NED Abstract 
Copyright by American Astronomical Society.
Reproduced by permission

2009ApJ...694..222C

Extragalactic Point Source Search in Five-Year WMAP 41, 61, and 94 Ghz Maps

Chen, X.; Wright, E. L.

Abstract. We present the results of an extragalactic point source search
using the five-year Wilkinson Microwave Anisotropy Probe (WMAP) 41, 61, and
94 GHz (Q, V, and W bands) temperature maps. This work is an extension of
our designing and applying a cosmic microwave background (CMB)-free
technique to extract point sources in the WMAP maps. Specifically, we have
formed an internal linear combination map of the three-band maps, with the
weights chosen to remove the CMB anisotropy signal as well as to favor the
selection of flat-spectrum sources. We have also constructed a filter to
recover the true point source flux distribution on the sky. A total of 381
sources are found in our study at the >5{sigma} level outside the WMAP point
source detection mask, among which 89 are "new" (i.e., not present in the
WMAP catalogs). Source fluxes have been calculated and corrected for the
Eddington bias. We have solidly identified 367 (96.3%) of our sources, the
1{sigma} positional uncertainty of which is 2'. The 14 unidentified sources
could be either extended radio structure or obscured by Galactic emission.
We have also applied the same detection approach to simulated maps, which
yielded 364 +/- 21 detections on average. The recovered source distribution
N(>S) agrees well with the simulation input, which proves the reliability
of this method. 

Key words: catalogs, cosmic microwave background, cosmology: observations,
methods: data analysis