Spitzer awards time to observe Euclid Deep Field South


The Spitzer survey of the Euclid Deep Field South will add critical coverage to help identify high-z galaxies and distinguish dusty low-z contaminants.

News Release • March 15, 2019

Prof. Claudia Scarlata (University of Minnesota) has been awarded Spitzer time to observe Euclid Deep Field South. Her team will conduct a 687hr survey of the definitive southern continuous viewing zone deep field of the 2020s using IRAC, the primary instrument on Spitzer. 
Scarlata's team will conduct a 687hr IRAC survey of the definitive southern continuous viewing zone deep field of the 2020s. This field was chosen as the optimal deep field near the south ecliptic pole following a joint analysis by Euclid, LSST, and WFIRST at the end of January 2019. It is the 20 deg2 region closest to the south ecliptic pole, and hence the darkest southern area of the sky, free of bright stars, with low galactic extinction and low stellar density. It is in the continuous viewing zone of WFIRST and JWST. In this field, Euclid will provide high spatial-resolution near-IR imaging (Y, J, and H), spectroscopy (0.92< lambda <1.85 microns), and coverage with monthly cadence from 2022 to 2028. Additionally, the field position and geometry are optimized to maximize the synergy with future surveys.
The primary goal of this survey is to secure legacy data that will allow a broad range of science over the next decade with Spitzer, Euclid, WFIRST, JWST, and ALMA. The data in the 3-5 micron wavelength range are essential to measure stellar masses at z>3 and the addition of this southern field to the existing Spitzer archive will triple the number of extremely rare, massive, sources that will be observable by ALMA. Stellar mass, together with environment, is the most important physical property regulating the evolution of galaxies. Additionally, these new data will enable new science and improve cosmological constraints from the dark energy surveys. Finally, the observing strategy optimizes Spitzer's scheduling flexibility by observing a field near the south ecliptic pole, enabling a minimal impact despite the large time request. Besides Spitzer, no current or planned future missions can conduct deep yet wide area surveys at these wavelengths. 
The target depth of this survey has been selected to be 0.28 and 0.40μJy RMS at ch1/2 respectively. This is well matched in depth to the Euclid and LSST single epoch depths (~1μJy at 0.5-2μm), the depths of the grism observations, as well as archival data over existing LSST deep drilling fields. This enables the broadest range of science given the cost of the observations. The depth also correspond to M* at the end point of reionization (z~6).