Dottorato - PhD thesis
Area Tematica: RSN 1 - Galassie e cosmologia
Referente: Veronica Strazzullo (
Titolo: Optical-to-radio galaxy evolution studies in high-redshift cluster environments
Decorrenza: 19.05.2025
We propose a range of projects in the context of a broader investigation exploiting a set of observations acquired over the past few years on major facilities (HST, VLT, JWST, Spitzer, MeerKAT, GMRT, ALMA, and JVLA). These projects investigate different aspects of galaxy evolution in the early phases of the formation of the most massive galaxy clusters, focusing in particular on the transition between the very actively star-forming galaxy populations in protocluster environments at z>2, and the largely quiescent massive galaxies that characterise cluster cores already by z~1.
The observations at the core of this project focus on the archetypal protocluster around the Spiderweb radio galaxy (z=2.16, Pentericci et al. 1997, Miley et al. 2006), and on a representative, homogeneous, uniformly selected sample of five among the rarest, first massive clusters known emerging from the cosmic web, at 1.4<z<1.7 (Strazzullo et al. 2019, 2023).
The student will also take advantage of in-house theoretical models of galaxy formation and evolution, coupled with high-resolution and large cosmological boxes to interpret this exquisite observational data set in a cosmological context. The GAEA semi-analytic model critically enables a probe of large simulated volumes (necessary to identify rare objects such as our targets) with state-of-the-art physical modelling allowing predictions over the entire wavelength range covered by our observations. The Dianoga zoom-in hydrodynamical simulations offer a state-of-the-art, complementary and independent theoretical rendition of very massive haloes comparable to our target clusters.
The combination of (in-hand, ready to be analysed) optical/NIR to radio observations including HST (ACS, WFC3), VLT (FORS2, HAWK-I, MUSE), JWST (NIRCam), Spitzer (IRAC), ALMA, MeerKAT, uGMRT data (additional optical/NIR observations are currently scheduled or have been proposed; X-ray observations are also available for all the targets) enables specific investigations of galaxy population properties in these structures from the cluster core out to the cluster outskirts, focusing on the investigation of star formation, quenching, stellar mass assembly and structural evolution in massive galaxies across the cluster virial volume, and on the direct comparison with theoretical expectations to investigate physical mechanisms and evolutionary pathways, at a cosmic time corresponding to a fundamental transition phase for both massive clusters and their galaxy populations.
The availability of a broad range of observations from major facilities, and the extensive in-house expertise on both the observational and theoretical aspects of this project, make it an exciting opportunity for a PhD student. The project offers exposure to multiple important aspects of current galaxy evolution studies at z~2, with a clear-scope, well defined primary investigation leading to important future developments also in relation to the capabilities of current and future (e.g. ELT, SKA) major facilities.
