Implications Of Hα Observations For Studies Of The CMB

Document Type

Book Chapter

Publication Date


Published In

Microwave Foregrounds

Series Title

Astronomical Society Of The Pacific Conference Series


We summarize the relationship between the free-free emission foreground and Galactic H-alpha emission. H-alpha observations covering nearly the entire celestial sphere are described. These data provide a template to isolate and/or remove the effect of Galactic free-free emission from observations of the cosmic microwave background. Spectroscopy and imaging provide to complementary methods for measuring the H-alpha emission. Spectroscopy is favored for its velocity resolution and imaging is favored for tis angular resolution. With templates of the three dominant foregrounds, namely synchrotron, thermal dust, and free-free emissions, it may be possible to quantify the location and the brightness of another foreground such as that from rotating dust grains.

Published By

Astronomical Society Of The Pacific


A. de Oliveira-Costa And M. Tegmark


Sloan Summit On Origins

Conference Dates

November 14-15, 1998

Conference Location

Princeton, New Jersey