A new study on Expansion of the Universe by Gravitational Lensing

 

A very interesting article has been published in Science magazine today with the title and the abstract below about the unknown source of acceleration of the Universe:

Cosmological Constraints from Strong Gravitational Lensing in Clusters of Galaxies

Eric Jullo,^1,2 Priyamvada Natarajan,^3,4,* Jean-Paul Kneib,² Anson D’Aloisio,⁴ Marceau Limousin,^2,5 Johan Richard,⁶ Carlo Schimd²

Current efforts in observational cosmology are focused on characterizing the mass-energy content of the universe. We present results from a geometric test based on strong lensing in galaxy clusters. Based on Hubble Space Telescope images and extensive ground-based spectroscopic follow-up of the massive galaxy cluster Abell 1689, we used a parametric model to simultaneously constrain the cluster mass distribution and dark energy equation of state. Combining our cosmological constraints with those from x-ray clusters and the Wilkinson Microwave Anisotropy Probe 5-year data gives _m = 0.25 ±0.05 and w_x = –0.97 ±0.07, which are consistent with results from other methods. Inclusion of our method with all other available techniques brings down the current 2 contours on the dark energy equation-of-state parameter w_x by ~30%.

All of the science appeared in this paper, has been extracted from Hubble space telescope image of Galaxy cluster Abel 1689, below:

pic: galxy cluster 1689, HST 

The story is that using the gravitational lensing effect /which is a phenomena anticipated in the theory of General relativity/ give us the ability to measure the energy-matter content of universe, its properties and the geometry of the Universe. The quest, is to find out the cause of unknown source of energy which accelerate our universe expansion, known as Dark Energy.

Gravitational lensing  is based on the fact that the energy and matter in universe can distort the light paths of galaxies/light sources/ we seen in the universe. Cosmologist used this distortion to determine the amount of energy-matter and its properties.

All the science and what happens is really fascinating, but even you do not enjoy the main story, you can be fascinated by the 1689 galaxy cluster image and surprised how it is be able to extract information out of this beauty.

 

Shant  Baghramian