Friday Galaxy Blogging : VV114

May 25 2007 Published by under Astronomy & Physics, Pretty Pictures

VV114 is a very interesting galaxy. It's a major merger of at least two big galaxies. If I might go out on a limb, it may even be an advanced merger (on the left) currently strongly interacting with another galaxy (on the right).

The left galaxy is extremely dusty. Sunsets are red because particles in the atmosphere preferentially scatter away the bluer light. Redder light penetrates the dust better. Just before the Sun sets, we're looking at it through as much atmosphere as we ever see it, so it has to go through the most number of particles in the atmosphere. similarly, very dusty galaxies are red in color. In VV114, this is most striking when you compare the optical light to the infrared light. The left galaxy is nearly invisible in blue light, but is the brighter galaxy in the infrared.

The IR images was taken back in the 1990s, and were part of my first published paper in grad school. The optical image was taken a year or two ago with the CTIO 1.0m telescope. Both images are "false color" -- I've enhanced the colors to bring out the contrast, and of course no IR image can be "true" color, as it would just look all black to our eyes! However, longer wavelengths have redder colors, so qualitatively the colors are what you would expect.



2 responses so far

  • ...and VV 114's properties in the ultraviolet are unusual enough to make it one of a small number of local galaxies that appear largely analogous to the Lyman Break Galaxies seen at redshift z~3.

    Definitely a galaxy that deserves more attention.

  • Chris' Wills says:

    I like the galaxy pictures, especially as these haven't been clarified so show what astronomers work with (well I guess you probably work with the raw data, not the pictures, but that will be fuzzy as well)