Astrophysics (Index)About


(means of identifying distant galaxies)

Dropouts are a means of identifying candidates for distant galaxies through photometry. A dropout is the instance of a source showing in some bands but not others. A high redshift will cause some of the galaxy's typically strong electromagnetic radiation bands (e.g., the high point of its black body spectrum) to be shifted to the degree that the images taken in some bands do not show the galaxy at all. Given a set of bands, a galaxy that shows in bands up to, but not including an R band can be termed a red dropout galaxy. Similarly for a blue dropout galaxy.

Further reading:
BDBD3general for "blue dropout"
RDRD1general for "red dropout"

Referenced by pages:
band shifting
first galaxies
Hubble Ultra-Deep Field (HUDF)
Lyman-break galaxy (LBG)