Starburst and old population in z=3.8 radio galaxies with Pégase.3
Abstract
Distant radio galaxies, hosted by massive ellipticals, follow the galaxy evolution process on an extremely large (0 >= z >=7) time-scale >= 1012Gyrs, up to primeval galaxies. The new evolutionary code Pégase.3 predicts on similar time-scales, the coupled stellar and dust emissions of various galaxy types: starbursts and Hubble sequence types. All z=0 templates are fitted on local observations at ages ~=13 Gyrs (except irregulars at 9 Gyrs). The multi-λ spectral energy distributions (SEDs) of two z=3.8 radiogalaxies, including the most recent Herschel data from the HeRGÉ consortium, are interpreted in the observer's frame by Rocca-Volmerange et al. (2012) with Pégase.3. The apparent SEDs are fitted at best with the sum of a young starburst and an older early-type population, an AGN simple model is taken into account. These results favor massive gas-rich mergers at work in evolved galaxies at z~=4. Massive starbursts would be at the origin of galaxy evolution initiated at the earliest epochs (z for >=10). The possible relation with super massive black holes is still debated.
- Publication:
-
The Intriguing Life of Massive Galaxies
- Pub Date:
- July 2013
- DOI:
- 10.1017/S1743921313004365
- Bibcode:
- 2013IAUS..295...78R
- Keywords:
-
- galaxies: formation;
- galaxies: evolution;
- radio continuum: galaxies;
- infrared: galaxies;
- stars: formation