Surface Density of Extremely Red Objects with R-J≥5 [chapter]

Angela Hempel, Tom M. Herbst, Dave Thompson
Multiwavelength Mapping of Galaxy Formation and Evolution  
We present the results of a wide-field survey for extremely red objects (EROs), based on J and R band imaging. The survey covers 2.89 deg 2 , consisting of 50 single fields, each approximately 210 arcmin 2 in size. This survey provides a sample of 60 extended objects with a colour of R − J ≥ 5 and J band magnitudes more than 10σ above background (18 mag ≤ J ≤ 20 mag ). Thirty five of these objects have been detected in both J and R-band. We derive a surface density for such EROs of 5.7 ± 0.1 ×
more » ... 0 −3 arcmin −2 , which is about seven times lower than for galaxies with R − K ≥ 6. Stellar population models suggest that these EROs are massive galaxies with an old stellar population in a redshift range of 1.4 ≤ z ≤ 3.0. For this scenario, we estimate the co-moving volume density to be (9.57 ± 1.24) × 10 −6 Mpc −3 .
doi:10.1007/10995020_76 fatcat:5nkugzzmvjetxfwhmb5pp233my