GOODS-$Herschel$: identification of the individual galaxies responsible for the 80-290$\mu$m cosmic infrared background
| Autor: | Leiton, R., Elbaz, D., Okumura, K., Hwang, H. S., Magdis, G., Magnelli, B., Valtchanov, I., Dickinson, M., Béthermin, M., Schreiber, C., Charmandaris, V., Dole, H., Juneau, S., Borgne, D. Le, Pannella, M., Pope, A., Popesso, P. |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | A&A 579, A93 (2015) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1051/0004-6361/201424931 |
| Popis: | We propose a new method of pushing $Herschel$ to its faintest detection limits using universal trends in the redshift evolution of the far infrared over 24$\mu$m colours in the well-sampled GOODS-North field. An extension to other fields with less multi-wavelength information is presented. This method is applied here to raise the contribution of individually detected $Herschel$ sources to the cosmic infrared background (CIRB) by a factor 5 close to its peak at 250$\mu$m and more than 3 in the 350$\mu$m and 500$\mu$m bands. We produce realistic mock $Herschel$ images of the deep PACS and SPIRE images of the GOODS-North field from the GOODS-$Herschel$ Key Program and use them to quantify the confusion noise at the position of individual sources, i.e., estimate a "local confusion noise". Two methods are used to identify sources with reliable photometric accuracy extracted using 24$\mu$m prior positions. The clean index (CI), previously defined but validated here with simulations, which measures the presence of bright 24$\mu$m neighbours and the photometric accuracy index (PAI) directly extracted from the mock $Herschel$ images. After correction for completeness, thanks to our mock $Herschel$ images, individually detected sources make up as much as 54% and 60% of the CIRB in the PACS bands down to 1.1 mJy at 100$\mu$m and 2.2 mJy at 160$\mu$m and 55, 33, and 13% of the CIRB in the SPIRE bands down to 2.5, 5, and 9 mJy at 250$\mu$m, 350$\mu$m, and 500$\mu$m, respectively. The latter depths improve the detection limits of $Herschel$ by factors of 5 at 250$\mu$m, and 3 at 350$\mu$m and 500$\mu$m as compared to the standard confusion limit. Interestingly, the dominant contributors to the CIRB in all $Herschel$ bands appear to be distant siblings of the Milky Way ($z$$\sim$0.96 for $\lambda$$<$300$\mu$m) with a stellar mass of $M_{\star}$$\sim$9$\times$10$^{10}$M$_{\odot}$. Comment: 22 pages, 16 figures. Accepted for publication by Astronomy and Astrophysics |
| Databáze: | arXiv |
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