Constraining star formation rates and AGN feedback in high-z radio galaxies

Contraindre les taux de formation d'étoiles et la rétroaction des noyaux actifs dans les radio galaxies distantes

Theresa Maria Falkendal (1)

1 IAP - Institut d'Astrophysique de Paris

The evolution of galaxies is something that is still not well understood. The cosmic star formation rate density peaks between 1 < z < 3. It is therefore important to investigate the high-z Universe and the mechanisms which triggers or quenches star-formation in galaxies. In this thesis I investigate the effects of AGN feedback by studying high-z radio galaxies (HzRGs). For a sample of 25 HzRGs at 1 < z < 5.2, I add new ALMA data and determine the star formation rates (SFR) by multi-wavelength spectral energy distribution fitting. The ALMA data reveals that the mm continuum emission can be complicated, with contributions from several thermal dust emission components and/or synchrotron emission. The new estimated SFRs are 7 times lower than in previous studies. We might therefore be observing the effect of the AGN suppressing the growth of the host galaxy. For one source I explore the possibilities of constraining the gas Physics of the host galaxy and the halo gas by combining MUSE and ALMA data cubes. Quiescent ionized halo gas is detected, which coincide with a molecular gas reservoir detected with ALMA in [C I]. These observations probe the complex multi-phase halo gas and show the power of multi-wavelength observations.

L’évolution des galaxies reste assez mal comprise. La densité de formation piquant entre 1

Mots clés: Galaxy evolution; High-z; Star formation; Radio galaxies; Active galactic nuclei; Circumgalactic medium

Mots clés: Evolution des galaxies; Grand décalage spectral vers le rouge; Formation d'étoiles; Radio galaxies; Noyau actif de galaxies; Milieu circum-Galactique

Domaines: Astrophysique galactique [astro-ph.GA]

Theresa Maria Falkendal. Constraining star formation rates and AGN feedback in high-z radio galaxies. Galactic Astrophysics [astro-ph.GA]. Sorbonne Université, 2018. English. ⟨NNT : 2018SORUS248⟩. ⟨tel-02475869⟩