Deep Imaging of the Virgo Cluster

Chris Mihos, Paul Harding, John Feldmeier, Heather Morrison

Department of Astronomy, Case Western Reserve University
As the nearest galaxy cluster to us, the Virgo Cluster gives us an up-close look at the evolution of galaxies in clusters. As galaxies collide and interact gravitationally, stars are stripped out of their parent galaxies and strewn throughout the cluster, giving rise to the very faint and diffuse "intracluster light" (ICL).

The goal of our project is to use Case's newly-upgraded Burrell Schmidt wide-field telescope atop Kitt Peak in Arizona to create a very deep image of the Virgo cluster and see if we can actually find stars being stripped from Virgo galaxies to form the ICL.

Below is a composite image consisting of 36 coadded 15-minute images of the Virgo cluster. Click on any of these small images to see a full-size version.


A shallow stretch, showing the bright galaxies.
A deep stretch, showing much fainter features.

Digital filtering let us "average" light over larger areas, enhancing our ability to see faint features. Here are some examples of digital filters applied to the image. Note the very extended, diffuse envelopes of light surrounding the galaxies, and the tendrils of light coming from several galaxies -- we are seeing the formation of the ICL!


(after applying a 10x10 pixel median filter)
(after applying a 100x100 pixel median filter)

(after applying a 10x10 pixel modal filter)