Fred Walter
State University of New York at Stony Brook
 

"All the Low Mass Objects - Where do they all come from?"
 

I shall report on a deep multiwavelength survey of the Orion OB1b association in a search for substellar mass objects. Orion OB1 is the largest nearby fossil star formation region.  We have surveyed most of the belt of Orion using CPAPIR on the SMARTS/CTIO 1.5m telescope to about 1 mag deeper than the 2MASS survey. We have complemented this with Bok 90-prime imaging over most of the Orion OB1 association, and KPNO 4m MOSIAC and NEWFIRM imaging in selected regions. When done, we expect to be complete in VRIJHK to about 0.01 solar masses (10 Jovian masses).  The mass function, and the spatial variation therof, will provide important clues to the origin of the very lowest mass free-floating objects in our Galaxy.