4 juin - 7 juin 2013


Atelier PNCG : IR galaxies

Atelier PNCG : Clair-Obscur Extragalactique II - Recent Results on IR Galaxies

An SF2A/NAC workshop brought to you by Maarten Baes, Matthieu Béthermin, Médéric Boquien (chair, F), Denis Burgarella, Karina Caputi (chair, NL/B), Rowin Meijerink, and Emma Rigby.

Understanding how galaxies formed and evolved through cosmological time is a key goal in astronomy. Over the last decade, our understanding of the physical processes involved in galaxy evolution has made significant progress. But do we really have a reasonable understanding?

To study galaxy evolution, the optical regime has been historically preferred because optical photons are easier to detect. However, it is now clear that optical observations only lead to a biased view of galaxy evolution. Exploring the IR regime is crucial to obtain a complete picture, since a large part of the bolometric luminosity of galaxies is emitted in the IR (up to ~90% at z~1!). On the one hand, the light of old stars is completely shifted to near- IR wavelengths for galaxies at z>1, and thus IR observations are essential to derive accurately their stellar mass and study the history of galaxy stellar mass assembly. On the other hand, the mid-/far-IR/sub-millimeter light traces the dust heated by recent star-formation and black-hole activity, and provides constraints on the star formation history. This is intimately linked to the molecular gas reservoir in galaxies, which fuels new stellar generations. Studying both the dust and gas emission, produced in the interstellar media of galaxies from low to high redshifts, is necessary to understand how the gas- star-dust cycle has shaped galaxy evolution since the early Universe until today.

This SF2A workshop, organized with the Nederlandse Astronomenclub, will bring together observational and theoretical astronomers from the two societies. The latest results and projects, will be discussed during the meeting, including a large variety of results being obtained with ground-based and space facilities, from e.g. VLT, VISTA and HST in the near-IR, through e.g. Spitzer, Herschel, Planck, and ALMA in the mid-/far-IR/sub-millimeter. The final aim of this workshop is identifying key open questions in galaxy evolution, and the possibility of answering them with upcoming IR facilities. We particularly encourage young astronomers to present their work, and actively participate in all the discussions.

Mardi 4 juin
13:45-14:05The panchromatic view of dust and star formation in Andromeda (Sebastien Viaene)
14:05-14:25The M33 CO(2-1) survey - star formation and molecular cloud formation (Clément Druard)
14:25-14:45The Herschel Reference Survey (Alessandro Boselli)
14:45-15:05Dust properties of the 323 nearby galaxies of the Herschel Reference Survey (Laure Ciesla)
15:05-15:25How to improve SAMs: new relations between dust, gas, and attenuation in galaxies at kpc scales (Médéric Boquien)
15:25-15:45Discussion: nearby galaxies as tools to understand galaxy formation and evolution (Alessandro Boselli)
16:05-16:25Emission lines properties from broad-band photometry: impact on selection and physical parameter estimation (Stephane De Barros)
16:25-16:45Excitation of hot molecular gas in luminous infrared galaxies (Rowin Meijerink)
16:45-17:05Extreme [CII] line cooling in radio-galaxies: a signature of AGN-driven turbulence? (Pierre Guillard)
17:05-17:25A direct estimate of the molecular gas history of the Universe through CO luminosity functions and H2 mass function evolution (Mark Sargent)
17:25-17:45Discussion: gas in all states in galaxies (Rowin Meijerink)
Mercredi 5 juin
14:20-14:40FitSKIRT: Oligochromatic UV to NIR fitting of dusty galaxies (Gert De Geyter)
14:40-15:00Photometric redshifts and stellar mass assembly in the COSMOS field out to z=4 (Olivier Ilbert)
15:00-15:20Chasing AGN at z>1: a New IR Diagnostic (Karina Caputi)
15:20-15:40UV-to-IR spectral energy distributions of galaxies at z>1: the impact of Herschel data on dust attenuation and star formation determinations (Veronique Buat)
15:40-16:00Discussion: determination of physical parameters of galaxies from SED fitting (Véronique Buat)
16:30-16:40UltraVista: ultra-deep YJHK and NB118 survey in the COSMOS field (Olivier Le Fèvre)
16:40-17:00Searching for protoclusters in the far-infrared with Herschel/SPIRE (Emma Rigby)
17:00-17:20On the redshift evolution (0 < z < 4) of dust attenuation and of the total (UV+IR) star formation rate density (Denis Burgarella)
17:20-17:40The redshift-evolution of the distribution of star formation among dark matter halos as seen by Herschel and Planck (Matthieu Béthermin)
17:40-18:15General discussion: open questions and general outlook on IR astronomy (Médéric Boquien & Karina Caputi)