The Spitzer-IRAC/MIPS Extragalactic survey (SIMES) in the South Ecliptic Pole field

TL;DR

The SIMES survey provides extensive infrared data over a large, low-cirrus extragalactic field, enabling improved statistical studies, galaxy cluster identification at high redshift, and comprehensive multiwavelength analysis.

Contribution

This paper presents the reduction, photometry, and catalog of the SIMES survey, along with methods for galaxy cluster identification and initial scientific results.

Findings

Detected 341,000 sources at 3.6 μm with high completeness.

Identified 27 galaxy clusters at z > 1.3 using IRAC color indices.

Provided a publicly available multiwavelength catalog for the field.

Abstract

We present the Spitzer-IRAC/MIPS Extragalactic survey (SIMES) in the South Ecliptic Pole (SEP) field. The large area covered (7.7 deg$^2$), together with one of the lowest Galactic cirrus emissions in the entire sky and a very extensive coverage by Spitzer, Herschel, Akari, and GALEX, make the SIMES field ideal for extragalactic studies. The elongated geometry of the SIMES area ($\approx$4:1), allowing for a significant cosmic variance reduction, further improves the quality of statistical studies in this field. Here we present the reduction and photometric measurements of the Spitzer/IRAC data. The survey reaches a depth of 1.93 and 1.75 $\mu$Jy (1$\sigma$) at 3.6 and 4.5 $\mu$m, respectively. We discuss the multiwavelength IRAC--based catalog, completed with optical, mid-- and far--IR observations. We detect 341,000 sources with F$_{3.6\mu m} \geq 3\sigma$. Of these, 10% have an associated 24 $\mu$m counterpart, while 2.7% have an associated SPIRE source. We release the catalog through the NASA/IPAC Infrared Science Archive (IRSA). Two scientific applications of these IRAC data are presented in this paper: first we compute integral number counts at 3.6 $\mu$m. Second, we use the [3.6]--[4.5] color index to identify galaxy clusters at z$>$1.3. We select 27 clusters in the full area, a result consistent with previous studies at similar depth.