Interferometric Detections of GOODS 850-5 at 1 mm and 1.4 GHz

Abstract

We have obtained a position (at subarcsecond accuracy) of the submillimeter bright source GOODS 850-5 (also known as GN 10) in the GOODS-North field using the IRAM Plateau de Bure interferometer at 1.25 mm wavelengths (MM J123633+6214.1; flux density: S_{1.25 mm} = 5.0 +/- 1.0 mJy). This source has no optical counterpart in deep ACS imaging down to a limiting magnitude of i₇₇₅ = 28.4 mag and its position is coincident with the position found in recent submillimeter mapping obtained at the SMA. Using deep VLA imaging at 20 cm, we find a radio source (S_{20 cm} = 34.4 +/- 4.2 μJy) at the same position that is significantly brighter than reported by Wang and coworkers (but in agreement with a 3 σ detection previously reported by Pope and coworkers). The source is detected by Spitzer in IRAC as well as at 24 μm. We apply different photometric redshift estimators using measurements of the dusty, mid/far-infrared part of the SED and derive a redshift z ~ 4. Given our detection in the millimeter and radio we consider a significantly higher redshift (e.g., z ~ 6 recently proposed by Wang and coworkers) unlikely. MM J123633+6214.1 alias GOODS 850-5 nevertheless constitutes a bright representative of the high-redshift tail of the submillimeter galaxy population that may contribute a significant fraction to the (sub)millimeter background.

Based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.