Papers
Topics
Authors
Recent
Gemini 2.5 Flash
Gemini 2.5 Flash
173 tokens/sec
GPT-4o
7 tokens/sec
Gemini 2.5 Pro Pro
46 tokens/sec
o3 Pro
4 tokens/sec
GPT-4.1 Pro
38 tokens/sec
DeepSeek R1 via Azure Pro
28 tokens/sec
2000 character limit reached

Dark matter-rich early-type galaxies in the CASSOWARY 5 strong lensing system (1108.0678v1)

Published 2 Aug 2011 in astro-ph.CO

Abstract: We study the strong gravitational lensing system number 5 identified by the CASSOWARY survey. In this system, a source at redshift 1.069 is lensed into four detected images by two early-type galaxies at redshift 0.388. The observed positions of the multiple images are well reproduced by a model in which the total mass distribution of the deflector is described in terms of two singular isothermal sphere profiles. By modelling the lens galaxy spectral energy distributions, we measure the lens luminous masses and stellar mass-to-light ratios. These values are used to disentangle the luminous and dark matter components in the vicinity of the multiple images. We estimate that the dark over total mass ratio projected within a cylinder centred on the primary lens and with a radius of 12.6 kpc is 0.8 +/- 0.1. We contrast these measurements with the typical values found at similar distances (in units of the effective radius) in isolated lens galaxies and show that the amount of dark matter present in these lens galaxies is almost a factor four larger than in field lens galaxies with comparable luminous masses. Data and models are therefore consistent with interpreting the lens of this system as a galaxy group. We infer that the overdense environment and dark matter concentration in these galaxies must have affected the assembly of the lens luminous mass components. We conclude that further multi-diagnostics analyses on the internal properties of galaxy groups have the potential of providing us a unique insight into the complex baryonic and dark-matter physics interplay that rules the formation of cosmological structures.

Summary

We haven't generated a summary for this paper yet.