DEEP Drilling into the Kuiper Belt: First Results from the DECam Ecliptic Exploration Project

Monday, 05 February 2024 noon — 1 p.m. MST

AURA Lecture Hall

NOIRLab South Colloquia
David Gerdes (University of Michigan)

The DECam Ecliptic Exploration Project (DEEP)  is a three year NOAO/NOIRLab Survey that was allocated 46.5 nights to discover and measure the properties of thousands of trans-Neptunian objects (TNOs) to magnitudes as faint as VR~27, corresponding to sizes as small as 20 km diameter. To reach this sensitivity, we employ the "shift-and-stack" technique, in which groups of  ~100 images are combined at a range of motion vectors to detect TNOs that are much fainter than the single exposure depth of VR~23 mag. Through this approach, we reach a depth that is approximately 2.5 magnitudes fainter than the standard LSST "wide fast deep" nominal survey depth of 24.5 mag. DEEP's unprecedented combination of survey area and depth enables quantitative leaps forward in our understanding of the Kuiper Belt populations. In this talk I'll give an overview of the DEEP survey design and analysis strategy. I will then describe how we searched twenty 3 sq. deg. DECam fields and detected approximately 2300 candidate sources with KBO-like motion at S/N >6.5. We have used a subset of these objects to compute the absolute magnitude (H) distribution of the Cold Classical Kuiper Belt, and find consistency with both an exponentially tapered power-law, which is predicted by streaming instability models of planetesimal formation.