Monday, October 23rd, at Institut d'Astrophysique Spatiale, room 1
The jury is composed of:
Guillaume Pineau des Forêts, president
Chas Beichman, referee
François Hammer, referee
Jean-Loup Puget, supervisor
How to come to IAS ?
This thesis deals with the analysis of the FIRBACK deep survey
performed in the far infrared at l = 170 µ m with the Infrared Space Observatory, whose aim is the study of the galaxies contributing to the Cosmic Infrared Background, and with the modellisation of galaxy evolution in the mid-infrared to submillimeter range.
The FIRBACK survey covers 3.89° 2 in 3 high galactic latitude and low foreground emission fields (2 of which are in the northern sky). I first present the techniques of reduction, processing and calibration of the ISOPHOT cosmological data. I show that there is a good agreement between PHOT and DIRBE on extended emission, thanks to the derivation of the PHOT footprint. Final maps are created, and the survey is confusion limited at sc = 45 mJy.
I present then the techniques of source extraction and the simulations for photometry needed to build the final catalog of 106 sources between 180 mJy (4 sc) and 2.4 Jy. The complementary catalog is made of 90 sources between 135 and 180 mJy. Galaxy counts show a large excess with respect to local counts or models (with and without evolution), only compatible with strong evolution scenarios. The Cosmic Infrared Background (CIB) is resolved at 4 %
at 170 µ m.
The identifications of the sources at other wavelengths suggest that most of the sources are local, but a non negligible part lies above redshift 1.
I have developped a phenomenological model of galaxy evolution in
order to constrain galaxy evolution in the infrared and to have a
better understanding of what the FIRBACK sources are. Using the local
Luminosity Function (LF), and template spectra of starburst galaxies,
it is possible to constrain the evolution of the LF using all the
available data: deep source counts at 15, 170 and 850 µ m and the CIB spectrum. I show that galaxy evolution is dominated by a high infrared luminosity population, peaking at L = 2.0 × 1011L. Redshift distributions are in agreement with available observations. Predictions are possible with our model for the forthcoming space missions such as SIRTF, Planck and FIRST.
Cosmology -- Galaxies: Formation, Evolution, Counts -- Observation: Infrared, Submillimeter, Space -- Luminosity Function -- Extragalactic Background