(IMAGE) National Institutes of Natural Sciences Caption Gray data points show the results from previous works by other studies. The colored strip in the left panel is a prediction of their evolution if such massive elliptical galaxies formed 10 to 11 billion years ago (redshift of about 2.3) and evolved without forming new stars to the present universe (redshift of zero). The prediction agrees with the observed trend very well. The middle and left panels clearly show that chemical composition of massive elliptical galaxies does not evolve over cosmic time. Credit ETH Zurich/NAOJ Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.