Here you see side by side a size-adjusted version of our M84 object image and David Malin's deep exposure, both showing about the same region of the Virgo cluster's central region around the bright lenticular (S0) galaxies M84 (round and at right) and M86. The deep image reveals the real extension of the faint outskirts of these galaxies, which is really much larger than the galaxies' conventional images. The scale is even significantly smaller (about 2/3) in the right image.
This fact may have some significance on considerations and estimates concerning the masses of the galaxies: A considerable portion of the galaxies' mass may be in the faint outskirts which are not bright enough for showing up in conventional images. The present author suspects that this may be relevant in the discussion of missing mass, or "dark matter", galaxy and galaxy cluster dynamics, as well as in cosmology.
The deep image in this page is copyrighted by the Australian Astronomical Observatory; see their usage policy.
For technical info on deep astrophotography, look at David Malin's webpage on special photographic techniques.
Last Modification: April 26, 1998