signal which is related to the event rate of the GW signal contributing at a particular frequency of the SGWB. The spatial distribution of the astrophysical GW sources are expected to follow the spatial distribution of the galaxies and can be estimated by cross-correlating with the galaxy distribution available from the upcoming cosmological surveys (such as DESI (Aghamousa et al 2016 ). The cross-correlation of the SGWB with the galaxy field can probe the time-dependent bias of the SGWB signal for different cosmological redshifts as we have discussed in Sec.…”

Developing a unified pipeline for large-scale structure data analysis with angular power spectra – II. A case study for magnification bias and radio continuum surveys

“…The forthcoming galaxy surveys will be game-changing probes of the LSS, observing from millions to billions of sources at different wavelengths and exploiting various techniques. A few examples of LSS experiments that will take data in the near future are: the European Space Agency's satellite Euclid (Laureijs et al 2011;Amendola et al 2013Amendola et al , 2018, the Large Synoptic Survey Telescope (LSST Dark Energy Science Collaboration 2012), or the Dark Energy Survey Instrument (Aghamousa et al 2016), in the optican/near-IR band; and the Square Kilometre Array (SKA, Maartens et al 2015;Abdalla et al 2015;Bacon et al 2018) and its precursors, at radio frequencies.…”