Surveying the TeV Gamma-Ray Sky with Milagro and HAWC


TeV gamma rays point to Nature's astrophysical accelerators. Many of  
these accelerators output most of their electromagnetic energy in gamma
rays, and their output may flare by more than an order of
magnitude.  In order to study these TeV accelerators, a new type of  
detector was developed with a large field of view and >90% duty
factory.  This detector, called Milagro, used a 5000 square meter pond
of water to detect Cherenkov light from extensive air showers. Milagro
surveyed the 2 pi sr of the Northern Hemisphere and
discovered new sources of TeV gamma rays as well as diffuse emission  
from the plane of the Milky Way galaxy. The High Altitude Water  
Cherenkov (HAWC) observatory is a next-generation version of the   Milagro
observatory that will be built in Mexico at an altitude of 13500' and
will have over 10 times the sensitivity of Milagro.