The Brera Multiscale Wavelet Detection Algorithm Applied to the Chandra Deep Field–South: Deeper and Deeper

Chandra Deep Fields represent the deepest look at the X-ray sky. We analyzed the Chandra Deep Field-South (CDF-S) with the aid of a dedicated wavelet-based algorithm. Here we present a detailed description of the procedures used to analyze this field, tested and verified by means of extensive simulations. We show that we can safely reconstruct the log N - log S source distribution of the CDF-S down to limiting fluxes of 2.4 × 10 -17 and 2.1 × 10 -16 ergs s -1 cm -2 in the soft (0.5-2 keV) and hard (2-10 keV) bands, respectively, fainter by a factor of ≳2 than current estimates. At these levels we can account for ≳90% of the 1-2 keV and 2-10 keV X-ray background.