2018/06/27 by Ayan Mitra, Mitra, Ayan
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Cosmic Phenomena #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Gamma-ray bursts and supernovae #Radio Astronomy Observations and Technology
paper · pdf · doi:10.48550/arxiv.1806.10375
openalex publication_date 2018/06/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The presence of mass inhomogeneities along the line of sight of propagation\nof light fromdistant objects can induce deflection in the flight path of the\nphoton. This phenomenon is called as gravitational lensing. Lensing can have\nboth distortion (shear) and isotropic magnification effects on the source. We\nstudied the effect of lensing magnification on supernova (SN) Ia in this\nthesis. Presence of lensing would introduce a source of contamination to the\nbrightness distribution of the source (SN Ia in our case). Thus it also enables\none to compute the lensing effect indirectly from the Hubble diagram (i.e. from\nthe residual to the Hubble diagram). In this thesis we computed the correlation\nbetween these two effects : the Hubble residual and the computed lensing\nmagnification for the SN by the line of sight foreground dark matter haloes. A\ndetection of positive correlation between these two would signify the\npositivity of lensing signal detection. The data sample is the spectroscopic\nSNe Ia sample from the five years full SNLS data and the Hubble residuals are\nthose of the preliminary cosmology analysis performed on SNLS5 data. We obtain\na signal of \ρ = 0.177 at 2.51 \σ. This result is consistent with the\nprevious SNLS three years data lensing analysis results.\n