web stats
Home / Science / Astronomy / Elliptical galaxies

Elliptical galaxies

m86 ellipt2 NGC 1132 m87

Elliptical galaxies

Elliptical galaxies are shaped like a spheriod, or elongated sphere. In the sky, where we can only see two of their three dimensions, these galaxies look like elliptical, or oval, shaped disks. The light is smooth, with the surface brightness decreasing as you go farther out from the center. Elliptical galaxies are given a classification that corresponds to their elongation from a perfect circle, otherwise known as their ellipticity. The larger the number, the more elliptical the galaxy is. So, for example a galaxy of classification of E0 appears to be perfectly circular, while a classification of E7 is very flattened. The elliptical scale varies from E0 to E7. Elliptical galaxies have no particular axis of rotation.

The masses of elliptical galaxies cover a large range: from about 107 up to 1013 solar masses. The corresponding range of diameters is about 1/10 kpc up to about 100 kpc, and the absolute blue magnitude varies over a correspondingly large range from -8 to -23. Thus, the smallest of the elliptical galaxies, which are called dwarf ellipticals, may be only a little larger than globular clusters, while the giant elliptical galaxies like M87 are among the largest galaxies in the Universe. This is a much larger range in size than is seen for the spiral galaxies.
Elliptical galaxies exhibit far less evidence for young stars, gas, or dust than do spiral galaxies, and have larger random motion of stars than in spiral galaxies where the motion is a more ordered rotation.

About Mohammad Daeizadeh

  • تمامی فایل ها قبل از قرار گیری در سایت تست شده اند.لطفا در صورت بروز هرگونه مشکل از طریق نظرات مارا مطلع سازید.
  • پسورد تمامی فایل های موجود در سایت www.parsseh.com می باشد.(تمامی حروف را می بایست کوچک وارد کنید)
  • Password = www.parsseh.com

Leave a Reply

Your email address will not be published. Required fields are marked *

*