The European Large AreaISOSurvey - VIII. 90-μm final analysis and source counts

Abstract

We present a re-analysis of the European Large Area Infrared Space Observatory (ISO) Survey (ELAIS) 90-µm observations carried out with ISOPHOT, an instrument on board the ISO of the European Space Agency. With more than 12 deg 2 , the ELAIS survey is the largest area covered by ISO in a single programme and is about one order of magnitude deeper than the IRAS 100-µm survey. The data analysis is presented and was mainly performed with the PHOT interactive analysis software but using the pairwise method of Stickel et al. for signal processing from edited raw data to signal per chopper plateau. The ELAIS 90-µm catalogue contains 237 reliable sources with fluxes larger than 70 mJy and is available in the electronic version of this article. Number counts are presented and show an excess above the no-evolution model prediction. This confirms the strong evolution detected at shorter (15 µm) and longer (170 µm) wavelengths in other ISO surveys. The ELAIS counts are in agreement with previous works at 90 µm and in particular with the deeper counts extracted from the Lockman hole observations. Comparison with recent evolutionary models show that the models of Franceschini et al. and Guiderdoni et al. (which includes a heavily extinguished population of galaxies) give the best fit to the data. Deeper observations are nevertheless required to discriminate better between the model predictions in the far-infrared, and are scheduled with the Spitzer Space Telescope, which has already started operating, and will also be performed by ASTRO-F.

Dusty star-forming galaxies at high redshift

“…Figure 12 illustrates both 850-870µm number counts (from Scuba, Laboca, Scuba-2, and ALMA Blain et al, 1999;Scott et al, 2002;Chapman et al, 2002;Cowie et al, 2002;Borys et al, 2003;Webb et al, 2003;Barnard et al, 2004;Coppin et al, 2006;Scott et al, 2006;Knudsen et al, 2008;Beelen et al, 2008;Weiß et al, 2009a;Karim et al, 2013;Casey et al, 2013;Chen et al, 2013a) and 450-500µm (from Scuba, Herschel and Scuba-2 Smail et al, 2002;Oliver et al, 2010;Clements et al, 2010;Béthermin et al, 2012b;Geach et al, 2013;Casey et al, 2013;Chen et al, 2013a). Figure 13 illustrates other infrared and submillimeter number counts in the literature in direct units, from 70µm Béthermin et al, 2010a;Berta et al, 2011), 100µm (Héraudeau et al, 2004;Rodighiero & Franceschini, 2004;Kawara et al, 2004;Berta et al, 2011;Magnelli et al, 2013b), 160µm Kawara et al, 2004;Béthermin et al, 2010a;Berta et al, 2011;Magnelli et al, 2013b), 250µm and 350µm Chen+13 (850) Casey+13 (850 Figure 12: Differential submillimeter number counts at 850µm/870µm (left) and 450-500 µm (right). The 850µm and 870µm number counts come the initial Scuba surveys …”

“…The 70µm data is collated from Spitzer MIPS Béthermin et al, 2010a) and Herschel PACS . At 100µm, data are from the ISOPHOT instrument aboard ISO (Héraudeau et al, 2004;Rodighiero & Franceschini, 2004;Kawara et al, 2004) and Herschel PACS Magnelli et al, 2013b). At 160µm-170µm, data are from Spitzer MIPS Béthermin et al, 2010a), ISO ISOPHOT (Kawara et al, 2004), and Herschel PACS Magnelli et al, 2013b).…”

Dissecting the cosmic infra-red background withHerschel/PEP

“…Shaded areas represent ISO and Spitzer data (Rodighiero & Franceschini 2004;Héraudeau et al 2004;Béthermin et al 2010). Inset: Collection of PACS number counts, including this work (red, limited to relative errors ≤15% for clarity sake), PEP Abell 2218 (grey, Altieri et al 2010) and HerMES-PACS (light-blue, Aussel et al, in prep.).…”

Dusty Infrared Galaxies: Sources of the Cosmic Infrared Background

“…Counts have been obtained down to 95 mJy (Héraudeau et al 2004) resolving less than 5% of the CIB as derived from DIRBE by Renault et al (2001).…”