CLASH-VLT - The Largest Spectroscopic Survey of Massive Galaxy Clusters to Date: a new reference dataset for cosmology, galaxy evolution, and structure formation

• Applicant: Dr. Italo Balestra
• Subject Area: Astrophysics and Astronomy
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 257107252

• Final Report Year: 2017

Final Report Abstract

We exploited a combination of new data of unprecedented quality (i.e. the CLASH HST Multi-Cycle Treasury program, the HST Frontier Fields program, the Subaru wide-field imaging, our large CLASH-VLT spectroscopic campaign, and the recent MUSE integral-field spectroscopy) and the gravitational lensing effect around massive galaxy clusters to address some fundamental questions about dark matter, dark energy, structure formation, and galaxy evolution out to the epoch of reionization. The quality and size of the data used were key in achieving new break-through results. In particular, our large spectroscopic campaign had a central role in our project, providing thousands of spectroscopic redshifts for cluster member galaxies and other intervening structures along the line of sight, including high-z, highly magnified, lensed background galaxies. The large number of spectroscopic redshifts of lensed galaxies has allowed us to produce new state-of-the-art lensing models, which were key in obtaining several new results. To summarise some of the most important ones: We were able to accurately measure the dark-matter mass profile shapes in clusters using hundreds of multiply imaged sources; we could study the dynamics of cluster galaxies in unprecedented detail and we could compare the reconstructed cluster mass profile obtained from the dynamics with that obtained from other methods, i.e. gravitational lensing, X-rays; by comparing the mass profile from the dynamics of galaxies and that obtained from lensing, we were able to put constraints on f(R) modified-gravity models at the scales of massive galaxy clusters we discovered candidate primordial globular clusters in very faint, star-forming galaxies at high redshift (z~6).

Publications

• CLASH-VLT: A highly precise strong lensing model of the galaxy cluster RXC J2248.7-4431 (Abell S1063) and prospects for cosmography. 2016, A&A, 587, 80
  Caminha, G. B.; Grillo, C.; Rosati, P.; Balestra, I.; Karman, W.; Lombardi, M.; Mercurio, A.; Nonino, M.; Tozzi, P.; Zitrin, A.; Biviano, A.; Girardi, M.; Koekemoer, A. M.; Melchior, P.; Meneghetti, M.; Munari, E.; Suyu, S. H.; Umetsu, K.; Annunziatella, M.; Borgani, S.; Broadhurst, T.; Caputi, K. I.; Coe, D.; Delgado-Correal, C.; Ettori, S.; Fritz, A.; Frye, B.; Gobat, R.; Maier, C.; Monna, A.; Postman, M.; Sartoris, B.; Seitz, S.; Vanzella, E.; Ziegler, B.
  
• CLASH-VLT: Dissecting the Frontier Fields Galaxy Cluster MACS J0416.1-2403 with ∼800 Spectra of Member Galaxies. 2016, ApJS, 224, 33
  Balestra, I.; Mercurio, A.; Sartoris, B.; Girardi, M.; Grillo, C.; Nonino, M.; Rosati, P.; Biviano, A.; Ettori, S.; Forman, W.; Jones, C.; Koekemoer, A.; Medezinski, E.; Merten, J.; Ogrean, G. A.; Tozzi, P.; Umetsu, K.; Vanzella, E.; van Weeren, R. J.; Zitrin, A.; Annunziatella, M.; Caminha, G. B.; Broadhurst, T.; Coe, D.; Donahue, M.; Fritz, A.; Frye, B.; Kelson, D.; Lombardi, M.; Maier, C.; Meneghetti, M.; Monna, A.; Postman, M.; Scodeggio, M.; Seitz, S.; Ziegler, B.
  
• CLASH-VLT: constraints on f(R) gravity models with galaxy clusters using lensing and kinematic analyses. 2017, JCAP, 07, 023
  Pizzuti, L.; Sartoris, B.; Amendola, L.; Borgani, S.; Biviano, A.; Umetsu, K.; Mercurio, A.; Rosati, P.; Balestra, I.; Caminha, G. B.; Girardi, M.; Grillo, C.; Nonino, M.
  
• Paving the way for the JWST: witnessing globular cluster formation at z > 3. MNRAS, 2017, 467, 4304
  Vanzella, E.; Calura, F.; Meneghetti, M.; Mercurio, A.; Castellano, M.; Caminha, G. B.; Balestra, I.; Rosati, P.; Tozzi, P.; De Barros, S.; Grazian, A.; D'Ercole, A.; Ciotti, L.; Caputi, K.; Grillo, C.; Merlin, E.; Pentericci, L.; Fontana, A.; Cristiani, S.; Coe, D.