Bibcode
Berta, S.; Magnelli, B.; Lutz, D.; Altieri, B.; Aussel, H.; Andreani, P.; Bauer, O.; Bongiovanni, A.; Cava, A.; Cepa, J.; Cimatti, A.; Daddi, E.; Dominguez, H.; Elbaz, D.; Feuchtgruber, H.; Förster Schreiber, N. M.; Genzel, R.; Gruppioni, C.; Katterloher, R.; Magdis, G.; Maiolino, R.; Nordon, R.; Pérez-García, A. M.; Poglitsch, A.; Popesso, P.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Saintonge, A.; Santini, P.; Sanchez-Portal, M.; Shao, L.; Sturm, E.; Tacconi, L. J.; Valtchanov, I.; Wetzstein, M.; Wieprecht, E.
Bibliographical reference
Astronomy and Astrophysics, Volume 518, id.L30
Advertised on:
7
2010
Journal
Citations
121
Refereed citations
107
Description
The constituents of the cosmic IR background (CIB) are studied at its
peak wavelengths (100 and 160 μm) by exploiting Herschel/PACS
observations of the GOODS-N, Lockman Hole, and COSMOS fields in the PACS
evolutionary probe (PEP) guaranteed-time survey. The GOODS-N data reach
3σ depths of ~3.0 mJy at 100 μm and ~5.7 mJy at 160 μm. At
these levels, source densities are 40 and 18 beams/source, respectively,
thus hitting the confusion limit at 160 μm. Differential number
counts extend from a few mJy up to 100-200 mJy, and are approximated as
a double power law, with the break lying between 5 and 10 mJy. The
available ancillary information allows us to split number counts into
redshift bins. At z ≤ 0.5 we isolate a class of luminous sources
(LIR ~ 1011 L_&sun;), whose SEDs resemble
late-spiral galaxies, peaking at ~130 μm restframe and significantly
colder than what is expected on the basis of pre-Herschel models. By
integrating number counts over the whole covered flux range, we obtain a
surface brightness of 6.36±1.67 and 6.58±1.62 [ nW
m-2 sr-1] at 100 and 160 μm, resolving ~45% and
~52% of the CIB, respectively. When stacking 24 μm sources, the
inferred CIB lies within 1.1σ and 0.5σ from direct
measurements in the two bands, and fractions increase to 50% and 75%.
Most of this resolved CIB fraction was radiated at z ≤ 1.0, with 160
μm sources found at higher redshift than 100 μm ones.
Herschel is an ESA space observatory with science instruments provided
by European-led Principal Investigator consortia and with important
participation from NASA.Table 1 and Appendix A are only available in
electronic form at http://www.aanda.org