Star Formation in Nearby Galaxies
What is star formation in nearby galaxies?
The signature of recent star formation in galaxies can be seen in various wavelength bands. most notably the red light of hydrogen-alpha emission arising in HII regions where ionised gas surrounds massive young stars. The ionisation is caused by short wavelength UV emission from the young stars.
These stars are often hidden in dense clouds of gas and dust and may reveal themselves only from the infrared emission from the dust. In more distant galaxies the integrated light from a whole galaxy must be studied to determine its star forming history. However, in nearby galaxies, the spatial distribution of star formation is laid out to see.
Current research
Recent work has combined far UV (FUV) imaging from the Galaxy Evolution Explorer (GALEX) satellite with Hydrogen-alpha images from ground based telescopes to study the star formation history of nearby, face-on, spiral galaxies. A pixel-by-pixel comparison of images in these two bands, compared to models of emission from star forming regions using Starburst99, yields estimates of the age of star formation at every point across the galaxies.
For more information contact John O'Byrne